Model Engine Maker
Engines => Your Own Design => Topic started by: Brian Rupnow on September 04, 2017, 09:10:34 PM
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I have always been intrigued by the Stephensons Link reversing mechanism that was used on some steam engines. While searching for information about it, I was directed to "GrabCad", a site where 3D models can be downloaded free of charge. There is a complete and very detailed model of a small two cylinder steam engine, 3/4" bore x 3/4" stroke, with the reversing mechanism on it. It is quite a lovely model, and it is obvious that many of the major components are castings. This afternoon I have been playing on my CAD system to see what would be involved in making this engine from bar stock. This is what the engine looks like as downloaded.
(http://imageshack.com/a/img923/8546/yOkfvv.jpg)
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The most complex casting is that of the cross-head and the two supporting legs which hold it in position. If I was a real fanatic about it, I might be able to carve this from one lump of metal, but it would be a very trying exercise---and there are two of them.
(http://imageshack.com/a/img923/4544/NHEOGR.jpg)
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It appears to me that this could be fabricated from three pieces of either steel or brass, silver soldered together. It wouldn't be nearly as pretty as the casting, but should function the same, and be much, much easier to fabricate. The round portion is pretty straightforward lathe work, and the legs could be fabricated from either one or two separate pieces. It might be tricky to turn the radius in the leg where it has to match the outside diameter of the round cross head, but that is simply a matter of fixturing.
(http://imageshack.com/a/img922/9492/OGvtH5.jpg)
(http://imageshack.com/a/img922/422/gJwMVK.jpg)
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Like I said--Not nearly as pretty, but much closer to the scope of what I feel I can fabricate from bar stock.
(http://imageshack.com/a/img924/7361/29AL2B.jpg)
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I'd be interested in seeing how this develops Brian :)
I have contemplated trying to make something similar from bar stock, my thoughts were to fabricate the standards from 5 pieces - the crosshead guide cylinder, 2 supporting legs and the 2 outer webs being soldered in place.
I've never made anything like that so not sure how practical it is but I'd like to give it a try :)
Peter
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Follow along Peter. I will post the results that I get. The hardest part of the entire engine is probably those two fabricated stands.
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That looks to be modeled upon the Stuart D10
If you are looking for a simpler (and IMHO more elegant) solution you could look at something based similar around the Stuart 'Twin launch' or the 'Compound launch'
(http://www.stuartmodels.com/graphics/products/cache/s_360_420_63.jpg)
Nick
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Beautiful engine Brian. Would it be possible to have the lower post made by 3-D printing. However, your 3-piece design looks fine. Looking forward to you build.
Thomas
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Thomas--If I cared to spend the money, I'm sure I could have it 3D printed. However, I would rather fabricate the parts. For me, the important aspect of making something like this is more about making a functional part with the machinery I have in my little shop.--Brian
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This is going to get interesting. Although the solid models have been designed in inches, it appears that in some places the numbers used may be direct conversion from metric. Also, the bolts used are 7BA and 8BA, which I am not familiar with. I will be converting the fasteners to Imperial sizes, mostly #5-40 and #4-40.:eek:
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Hi Brian, I think I have the plans for the engine shown in your 1st post. Somewhere along the line I downloaded them. (Free) I created a 3D model of it in Pro-Engineer years ago as an "excercise". I'll see if I can find them for you. I think the plans were in German though. But, the details & dimensions are there...
John
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Hi Brian, I think I have the plans for the engine shown in your 1st post. Somewhere along the line I downloaded them. (Free) I created a 3D model of it in Pro-Engineer years ago as an "excercise". I'll see if I can find them for you. I think the plans were in German though. But, the details & dimensions are there...
John
John--Thank you for the kind offer, but no thank you. I never trust 3D models downloaded from Grab-cad, and by the time I get finished changing everything to suit a fabricated assembly with #4 and #5 bolts, it will be changed so much that drawings would be meaningless. :pinkelephant:---Brian
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Easiest way to fabricate the trunk and standard would be to turn the flange and guild as one piece, legs cut from 1/8" tee and bent to form the vertical ribs, solder all these onto a flat bar and then cut that to form the feet after soldering.
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I made the one for my barring engine from cast iron bar, and just made the webs as separate decorative parts glued into some shallow slots.
(http://lister-engine.com/coppermine/albums/userpics/10026/normal_Barring_Engine_001_25-09-16.jpg)
Phil
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Easiest way to fabricate the trunk and standard would be to turn the flange and guild as one piece, legs cut from 1/8" tee and bent to form the vertical ribs, solder all these onto a flat bar and then cut that to form the feet after soldering.
Jason, have you uploaded a build log of doing this or something similar ? Now that my Grasshopper is just about finished I'd like to try fabricating parts so I'm interested in how you did it :-)
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Not done one with a round trunk guide, the Tidman would be about the nearest but that was a lot bigger "box" section with flat surfaced crosshead guides.
Infact the 10V that Brian is looking at could be done very easily with the two sloping parts cut from tee section, you would not even need to do any bending.
1. angle cut bottom
2. cope cut vertical to fit the trunk guide at the complementry angle
3. taper sides
4. cut web to shallow eliptical profile.
The main reason for using tee section is it means there are less bits to hold together while soldering but at this size if tee is not available it could easily be milled from a bit of 3/4 x 3/8 flat bar.
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Thanks, I envisaged soldering the web but using T cross section makes more sense - I'd like to give it a try but possibly cut the sloping web as a straight line to simplify things a bit :-)
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The base casting for this engine is only 5/8" deep, and as a consequence, both the flywheel and the crankshaft extend below the bottom of the base. This makes it necessary to use a built up sub base with the engine as designed, to give clearance for the crankshaft and flywheel to rotate. I have kept all of the features of the upper surface, but extended the "skirt" another 1/2" so no sub base is required. The original base casting had sloping sides, partly for ease in casting the part and partly for "aesthetics". I have opted to make the sides vertical for ease of machining. This will have no impact on how the engine functions.
(http://imageshack.com/a/img924/399/rGoH1a.jpg)
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Hi Brian,
The cad drawing of the engine depicts a Stuart D10 with the optional reversing gear. If you want to build one why not purchase a Casting kit(s) from Stuarts (approximately £160) or alternatively just the drawing at £11.40. Or am I missing something here, is it the challenge of building something without using casting that is the appeal ? In my very humble opinion the D10 is one of most attractive steam engines especially with the added interest of reversing gear and or feed pump. Here is photo the one I have just completed.
regards
Ian
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Johno--I have no desire to buy a casting kit. The whole reason for doing something like this is to improve my machining skills and the joy of machining. It might even possibly show others that they can make quite a respectable engine without having to lay out a lot of money for a casting kit.---Brian
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The only other radical departure from the "casting style" is the connecting rod. On the left you can see the original "as cast" connecting rod and rod cap. On the right is the same con rod and cap machined from solid. Now remember, I have shown the "machined" con rod with no radius on any of the sharp corners. If you wanted to, for "aesthetics", you could file in any number of nice radii on the machined rod, but other than for "pretty" they aren't really needed.
(http://imageshack.com/a/img924/2879/okcFX7.jpg)
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Hi
I'm new to this site and model Engineering, I am a printing engineer by trade and I am planing to build a Stuart 7A vertical engine without buying any expensive castings. I was pleased to read your threads to hear other enthusiasts have the same idea. I have purchased the drawings for the engine and plan to fabricate the parts and find your posts helpful. Many thanks. Andy
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There was one more change. The original cylinders had sheet metal lagging around them (and probably insulation between the cylinder body and the lagging.) Since I will be running this engine on compressed air instead of steam, it is much easier for me to do away with the sheet metal lagging and make the outer body of the cylinders the same shape as the lagging used to be. I have also changed out the original bolts and nuts to all #5-40 socket head capscrews. I know this last step with the bolts will have many of the purists squealing in agony, but I like the socket head capscrews much better.
(http://imageshack.com/a/img923/9560/Wup4G3.jpg)
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It might even possibly show others that they can make quite a respectable engine without having to lay out a lot of money for a casting kit.---Brian
Often as not buying a casting set is cheaper than buying bar stock to make an engine out of and takes less time to machine ::)
Jo
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Manufacturing a component from bar stock clearly requires good machining skills. Equally, choosing the most appropriate method holding a casting, the sequence of the machining operations is part of fun when working with castings. Also, an engine made up of predominantly castings has a look and feel about it that to my mind follows full size practice and hence the appeal. Model Engining is a broad Church, each to their own. Good look with your engine, socket head screws and all, which I am sure will look the part given the 'all over machined' look, the important thing is for us all to enjoy what we are doing.
Ian
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I'm just tappin' me foot waitin' for the talking to stop and the chips to start flying.... Brian always has an interesting way of doing things. I love "not normal"....
Pete
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Jeez Pete--That's the nicest thing anybodys said to me so far today---
So--To build this, I can use brass, steel, or a combination of brass and steel. The round center portion can be either material with no penalties. The legs are going to be nasty to cut the half round in where they mate to the cylinder. Since brass is so much easier to machine than steel, I see the legs as definitely made from brass. The feet can be either metal, again with no penalties. I have all of the material in stock to make it this way. I'll have to think a bit about the round part--I have the material for it in steel but not in brass.
(http://imageshack.com/a/img922/7514/kifmYH.jpg)
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The only other radical departure from the "casting style" is the connecting rod. On the left you can see the original "as cast" connecting rod and rod cap. On the right is the same con rod and cap machined from solid. Now remember, I have shown the "machined" con rod with no radius on any of the sharp corners. If you wanted to, for "aesthetics", you could file in any number of nice radii on the machined rod, but other than for "pretty" they aren't really needed.
The big-end of your 'machined' con rod is shown as turned, so why not turn the whole thing while you are at it, and make it look more conventional. To do this, you are just left with a little filing (another good skill to practice) where the turned exterior of the forked top meets the gudgeon pin bosses.
BTW, I built a Stuart Double 10 from castings getting on for 50 years ago, as my first major project, completing it in the summer between school and uni. And believe me, Brian, it taught me a hell of a lot about machining. It is sitting on the mantlepiece behind me as I type, and I can still turn it over by blowing into the steam pipe.
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I'll have to think a bit about the round part
We call that bit a trunk guide in English. The crosshead is the thing it guides. ;)
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ChuckKey--You are right, of course. It should be called the "cross-head guide". I noticed that error as soon as I had posted, but didn't know if anybody would catch it or not.---Brian
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ChuckKey--You are right, of course. It should be called the "cross-head guide". I noticed that error as soon as I had posted, but didn't know if anybody would catch it or not.---Brian
Brian, when it is round it is called a TRUNK guide as Chuck said not a cross head guide even though it does guide the crosshead.
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I suspect that many of naming conventions derive from old English at a time when such engines were at the forefront of technology and naming conventions were developing rapidly . As others have said; 'trunk guide' seams common for a competent that encircles the crosshead, 'crosshead column' or just 'column' appears to be used for a component where the crosshead slides against it. In either case it appears that it is seldom or ever referred to a the 'cylinder support column' which is its other prime function. Stuart's name for such a component is 'standard'.
In the UK, within engineering, as is other things, there still remains regional differences for the same thing. Does any body want to share a 'glossary of terms'. If so, the debate could be great fun and go on for ever.
Ian
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Rectangular section guides for crossheads are usually called slidebars, and come as:
1 bar passing through a rectangular hole in the crosshead, used in marine and loco practice
1 bar with a slot through the middle, or two bars to the same side of the gudgeon pin, with an H-section crosshead slipper, often used in marine engines,
2 bars either side of the gudgeon pin, with an 'alligator' crosshead
3 bars to one side,with a T-shaped slipper, these two often used on locomotive outside cylinders,
4 bars with a flat slab crosshead, used on horizontal stationary engines and locomotive inside cylinders.
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Or they don't need to be bars at all in which case I would just term them cross head guides, bit like these ones on the Tidman engine I made which are a machined part of the "casting"
(http://img.photobucket.com/albums/v156/jasonballamy/Engineering/Tidman%20Organ%20Engine/DSC00569_zpsf6dznygh.jpg)
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Okay--how are we going to do this?---Maybe--Start with a piece of 1/2" flatbar, with the overall height and width and thickness machined to match the outside of the legs.
(http://imageshack.com/a/img923/7794/wUyuNe.jpg)
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Stick it in the mill vice with a piece of aluminum packing on both sides and drill then bore the 13/16" diameter hole as shown. The aluminum packing on both sides protects the jaws of my mill vice, and more importantly, prevents ripping at the top of the legs where they become a sharp corner.
(http://imageshack.com/a/img924/9229/6EdfMt.jpg)
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Then we go in and hog away the center material, leaving it as shown.
(http://imageshack.com/a/img923/5623/SZdc2e.jpg)
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I turn the cylindrical portion to the correct finish diameter and the turned down section is at finished length. The larger diameter is left about 1" longer than it will end up so I can chuck it in the lathe. I will probably make a holding fixture to hold both parts in the correct relationship to each other, and do my silver soldering at this stage.
(http://imageshack.com/a/img924/2245/G2rhyX.jpg)
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At this stage, I will drill and ream the center hole to finished size in the lathe, then over to my chuck on my rotary table to machine the slot in.
(http://imageshack.com/a/img923/8854/lwSDNW.jpg)
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And now its back into the lathe and parted off to the correct length. The feet on the bottom of the legs will be silver soldered on as separate pieces.
(http://imageshack.com/a/img923/1686/IlMY79.jpg)
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That was virtually interesting, in an imaginary sort of way... :Lol:
Good way to work out the sequence, maybe you should model the chuck to ensure that the jaws clear the legs?
:popcorn:
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That was virtually interesting, in an imaginary sort of way... :Lol:
Good way to work out the sequence, maybe you should model the chuck to ensure that the jaws clear the legs?
:popcorn:
The legs stick out of the chuck, not inside it.--And by the way, I do have a model of the chuck. in fact, I have a model of darn near everything. :Jester:
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Hi Brian, that looks like a great way to proceed. It makes me feel that even I could do it. But please show good pictures of your fixtures to hold it all in place for the silver soldering. That is the area I have the most difficulty.
Following along on a great looking model.
MJM460
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Brian, why not solder the feet on at the same time.
1. you won't risk melting the previous joint
2. you can machine the bottoms of the feet at the same time as the trunk is bored so the whole thing will sit true on the base
3. While you still have the chucking piece the feet can be squared off so it does not matter if the move slightly while soldering, drill for foot fixings at same setting.
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Good plan, Jason. I was thinking the same thing after I went to bed last night.--Brian
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I paid $43 this morning on the way to my temporary "office job" for a piece of 2" x 1/2" x 6" long brass flatbar and a piece of round brass 1 1/2" diameter x 6" long. I ran out of design work at noon, so I came home and played in my shop this afternoon. I have the two pieces cut from flatbar to finished size (setting on the lathe way) and one end of the round bar turned to 1 3/8" diameter and 13/16" diameter on one end. The finished bore of the round bar will be 5/8". I decided to drill and ream to 1/2" diameter full length of the turned section while it was still in the lathe to give good concentricity, and to #1--take away some of the mass where I will be silver soldering and #2--to give me a "sized hole" to act as a good register for an improvised fixture which will hold the pieces together in the correct relationship while I solder them.
(http://imageshack.com/a/img924/5503/10pzyn.jpg)
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Fixture rod to hold things in correct relationship for silver soldering.
(http://imageshack.com/a/img923/8104/SZZ9Qf.jpg)
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Rather than turn down that length to 1/2" why not use 1/2" bar and a separate bit of say 5/8" stock drilled 1/2" and slipped onto the pin.
Infact if your hole in the triangle is good you just need a block to hold the other part upto height.
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I paid $43 this morning on the way to my temporary "office job" for a piece of 2" x 1/2" x 6" long brass flatbar and a piece of round brass 1 1/2" diameter x 6" long.
:o A casting is looking a lot more reasonable cost than making from bar stock :paranoia: That is the same sort of price as buying a standard for a Stuart No 4, which is 4 9/16" tall...
Jo
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Well that only because Brian chose to use brass. had he done it for steel he could make 3 or 4 standards for the price of one Stuart 10V item and that is not allowing for transatlantic postage costs.
But I suspect like me Brian enjoys the challenge of designing and making the fabrication, anyone can face off a casting and poke a couple of holes in it ;)
That 12" high Tidman standard that I made could be done for less than £20 if you cut your own sheet and it gave me several weeks of enjoyment. now what would something that size cost as a casting £150 plus?
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I am still waiting to see you make a Clarkson Steeple engine or Mery out of bar stock ::)
Jo
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Well at least the Clarkson bits would be machinable and not chilled, that should be quite easy to do, Mery would take a bit more time but not impossible plus i could at least make it to a scale that fits my machines :)
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So we look forward to seeing you build one of each of those then :ThumbsUp:
Jo
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Too many other unique and unmodelled engines to do first, that is also one of the advantages of fabricating you can make whatever you like not what someone else liked.
You can also model them closer to the original too, not just copy the shortcuts the other designers took either through lack of research material available at the time or having to compromise detail that would have needed more expensive castings to reproduce.
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This from the boy who wanted both of those casting sets :lolb:
Jo
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This from the boy who wanted both of those casting sets :lolb:
Jo
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He's a reformed character these days Jo. New Jason has consumed old Jason.
He also now has an additional mill and 1/2 a trailer full of tooling delivered this week to help and assist in the creation of his fetish. - Some form metal and some fondle metal. ;) ;D
Nick ;)
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This from the boy who wanted both of those casting sets :lolb:
Jo
It was only the Mery that I liked
Nick don't tell her that she will only feel the need to go out and get yet another mill to keep up, best not tell her what it did not cost me either her moths will never get over it :LittleDevil: Then again maybe I should put up a picture of my ARC Eurotrade supermarket sweep in another thread to save derailing Brians build.
J
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in another thread to save derailing Brians build.
J
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Fair point. We are being a bit naughty here. - Sorry Brian.
I am watching your progress with interest.
Nick
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Brian, is the fixture rod for silver soldering made from aluminum?
--TIm
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Great thread Brian, I'm looking forward to seeing this progress, it looks like you are off to a great start :)
If I was to make something similar I'd probably want to try making the standard / trunk guide thingy from steel, is a simple Mapp gas torch likely to give me enough heat for soldering if I was to make one the size or a Stuart 10v ?
Peter.
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Hang on, boys and girls--here we go---
(http://imageshack.com/a/img922/4683/reYNvi.jpg)
(http://imageshack.com/a/img922/4008/KkHO8g.jpg)
(http://imageshack.com/a/img923/6132/Rh7xWA.jpg)
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Nice project. Found this a long time ago, maybe you can use something.
http://jean-luc.soumard.pagesperso-orange.fr/bicylindre.htm (http://jean-luc.soumard.pagesperso-orange.fr/bicylindre.htm)
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Looking real good and an ingenious resolve to the approach.
Thomas
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Okay---we are ready for silver soldering. The alignment rod is turned from a bit of scrap aluminum. My original thought was to make it from steel, but there is too much chance of soldering the alignment rod to everything else.
(http://imageshack.com/a/img922/1792/Tx2PUI.jpg)
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Looking good Brian I can see the road you are driving on this.
Jason gave me a good tip that by using 'Milliput' at the joints to visually soften and give some radius to them. And by the time they have a coat of paint on them they will represent a true casting and nobody will know the difference.
You have probably used Milliput and know it behaves nicely and has a nice long cure time to enable any tweaking.
Nick
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Nick---I've never heard of Milliput. what is it? Some kind of body filler?---Brian
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Its a two part sculpting putty, something similar where you are would be Sculpty or Magic-Sculpt. It can be worked with moistened tools for an hour or so which allows it to be shaped into fillets etc in internal corners and does not need sanding when dry like a bondo type filler does.
Brian, when it comes to the feet if you solder on 1/8" material you can then chuck the whole assembly in the lathe and take a skim off the bottom of the feet which will give a nice surface at right angles to the bore so it does not matter if the feet move about a bit during soldering.
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Thanks Jason--That's what I intend to do. How do I get the guide rod out? Well, in a perfect world, I would have just pulled it out. In my world, today anyways, it refused to budge so I drilled it out. The bore in the round part was purposely left 1/8" undersize in case this happened. All in all, other than some very lumpy silver soldering, things went pretty good. I drilled out the guide rod, then drilled to 21/32" full depth, then reamed with a 5/8" reamer full length. Then I dressed the ends of the legs to make them equal---just a light .005" cut while spinning in the lathe. When I go to do the second one, I'll put a bigger tip on my acetylene torch to get a bit more heat into things.
(http://imageshack.com/a/img924/9990/GThVUc.jpg)
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Great thread Brian, I'm looking forward to seeing this progress, it looks like you are off to a great start :)
If I was to make something similar I'd probably want to try making the standard / trunk guide thingy from steel, is a simple Mapp gas torch likely to give me enough heat for soldering if I was to make one the size or a Stuart 10v ?
Peter.
Sorry Peter--I meant to get back to you sooner. I can't speak for Mapp gas, but I haven't had a lot of luck silver soldering with a Propane torch. I have tried, but Propane never seems to get things quite hot enough. I have had my oxy acetylene rig for many, many years, and it works for what I do---mostly. The stuff I silver soldered earlier today should have been done with a larger tip to get even greater heat into the parts for a better flow of silver solder.--Brian
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Jason, I know you have before-during-after paint images of when you have used the product Milliput (and it's US equivalent) Perhaps you could flick a few of them up here to show Brian.
Brian. It's a very forgiving product that if one realises things are not going as planned you can just wipe it away with a wet cloth, have a cup of coffee and re-try with a new mix. It's not 'claggy' or 'cloggy' (don't know how else to describe it) like automotive filler can be at times and can be formed into say e.g. a 1/8" (or whatever) radius with a damp former of the desired size. But once cured it's not easily removed.
I would imagine there are videos on youtube.
Nick
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So, here we are, with the first soldered assembly 99% finished. I still have to drill 4 holes in the top flange, and probably some counterbores in the end of the legs where they reach the foot plate so a #5 shcs can fit flush with the top side of the foot plate. I have to go over everything with a scotchbrite pad to take the filing/sanding marks out. Who can recomend a good pickling solution available in Ontario that I can soak this thing in to get rid of the black "pits" that are marginally below the surface, so can't really be sanded out.---Brian
(http://imageshack.com/a/img923/5702/78OWHd.jpg)
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Who can recomend a good pickling solution available in Ontario
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I don't know about Ontario but in the UK we have lots of Asian food shops. Most of these sell big bags of Citric acid crystals quite cheaply. (no idea what they use it for) This makes an excellent pickling solution.
Nick
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A safe one is citric acid , buy it as a powder mix with water about four teaspoons to the pint , now it’s a bit slow but safe you can dip your fingers in it no problem after all it’s lemon juice , that’s what I use and have made 5 inch gauge loco boilers with it , one caution though if you dip steel parts make sure you fully submerge them else you will get a deep etched line at the liquid surface
but if you want a dangerous one get some sulphuric acid ( battery acid ) but it’s nasty stuff
Sorry Nick you posted while I was typing , it’s a good kettle descaler
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Citric acid is used for brewing and making wine.
but if you want a dangerous one get some sulphuric acid ( battery acid ) but it’s nasty stuff
All acids can be used safely with care, at an appropriate dilution. I have both 99% Sulphuric and Hydrochloric acid - both fume when I take their lids off. One I use to pickle silver solder, the other to clean the lime scale from the basin of the household throne :embarassed: Fleabay can provide most acids at concentrate that I was amazed they would allow to be transported by post :paranoia:
Acid is like any tool: a blunt edge is more dangerous than a sharp one ;)
Jo
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Brian, if you are interested in adding fillets, milliput is available in the states from micro-mark, as both a standard and fine grain formula. I assume they can ship to Canada.
Bill
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Less expensive to order it from UK via Amazon . Saves the UPS border ripoff as well.
https://www.amazon.ca/Milliput-Superfine-White-Epoxy-Putty/dp/B002CNEWAM, free shipping
Sculpture Supply in Toronto has similar materials in larger package: http://www.sculpturesupply.com/list.php?offset=10&sf=searchtext&vl=putty
Gerrit
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This is where I have purchased Milliput when the local hobby shop was out of stock. (They couldn't keep their stuff organized...)
https://www.squadron.com/searchresults.asp?Search=milliput&Submit=
Pete
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Thank you all for the links to putty suppliers. Actually, I was hoping to not have to paint anything. It will all depend on how good I can make my soldered assemblies look. I have about 25 engines now, and the only thing I have ever painted is a pair of red flywheels, and now I can't remember why I painted them.
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I asked on all 3 forums I post in, for pickling formulas. I have been advised to use sulphuric acid, also muriatic acid, and also citric acid. Sulphuric and Muriatic acid scare me a bit, whereas citric acid seems safe enough to work with, but takes longer. Up I went to the Bulk food store and bought a bottle of citric acid powder for $5. I mixed six heaping teaspoons with a pint of hot water, and dropped in the part I made yesterday. It didn't explode nor create a bunch of fizzing bubbles (I was kind of disappointed actually). I will leave the part submerged for 24 hours and then let you know what the results were.
(http://imageshack.com/a/img922/6469/OSdjJ0.jpg)
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I found in the UK that citric acid crystals are so cheap on Amazon that I can use a very concentrated solution and it seems to clean up copper and brass very well.
Incidentally I did use the solution to try an give a new lease of life to an old file (I read somewhere that citric acid works), I was a bit disappointed and couldn't see any difference after a 24hr soak.
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Someone on one of the forums I post on recently had a thread on using an electrolytic method to sharpen old files. The file was sunk in an acidic bath and was the anode (or the cathode, I can never remember which is which), and with a d,c, power supply enough material migrated from the file surface to "resharpen" it.
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Oh my God--It really does work!!! The part has been soaking in my citric acid solution for an hour. I couldn't see any visual changes in the dark areas. (these dark areas were below the main surface of the parts, and could not be removed by sanding nor wire brushing.) I reached down into the container with my scribing tool and scratched a little at one of the dark areas, and was immediately rewarded with the sight of clean brass. This encouraged me to remove the part from the citric acid bath and scrub it under running water with a little brass bristled brush I have that looks almost exactly like a toothbrush. All of the black areas are gone completely. I am totally impressed!!!
(http://imageshack.com/a/img924/3183/9lBkUb.jpg)
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So, here we are, with the first soldered assembly 99% finished. I still have to drill 4 holes in the top flange, and probably some counterbores in the end of the legs where they reach the foot plate so a #5 shcs can fit flush with the top side of the foot plate. I have to go over everything with a scotchbrite pad to take the filing/sanding marks out. Who can recomend a good pickling solution available in Ontario that I can soak this thing in to get rid of the black "pits" that are marginally below the surface, so can't really be sanded out.---Brian
(http://imageshack.com/a/img923/5702/78OWHd.jpg)
Hi Brian,
The original pickling solution was Sulfuric Acid/Battery Acid nasty stuff, I stopped using it when I got married and started a family, switched to Citric Acid not as fast but a lot safer especially with children around. I have on occasion used plain Vinegar which is slower still. For the tourch if I remember my welding you need what is called a "Rosebud" tip, lots of heat spread out.
Regards,
Gerald.
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Gerald--A rosebud tip would be way to big for this stuff. I did have one size larger brazing tip for my oxy acetylene rig, and it seems to be about perfect for heavier stuff like this. It kicks out a much larger, hotter flame but is still small enough to be wielded somewhat easily and direct the heat where I want it to be. I bought my old torch kit about 50 years ago, and it came with 3 different sized brazing tips and a cutting torch head, but no rosebud tip. Any time I've needed more heat than the largest brazing tip puts out, I put on the cutting torch head, but those are pretty rare occasions.
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Glad it worked for you Brian , yes it’s slow but it’s safe esp. if you have ankle biters about
Don’t forget my warning for steel parts the etch line is quite deep
Stuart
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Here is a question I have never asked before. I would like to do some more finish sanding on this part to clean up the last of the file marks. The part has a really odd shape. I have a roll of #280 grit carborundum cloth x 1" wide that I use for cleaning up turnings in my lathe, but it is of course pretty floppy stuff. Ideally, I would like to buy something like a 3/8" wide strip or 1/4" round of this grit, but rigid so I can use it the way I would a file. Somebody must make a thing like that, but I have never seen it. The closest I have seen to it is way back in the day when I was a junior draftsman we had something similar, a flat wooden strip about 4" long x 1" wide with "tear off strips" of sandpaper on it for keeping a deadly point on our drafting pencils.--HOLD ON--Google is my friend. I just found something close to what I was talking about.--Come to think of it, I think my wife has something like that for doing her fingernails.
https://www.amazon.com/DuraSand-Sanding-Twigs-Hobby-Models/dp/B00G14F41E
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something like this http://www.mountainwoodcarvers.com/detail_sanders.htm
Also have a look at Don's Easton or Benson build he showed what he uses to clean up parts to a bright finish
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Thank you Jason.--Now if I can just find a seller in Ontario---
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HaH--Found flat sticks in Kitchener and round ones at Princess Auto. We have a Princess Auto right here in Barrie.
https://www.princessauto.com/en/detail/8-pc-sanding-sticks/A-p8613184e;jsessionid=GYV1XQaNLJH9MRh4yxL9waWV.pal-prod-com1
http://www.chippingaway.com/shop/woodcarving-supplies/sanding-products-manual-and-power/belt-sanders-power-and-hand/sanding-sticks-and-belts/
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Well Sir--I didn't even have to leave my house. I went upstairs and begged an emery board from my good wife (for filing fingernails). I hunted around in my shop and found an ignition points file, and found a new Scotchbrite pad while I was looking for it. The resulting finish is far from being show quality, but it is "good enough" for now. I will consider using a bit of filler and painting them when all is done, but that's a long way off.
(http://imageshack.com/a/img922/8818/YWaXVH.jpg)
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Having made one of the soldered "stands", I now have to make a second one. What did I learn from making the first one. First of all, use a bigger torch head.--I can do that, as I have a larger torch head available. Secondly, when soldering on the "feet", don't hold the bar that ultimately becomes the "feet" endwise in a vice.-As soon as the brass gets hot enough to solder, the brass bar will deform from the pressure of the vice and go all wonky. That is why one foot on the finished stand looks fine, while the other foot has a definite wedge shape to it. I think those are the only major things. These are about the most complex shapes that I have made from brass bits silver soldered together.
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Rather than holding the parts in the vise, I prefer to use small screws to hold them together for the soldering, then go back and grind/mill/file off the screw heads. For brass parts, use brass screws so they dont show.
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I have a can of spray adhesive from the Dollar store which I use to attach wet/dry paper to dowels and paint steer sticks. I also just wrap it around and tape the ends.
Gerald.
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I am really impressed with how well this citric acid works as a pickling solution for cleaning up parts that have been silver soldered together. I had tried mixtures of vinegar and hydrogen peroxide before (as recommended by somebody on one of the forums) but it didn't seem to be very effective. Now I'm wondering about something else--I see that builders of model steam engines don't seen to use flux on their parts which they are silver soldering together. Instead they soak the items being soldered in a pickling solution before they silver solder them, and don't appear to be using any flux. I have always used flux on the parts I am going to silver solder. Who can shed a bit of light on this subject?
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Can't speak to the no-flux soldering, but am intriqued about the citric acid crystals (looks like you found the LorAnn brand, which is the same company that makes the mint baking emulsion I like). Have you ever tried the Sparex #2 solution? Wonder how they compare. The crystals sound a lot cheaper. Think that they would work as well on steel parts? The Sparex-2 is not great on steel, for those parts I had used vinegar.
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Crueby-I'm kind of a babe in the woods when it comes to pickling solutions. I heard that the citric acid will leave a very distinct "ring" on any part of steel that is not fully submerged. In the interest of science, I will stick a short piece of steel rod in the solution I currently have, with part of it not submerged, and report back in the morning. I have never tried the Sparex brand you mention.
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I am part way through the second assembly tonight. My soldered joints are still lumpy, but I did get a lot better "flow out" of the silver solder using the larger torch tip. I would have been finished today, but helping babysit a two year old grandson and having a sore back has cut into my day quite a bit. I hope to finish the second assembly tomorrow morning.
(http://imageshack.com/a/img923/4161/KsIqtB.jpg)
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Best place to find citric acid is the home brew shop, its cheap, and in larger packs than the Super Market. If you want it by the ton, you'll get it in sacks at an agriculture supply place(even cheaper).
Ian S C
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Brian
Those joints look like you exhausted the flux , by that I mean you took to long to get the temp up or you just messed about , not to be disrespectful
I use a tenacity 5 flux , this is a high temp flux and will work on stainless steel , it lasts longer during the heat and is a bit more aggressive in its cleaning action , down side it takes longer to pickle the part
Another reason for your lumpy joint is to much silver solder to soon the flux must be like glass ie clear before you introduce the solder
If you need a resist to keep the solder where you want it use tipex correction fluid
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For me, I suggest that you are in large excess of solder and really short in heat, hence the bulging aspect of the silver solder, which should simply fill the joints and leave a filet, with a "concave" look, all this excess of silver solder was expected to flow down by gravity in the lowest part in a large drop.
Another possibility is that you don't use a free flowing solder with 40% silver content, but a substitute with 20% or less, which doesn't have the same capillary properties.
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I was warned that the citric acid pickling would leave a very definite mark on any part of the steel which was not completely submerged in the acid bath. In the interest of science I stuck a piece of steel in the bath I have, with part of it not submerged. Who-ever told me was absolutely right. It leaves a very visible demarcation line, which can not easily be sanded out.
(http://imageshack.com/a/img922/6728/QF83WH.jpg)
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Stuart and Zephyrin--I hear you. The silver solder I have is Silvaloy 450 45% Solid at 665 degrees C and liquid at 745 degrees C. in the form of a 1.6 mm diameter wire. The soldering paste is a liquid based paste/slurry which is quite old, and the name is scratched off the container it comes in.
By the time I get the brass parts hot enough to accept the silver solder, the flux is all burned off.
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it was me that mentioned it to you about the line glad you have proved it to your self
as to your flux thats you trouble get some new stuff mix to a double cream consistency only mix enough for the job is the best way ( I mix up a small amount in a Tupperware tub and seal it if its a bit dry just add water to get it back , but thats not the recommended way iy me being tight ) as i said before you are exhausting the flux before the melt temp is reached
get some Tenacity 5 its good stuff your SS is ok thats the low melt type
have fun
Stuart
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Thank you Stuart.--I'm an old dog, but I can still learn new tricks. I will try what you have suggested.---Brian
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I didn't show this set-up for slotting the stand when I posted about the first one, so I'm showing it here. The 1.5" diameter is held in the 3 jaw chuck on my rotary table. It's a bit hard to see, but I have a machinists jack under the outboard end. The legs are set to "level" with my machinists level. A hole is drilled thru to 7/16" diameter at each center of the slot, then I plunge thru with a 1/2" endmill at each end, then plunge thru every 1/16" then take one complete pass with the endmill down full length so it is cutting the top and bottom all in one pass. You will notice with this stand that the "feet" are equal in thickness and there is no slant on the top of either foot. That is because I found a better way to fixture the feet before I soldered them on.--Yes, an old dog can still learn new tricks. I still have to machine and file my lumpy solder joints before I part the stand off from the main 1 1/2" diameter, but I think I will save that for tomorrow.
(http://imageshack.com/a/img924/1762/VVD7la.jpg)
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I am really impressed with how well this citric acid works as a pickling solution for cleaning up parts that have been silver soldered together. I had tried mixtures of vinegar and hydrogen peroxide before (as recommended by somebody on one of the forums) but it didn't seem to be very effective. Now I'm wondering about something else--I see that builders of model steam engines don't seen to use flux on their parts which they are silver soldering together. Instead they soak the items being soldered in a pickling solution before they silver solder them, and don't appear to be using any flux. I have always used flux on the parts I am going to silver solder. Who can shed a bit of light on this subject?
I have been silver soldering since I started in high school in 1964 and have always used flux, sometimes just borax but my preference is Tenacity 5. Currently I have WOLVERINE ULTRAFLUX which I picked up at a welding supply, It is not as good as Tenacity. Harris also makes a good flux.
http://www.harrisproductsgroup.com/en/Expert-Advice/tech-tips/silver-brazing-flux.aspx
Regards,
Gerald.
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No work on this project for a couple of days. I have a severe case of Sciatica and the pain in my lower back keeps me from standing at my machines. Fortunately it doesn't bother me when I'm setting down, so I can still do cad work. I did buy material for the engine base, but haven't done anything with it yet. I am anxious to get the last stand finished and move on to machining the base.
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Hope you get to feeling better real soon.
Thomas
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Brian,
The biggest problem with the soldering/brazing job is that all the heat was being absorbed into the piece of bar stock.
You would have had an easier time cutting the trunk free and soldering it like that.
To do more machining you could have turned a recess into the end of a piece of stock that matched the trunk flange and clamped it with a couple of screws.
gbritnell
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Brian,
I have watched a number of your inventive builds over the last couple of years and admire the way you develop solutions to the problems/issues that arise.
I had a wander round a charity bookshop today and came across a two volume set of books which I think would keep you entertained for hours.
The books are entitled:
Ingenious Mechanisms for Designers and Inventors. Volume 1 and 11. It is an American book copyrighted in 1930 by The Industrial Press of New York City. The copy I have dates from 1946 (Seventh edition).
Topic titles include,
Cams and their applications
Intermittent Motions
Tripping or Stop Mechanisms
Reversing Mechanisms
Overload Relief Mechanisms
Interlocking Devices
Reciprocating Mechanisms
and so on.
There are over 1000 pages in the two volumes.
I'm sure if you could find a copy over there you would find lots of new and interesting mechanisms you could possibly build.
Regards,
Colin
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I have a couple of books of that type. They are quite inspiring, and I have built a few of the mechanisms.---Brian
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Brian,
The biggest problem with the soldering/brazing job is that all the heat was being absorbed into the piece of bar stock.
You would have had an easier time cutting the trunk free and soldering it like that.
To do more machining you could have turned a recess into the end of a piece of stock that matched the trunk flange and clamped it with a couple of screws.
gbritnell
George--Thank you for the advise. I'm sure you are probably quite right. There were more things to do after the silver soldering that required the assembly to still be connected to the main round piece of bronze. I'm not entirely happy with the way it went, but all of the solder joints are quite sound, if lumpy. I will machine/file/sand away the lumpy silver solder and remember this lesson for next time. Thank you for stopping by and saying Hi. I consider you to be one of the masters in this small engine world, and I appreciate your help.---Brian
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And now we have two!! The second stand turned out a bit nicer than the first one, mainly due to using a larger torch tip when soldering the joints. Although my solder joints on the second piece I built were quite lumpy, I also had enough build up of solder that when I machined/filed/sanded away the solder I didn't want, I had very few "craters" left below the finished surface. These two stands were probably the most difficult pieces to build. I'm looking forward to machining the aluminum base in the coming week so that I have something to mount these two pieces on.
(http://imageshack.com/a/img924/3899/CkLf5j.jpg)
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Brian
I quick tip for you
if you want to keep your citric acid mix for later use ad One drop of household bleach to the bottle/container
this will keep it fresh
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So two bases made. Are you going to build a pair like Jo usually does? Or make 3...?
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So two bases made. Are you going to build a pair like Jo usually does? Or make 3...?
Chris--Not really sure what you mean here. Those soldered assemblies are not bases. They both fit on a common base, which I haven't made yet. :shrug:
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So two bases made. Are you going to build a pair like Jo usually does? Or make 3...?
Chris--Not really sure what you mean here. Those soldered assemblies are not bases. They both fit on a common base, which I haven't made yet. :shrug:
My goof, base was the wrong word. I had forgotten that this is a twin cylinder engine too. Too many paint fumes from the shop that day!!
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So two bases made. Are you going to build a pair like Jo usually does? Or make 3...?
::) I can see I am getting a bit of a reputation for parallel builds. The only engine that I have more than one of is the triple Orphans. The 5A and Swan are different (but in some ways the same ;) )
Most of my castings sets are singular from now on
Jo
(Did you spot the .... "most" :naughty: )
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Colin, (Twizseven), keep your eye out for Vol. 3 & 4, you will find them interesting as well, pic below. Regards Paul Gough.
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The base for this engine is going to be Ahhhh---Interesting. Nothing horribly complex, just a lot of milling and drilling. I am going to make a simple jig to hold the soldered "towers" in the correct position and mark thru with a transfer punch to establish the 8 tapped holes which hold the towers in place. I find it a bit strange that the pillow block bushings for the crankshaft are mounted 'upside down' to what I consider normal practice. I still have not fully recover from the sciatica pain in my lower back, but at least I feel improved enough today to do a bit of CAD work. I was supposed to be working in my office on the other side of town today, but I phoned over and begged off for today.
(http://imageshack.com/a/img923/4422/tM4EIO.jpg)
(http://imageshack.com/a/img923/5724/ythFkN.jpg)
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This afternoon I have been well enough to dick around with 3D cad, but too sick to machine anything or go to my real job across town. The base for this engine, as originally designed had a lot of machining on it, 80% of which was purely cosmetic. Same for the crankshaft bearings. I have endeavoured to get rid of any machining which was not absolutely necessary for the function of the engine, and it makes for a tremendous difference in the amount of work. The changes shown here will not effect the operation of the engine in any way.
(http://imageshack.com/a/img922/3258/VvlRXI.jpg)
(http://imageshack.com/a/img924/1478/z8GEqW.jpg)
(http://imageshack.com/a/img923/3945/0DMIHA.jpg)
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This is an "overview" of the engine with fabricated cross head guides and simplified base and bearings.
(http://imageshack.com/a/img922/9324/UDSPb1.jpg)
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I have split the center bushing on the crankshaft for ease of assembly.
(http://imageshack.com/a/img922/8012/frb82E.jpg)
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Ordinarily, I don't use transfer punches, instead depending on my DRO's to match all the holes in different parts that have to bolt together. However, in this case I deemed it necessary, for a number of reasons. The 5/8" diameter rods you see sticking out of the top of the brass assemblies (which have reamed 5/8" thru holes) are also fitted into 5/8" reamed holes in the aluminum baseplate. I used a machinists square to align the brass assemblies "square" to the side of the aluminum baseplate, then used a transfer punch to mark thru to the baseplate. I will now put a small, discrete "match mark" on each brass assembly and on it's corresponding home position relative to the base so I don't mix them up later. There is about 0.030" clearance between the top flanges of the brass assemblies. I have a ton of machining to do on the base now, and I know that the brass assemblies will go back together with the base the way I intend them to. Each of the transfer marks will be tapped #5-40 in the base for the bolts which hold the brass assemblies in place.
(http://imageshack.com/a/img924/7805/7YI7V8.jpg)
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Looks real good Brian and I like your new base design.
Thomas
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Very nice!
Watching along...
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I have split the center bushing on the crankshaft for ease of assembly.
(http://imageshack.com/a/img922/8012/frb82E.jpg)
Hi Brian,
Have you seen how the valve linkage is done on a Stuart twin Launch engine? the eccentric connecting rods at done straight without the bend that is in the D10.
Regards,
Gerald.
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Gerald---I have never seen a Stuart engine.---Brian
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It's nicely taking shape and looking great Brian, I like the idea of using the rods to aid good alignment :)
Are you intending to go all the way and make reversing gear ?
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Yes, if you go back and look at my very first post in this thread, you will see that the reversing gear is what made me choose this engine.---Brian
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YOWZAHH!!! We have the two built up brass cross-head guides mounted to a base. There is a lot of work in that base, but I like the way it turned out. I can't get over how small this thing is. I'm not sure what part I will build next, but probably the bearings and crankshaft are the most logical.
(http://imageshack.com/a/img922/1951/8VYOJ1.jpg)
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Way back at the beginning of this thread, I said that it appeared as if some of the engines dimensions looked like they might be straight conversions from metric to Imperial. Not so--it's just that they built this thing with a 9/32" diameter crankshaft. That is a really unusual size.--A quick check of my reamers shows that I do indeed have a 9/32" (0.281") straight flute reamer, but----I don't have an undersize reamer to use for making a built up crankshaft. However, all is not lost. I do have a 5/16" (0.3125") diameter reamer and an 0.3110" reamer for press fits. So--I'm going to bump the crankshaft up from 9/32" diameter to a full 5/16" (0.3125"). I have checked and there is enough room on the bearings and the connecting rods to bump the bosses up by 1/32" to accommodate the larger crankshaft diameter.
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Here I am carving the outboard crankshaft bearings out of some aluminum bronze. Either my endmills are all duller than a hoe, or else this stuff is harder than the devil's horn.
(http://imageshack.com/a/img924/9539/JfxYrS.jpg)
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Your last coment is true it’s hard and slippery brand new EM. HSS only
Now another silver soldering tip you cannot SS it with the normal flux you have Evan my fav T5 , solution is simple just mix a teaspoon of common table salt to the flux mix then it will work ok
It’s the addition of the chlorine ions in the salt that removes the aluminium chelats thus whetting the surface and cleaning the part
Tip given to me by cualloys here in the UK
Nice work in the fabrication work
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Hello Stuart--Fortunately, there will be no soldering on these bearing units. They are carved from solid and mounted.--Brian
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As your build is based upon the Stuart's D10 and as such all original dimensions are imperial. Stuart's are the oldest steam model engine makers in the world and to the best of my knowledge have never used the metric system.
http://www.stuartmodels.com/
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No problems Brian
I posted for info for you and others who may nee the SS some Ali bronze
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Johno
Yes but my namesake company has changed hands many times in the past and things are not as good as in the past still ok but not as good
Now it’s not my company nor have I any affiliation with them but I am a customer
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I'm sure that if 100 engineers/machinists were asked "How do you turn that round bit on either side of the rectangular bearings?" you would probably get 100 different answers that all work. This is what works for me. I machine the bearing blocks to finished size on the outside, put the appropriate bolt holes in, and ream the bore to 1/32" undersize. Then I turn up a short piece of round bar that is a snug fit in the bearing block, coat the round rod with Loctite 638 and assemble as you see them. For the two outside bearings which have 1/16" oil holes in one side, I drilled 1/16" thru the bearing and thru the round rod so that I can Loctite a short piece of 1/16" crs rod thru both bearing and shaft because the cuts taken in the lathe will be interrupted cuts and I wanted the extra insurance that the bearing wouldn't break free from the round rod while I was turning them. The center bearing has an oil hole also, but when I made the two halves I drilled a clearance hole on one half and a #5 threaded hole in the other half, so it will put enough "squeeze" on the stubby shaft that I'm not concerned about it breaking free from the shaft while turning it.
(http://imageshack.com/a/img923/6084/lq0NG5.jpg)
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Good way to turn them. Will you be taking the holes to final size after mounting in the base?
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That's the question, isn't it. What I would like to do, is assemble the bearings into the base, lock everything down, and then drill and ream them to final size "in assembly". That is the way to do it on bushings with a larger bore, but on little stuff like this where there is no possibility of running a boring bar thru everything in one set-up, I have to make it up as I go along.
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..., I have to make it up as I go along.
Thats the really fun part!
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So, very carefully the bushings are turned on their stub mandrels and fitted to the aluminum base. The bushings are all currently reamed to 0.281" during this first operation. A bit of experimenting shows that a 0.281" reamer will pass thru all three bushings after they are installed in the base without wanting to take any large amount of bronze of any of the three bushings, which is very encouraging. The next stunt is to take my 0.311" reamer and take a complete pass thru all of the bushings with it, watching very closely to make sure that the reamer is not being pulled "out of position" by any radically "out of alignment" holes. This seemed to go very well, so now I move up to the final size 0.3125" reamer and slowly run it thru all three bushings. Now for the big test---does a 0.3125" shaft fit thru all three bushings? This is not guaranteed, because if any one bushing was too far out of alignment, the reamer would be quite happy to follow the out of alignment hole. Reamers will not straighten or "true up" a misaligned hole. They are more flexible than you would ever believe. Luck was with me!! A 5/16" shaft does fit thru all three bushings.--a bit reluctantly, but only a bit, and it can be turned when in place. Before I go any farther with things now, I will mount the base to my work-bench, put an 8" v-pulley on the shaft, and after a liberal application of oil I will drive the shaft for an hour with my old half horsepower bale elevator motor. this will take any "stickiness" out of the bushings and should let a shaft rotate very freely, which is what I am aiming for.
(http://imageshack.com/a/img923/43/y8Ef1K.jpg)
(http://imageshack.com/a/img923/1219/c9IupM.jpg)
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That is some very fine machining Brian.
Thomas
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Here we are "running in" the new bronze bushings. I bought that motor from a farmer for $10 about 10 years ago for a replacement motor on my big power hacksaw. Turned out it was only a stuck brush on the big hacksaw motor, so I have kept my red 1/2 HP motor for a "spare". The 8" pulley originally had a 3/4" bore, but I have made up a collection of split bushings so I can run it on 1/4", 5/16", 3/8", and 1/2" shafts. The pulley on the 1750 rpm motor is a 2" diameter, so the crankshaft is turning at about 440 rpm, which seems to be about right for running in bushings. Any faster and it burns them and they end up too sloppy, any slower and it takes too long to get the job done.
(http://imageshack.com/a/img923/6687/HibAwD.jpg)
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Do you use any compound like Timesavers, or just let the metal itself wear in?
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I just let the material itself wear in. If you look at anything which has been machined by reaming or drilling or boring under high magnification, the surface will look a lot like the rocky mountains. All the "running in" does it knock the highest peaks of the mountains. In extreme cases I have used a bit of 600 grit lapping compound, but I try and stay away from that.--Just use cutting oil instead of lubricating oil.
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Chris--I have to revise my last statement. After the motor ran for half an hour the crankshaft bushings were much looser---but not loose enough. These little steam engines really don't like any resistance in the crankshaft bushings at all.---So--I switched out the short piece of 5/16" shaft with the pulley on it for a piece about 12" long, coated it with 600 grit carborundum paste, and using the pulley somewhat like a steering wheel I pushed the shaft thru all 3 bushings with a twisting in and out motion for a couple of minutes, making sure at all times that the shaft was engaged with all 3 bushings. (It wouldn't do much good if it was just a rotating movement--that would give annular grooves around the inside of the bushing.) Pushing the shaft in and out and turning it at the same time very quickly cut a couple of tenths off the inside of the bushings. After cleaning up everything in a varsol bath and blowing thru the bushings with compressed air, I reassembled the short shaft with a bit of lubricating oil, and it spins very freely.
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Next up will be the crankshaft. In the original plans, the crankshaft and rod journals were 0.281" (9/32") diameter, but I am blowing that up to 0.3125" (5/16) because I have reamers to suit that. The original plate crank-throws were .156" thick, but I am going to use 3/16" material, because I want the added thickness to help hold the pressed together parts more securely. I don't anticipate a problem making all the individual components, but getting everything pressed together and still maintaining the alignment required may be a challenge. The cold rolled shafting I have measures at 0.3120 to 0.3125" diameter. My undersize reamer is supposed to make a hole 0.3110" diameter. Probably a .001" press fit will work okay, as these steam/air powered engines are not high revving engines and not torque monsters.
(http://imageshack.com/a/img924/8241/VdzNj5.jpg)
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This is how I plan on going about the pressed together crankshaft. The grey 3/16" plates are the crankshaft "throws". The blue shaft is a "sliding fit" through these two plates and it's only purpose is to keep the two center holes in the plates perfectly aligned. The red round shaft will be the con-rod journal, and it will be a "hard press fit with Loctite" into the two grey plates. The green part is a temporary spacer which will be an exact fit between the two grey plates, probably held in place with some hot glue from my glue gun. The purpose of the green spacer is to prevent any movement of the grey plates relative to the red con rod throw and each other, when I press the long portion of the main crankshaft through everything--a hard press fit. once the crankshaft is fully assembled, I will heat and remove the green spacer plate, and mill away the remaining piece of the long main crankshaft from between the two sets of "throw plates"
(http://imageshack.com/a/img924/9851/8Q35WH.jpg)
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I have to make 4 of these for my built up crankshaft. My first thought was to rough saw them out of 3/16" cold rolled plate as full circles, then use the double sided tape trick to stick them to the nose of my lathes 3 jaw chuck and turn the outside diameter to finished size. (The point on the live center in my tailstock holds them tight against the double sided tape) Then I would tack weld all 4 together and set them up in the 3 jaw chuck on my rotary table to drill and ream the center hole and the other hole in the milling machine. Then I realized that these plates are only 1.25" diameter, while the nose of my 3 jaw chuck was 1.8" diameter when the jaws were completely closed.--That won't work!! --So--On to my next trick--perhaps I can chuck up a solid piece of 1 1/4" cold rolled steel round-stock in the 3 jaw chuck on my rotary table, drill and ream the two holes to at least 1 1/4" deep with my milling machine, (It is critical that the 0.375" center to center is held very exactly and that the reamed holes be perfectly parallel to the center axis of the round stock), and then move the material over to the lathe and part off 4 "slices" 3/16" thick. That works, but it will be an interrupted cut, and I never get a spectacular finish on the face of things I part off. Of course I can take a facing cut on the exposed side before each parting off operation, so the plates would have a good surface on at least one side. I'm still at the "thinking this through" stage. Material is cheap, and my time if free.--But I still don't want to have to make these more than once. The thought of machining this somewhat flimsy crankshaft from one solid piece of steel makes me quiver all over---
(http://imageshack.com/a/img922/3668/gJfXcZ.jpg)
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Brian,
I have to say that I would have the opposite problem. I don't even like the idea of a built up crank and would be trying to figure out how can I avoid a built up crank. Despite the fact I've seen very accomplished engine builders do built up cranks the idea it could fail and take everything else with it makes me nervous.
Art
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Brian, why not part off the first one a little over thickness, face remaining stock, part off next one over thickness, etc. When you have 4 slices change to 4 jaw and face then to finished thickness.
Alternatively saw off each one after facing the end which will mean less material is needed = shorter reamed hole.
Could also cut them from flat bar, then mount on an arbor to turn them round then mill to triangular shape.
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Brian,
I am following your crank build closely as I may have to re-make my crank as it isn't as true as i would really like it. If you have a press fit of the journals, will the Loctite be of any value?
Robert
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Okay--Here we go. Crankshaft step #1. A piece of 1 1/4" cold rolled round stock in the three jaw chuck, the end faced, and the center hole drilled 1.7" deep and reamed to 0.311 diameter.
(http://imageshack.com/a/img923/7500/v78vnw.jpg)
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Brian,
I am following your crank build closely as I may have to re-make my crank as it isn't as true as i would really like it. If you have a press fit of the journals, will the Loctite be of any value?
Robert
Loctite will work even with a press fit. Loctite rep. says that Loctite will always work. It will fill pockets even at the microscopic level.
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It doesn't show up really well, but this is the second step in my crankshaft build. After cutting off the 12" length of 1 1/4" cold rolled to about 3" long, I set it up vertically in the three jaw chuck on my rotary table. Then I picked up the center, and moved the mill table exactly 0.375", then drilled and reamed the second hole to 0.311" diameter. Now it has crossed my mind that if I wanted to, I could mount the rotary table on it's other face and mill the two flats on the crankshaft webs---but--I think I will have enough headache parting of slices of this round part because of the interrupted cut caused by the second off-center hole. I don't need the added interrupted cuts that would result from milling those flats now. I will get to that later in the process.
(http://imageshack.com/a/img922/1305/AtS658.jpg)
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So---With much butt clenching and clackety-clackety-clackety, I successfully parted off four discs on my lathe which are destined to become crankshaft webs. I have a 3 mm wide inserted carbide parting off blade that is worth it's weight in gold. One hand on the squirt oilcan full of cutting oil, the other hand on the lever that kicks the cross-feed out of gear if anything horrible happens. I love the power cross-feed, but it terrifies me.
(http://imageshack.com/a/img924/5437/9k6I6o.jpg)
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I have everything ready for pressing together. That web on the extreme left is just a brass "pattern" that was made up to be able to accurately scribe the cut lines on the 4 steel webs.
(http://imageshack.com/a/img922/4465/h0hE2G.jpg)
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When you press fit a crankshaft together with Loctite, the Loctite actually acts as a lubricant--but---Ya don't have time to stop and take many measurements or adjustments. Once things start to move, you want as much as possible to keep it moving with no stops until you have reached the "home" position. Those three pieces of aluminum with the open slots in them are "spacers". Two represent the 5/16" between the web plates and one represents the space between the two sets of web plates.
(http://imageshack.com/a/img924/6914/tYeOug.jpg)
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All I have left to do is the final trimming and pressing and cleanup. So far, so good.
(http://imageshack.com/a/img922/3867/brzMUA.jpg)
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Looking real good Brian. Are the journals going to be 90 degrees or at 180 degrees?
Thomas
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I want the engine to self start, so the journals will be at 90 degrees. The engine would run at 180 degrees, but the engine would not self start then.---Brian
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Very nice indeed Brian.
Robert
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Other than a bit of cleanup work, the crankshaft is finished. It fits where it is supposed to, goes round and round without smacking into anything, and is reasonably straight. I have found that these crankshafts for double or triple cylinder engines share a lot of characteristics with a wet noodle. When everything was first pressed together, without the main crank sections being cut out, I set one end up in the three jaw chuck on my lathe, right up to the first web plate, and put a dial indicator on the extreme outboard end. It had 0.135" total runout. After the main crankshaft was cut out from between the web plates, I stuck it back in the lathe and it measured 0.060" total runout. Then it was simply a matter of light smacks on the outboard end with a soft faced hammer, and chasing the high spot around until I got it down to about 0.008" total indicated runout. I went across town today to my tool shop, and bought a 1/16" straight flute reamer and the appropriate drill to go with it. I may drill and pin the web plates to both the main crankshaft and the con-rod journals. I have to think about that one overnight. After I was finished in the lathe, I installed the crankshaft in the engine with the bearing hold down bolts loose, gave it a few spins just to be absolutely certain that it didn't hit anything when turned thru 360 degrees, then tightened down all the bearing bolts. The Loctite I used takes about 20 hours to completely "set up". I would prefer that it "sets up" with the crankshaft in the position it will occupy, rather than just setting out on the bench. I ended up using 5/16" drill rod for the crankshaft, not because it is "better" than cold rolled steel, but because cold rolled steel shafting comes in about .0005" undersize, and I wanted more interference fit than plain cold rolled would give me. Drill rod comes in "full size", and that extra .0005" on the diameter gave me a much better press fit. I used my 2 ton manual arbor press, and had to put a 3 foot long pipe on the handle to give it enough "grunt" to press everything together.
(http://imageshack.com/a/img923/1479/gcgLOw.jpg)
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Nice work and well documented Brian. Thank you for detailing......Terry
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I got up this morning and drilled/dowelled the crankshaft webs to the main crank and to the rod journals. I don't think that in a million years this engine would create enough torque to make this absolutely necessary, but it only took an hour of my time and it gives me the feeling of a bit more security. I guess the next thing up will be the connecting rods.
(http://imageshack.com/a/img924/4245/1aYKul.jpg)
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Always good to have both belt and suspenders, maybe some extra rope too...!
:popcorn:
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Chris--Thank you for stopping by and having a look. Hind sight being 20/20, if I was designing this engine from scratch, I would have made the base longer, in order to allow thicker crankshaft webs. I would suggest that for engines using built up crankshafts, the design should allow for web plates at least as thick as the crankshaft diameter.
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I decided to do something easy this afternoon. My flywheel is going to be a two part assembly with an aluminum center and a cast iron outer rim. I save all my short ends of stock, and keep using them until there is nothing left to hang onto with my chuck. That lump of cast iron just to the right of the crankshaft is going to become the flywheel outer rim.
(http://imageshack.com/a/img922/925/5ENmad.jpg)
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I would just love to be doing some more with this project right now, but the pain in my back and right leg is just so ferocious I can't. All I can really do is lay around on my heating pad and take the Oxycodone pain pills my doctor has prescribed. I have a raging case of Sciatica that is still raging after two weeks. I have also developed something called "drop-foot" in my right foot, which is associated with the sciatica, and I'm walking a bit like "Lurch" of the Addams family. Getting old is not for sissies!!!
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Sorry to hear you are having a bit of a bad run health wise Brian, I am following your build closely as your engine is quite similar to the boat engine I built some time ago but not really totally happy with it. Is it OK for me to PM you with a few questions mainly regarding the crank shaft?
Robert
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Robert--By all means, contact me. I will be glad to help in any way I can.--Brian
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I seem to have worked my way through the greatest part of the pain, with the help of physiotherapy, Oxycodone, and time. I am still feeling a bit fragile around the base of my spine, but at least I've quit hurting. I really don't know what caused this flare up of Sciatica, but it was either using a different computer chair, or standing too long at my lathe. Whatever it was, thank God it's gone. I am not going to be machining anything until at least mid October, because I want to make sure this is totally cleared up before I do anything that might cause it to come back. In the meantime I will take all of the solid models I downloaded them from Grabcad and convert them to 2D dimensioned drawings so I will have something to work from when I do start machining again.---Brian
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I couldn't stand being idle any longer, so--This morning I turned the final outside diameter on that short end of cast iron that was in my lathe, faced the outer face, and bored it for a "push fit" of the aluminum center into it. Coated the outside of the aluminum center with 638 Loctite, and pushed it into place. (a "push fit" is half way between "get the hammer fit" and "Oh damn, it falls through fit").
(http://imageshack.com/a/img924/5871/3siSxT.jpg)
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Glad to see you back in the shop Brian, hope you get back to full steam ahead real soon. Your project is looking real good.
Thomas
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Brian, following along. Enjoy others build threads.
I had the phantom leg pains once. Have had slippage in the back some time but got it bad arm wrestling a man half my size ?
The neighbor brought over a small stool and told me to put one foot on it at a time as I worked. Wether running the lathe or working at the bench. Waalaa, away went the sciatic pains . Rememeber they are just pinched nurves. The stool took away the tweak in my bones. I keep a stool around if I ever stand in one place too long.
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I am past the worst of the pain, but the bottom of my spine just above my pelvis feels very fragile. Feels a bit like the big screw that holds my legs on has worked loose!! I am taking things easy waiting for this to clear up.---Brian
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I know how you're feeling, Brian. When your happiness and well-being depend on being able to get up and do things it's tough when physical ailments limit your movement. You can only exercise the mind so much, then you need to connect it to your hands and make things, and in our hobby, that means standing and walking around!
Chuck
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My, but there is a world of set-up work in these con rods. By the time I'm done with two of these things, I'll be qualified to start machining ear-rings for my wife!!
(http://imageshack.com/a/img923/8440/fFxxe8.jpg)
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I'm now into "second set-up" with the con-rods, machining the other side. Same fixture, but with a spacer washer of appropriate thickness between the finished big end boss and the fixture. The fixture is very handy for this kind of work. I know it doesn't look terribly different from the previous picture. After this operation is performed on both rods, then I have only to round the small ends and do a little "clean up" with my jewellers files.
(http://imageshack.com/a/img923/2313/AaTWtI.jpg)
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Brian
For some reason I am unable to PM you, tried several times (I am sure the problem is at my end) May I request you PM me with an email address?
Robert
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Robert--I just sent you an email.---Brian
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Today I finished the con rods. They turned out quite well. No, it isn't your eyes, that gudgeon pin hole in one of the rods is off center a bit. It won't affect how the con rod works, and if it is hugely visible when everything is assembled, I may make a replacement. It has burned about 8 hours of my time making these two.
(http://imageshack.com/a/img923/8061/pRdvPk.jpg)
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Okay--I have to say it--I'm stoked!!! It has been a long and busy day, but the first stage of assembly has been a great success. I completed the cross heads and "dummied up" a set of cross pins to connect the cross-heads to the connecting rods. I completed the bottom ends of the cylinders, with an integrated "guide/seal" on the underside to guide and seal the piston rod. Everything rotates and clears everything else. The engine is still a bit stiff, that is why the big V pulley is there. It lets me rotate the engine carefully and slowly by hand to check for clearance issues. The little 2" flywheel doesn't give me enough mechanical advantage to do this comfortably. Tomorrow, I will machine the pistons and piston rods, and try to get a video up showing the operation of the assembled parts so far.
(http://imageshack.com/a/img922/763/TbFL6J.jpg)
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Bob--I did send you an email, but I'm not sure whether you received it or not. At any rate, here it is copied and pasted.---Brian
Hi Bob—Every time I make a crankshaft, it’s a new experience. Yes, “drill rod” is what is called “silver steel” in other parts of the world. I don’t really think it is any better for crankshafts than ordinary cold rolled steel, but the fact that it comes in at “full size” instead of 0.0005” undersize (like cold rolled steel) is the reason I have used it in “built up” crankshafts.—However—that may change. This most recent crankshaft I made was a full 0.0015” interference (my undersized reamers are 0.0015” under ) and it was just too hard a press. Next built up crankshaft will be made with cold rolled steel which is 0.0005” undersize, so will only have a 0.001 interference. As I said, these built up crankshafts with thin web plates are very, very flexible. A crankshaft with thicker web plates would give a lot more guiding surface to the round rod pressed into it, and would be much less flexible. I don’t leave any clearance for Loctite. I think that is an old wives tale. If you only have .012” runout in your current crankshaft, put one end in the lathe chuck , use a dial indicator on the other end, and whack the high side with a rubber hammer. You will be amazed at how much these things will move. If I can be of any more help, email me.
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Hey Brian, that is just plain beautiful. All that hard work is showing up now.
Have a great day,
Thomas
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Today we're going to change things up a bit from the original Stuart engine. The piston will have one 1/16" diameter Viton o-ring. The piston rod is going to increase from 0.156" dia. up to .188" diameter (because I have a ton of 3/16" cold rolled), and there will be no threads at either end. The piston rod will be fitted into reamed holes in both piston and cross head and silver soldered in place. Of course this means that the bottom cylinder cover must be finished and placed on the piston rod before the ends are soldered in place, as it can not be installed afterwards.
(http://imageshack.com/a/img924/202/xeVD8c.jpg)
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Brian have you left the stuffing gland off as you won't be able to fit that either once soldered.
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I find that I have trouble with alignment on parts assembled with small diameter short threads. A reamed hole ensures my alignment. There is no gland nut on the bottom of the cylinder plate, as this engine will be ran on compressed air, not steam. A reamed fit and a bit of oil gives all the sealing required. There will be no heat, so I'm not worried about differential expansion factors.---Brian
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It was just that I had seen them on your previous drawings and did not want you to solder the parts with out the gland.
Interesting that you say a reamed hole and oil gives all the sealing required but you have done away with the oil grooves which are on the piston and added a seal in the form of an O ring :headscratch:
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I got crazy last year when I heard that my local o-ring supplier was going to stop selling onesies and twosies and only sell large batch lots to major companies. I went over and quickly bought 24 of 3/4" size, 24 of 7/8" size, and 24 of 1" size O-rings.--So--I had the Viton O-rings on hand. The engine would have worked equally as good as originally designed with simply oil grooves on the piston, no rings. I have half a dozen engines I built that run on compressed air and they only have oil grooves on the piston, no rings, and no stuffing boxes. One other factor that influenced the use of an o-ring on this engine, is that there are a lot of parts that have to line up "dead nuts" for the engine not to bind severely. I gave a little more than my usual clearance between the piston and cylinder to free up some of this potential "bind", and the o-ring means the engine will still have good "compression" even though the piston is not super snug in the cylinder.
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As I promised, here is a YouTube video of the engine to date, and a top view, showing the soldered piston to piston rod connection. I noticed after watching the video that I called the pistons --cylinders, so be forewarned.
https://www.youtube.com/watch?v=9_35ADjGqSM
(http://imageshack.com/a/img923/8334/RHFBBd.jpg) (https://www.youtube.com/edit?video_id=9_35ADjGqSM&feature=em-upload_owner)
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Brian, that youtube link appears to be to your upload page, not the video itself? Clicking on it takes me to my upload page...
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[youtube1]https://www.youtube.com/watch?v=9_35ADjGqSM[/youtube1]
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Final "running in" with all moving parts installed. Please let me know if this link works.
https://www.youtube.com/watch?v=16cjuCpjus8
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Final "running in" with all moving parts installed. Please let me know if this link works.
https://www.youtube.com/watch?v=16cjuCpjus8
Hey Brian,
The video loaded OK for me and all the parts look real good in motion.
Thomas
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it seems to me heroic to mount the parts without leaving a possibility of dismantling!
I would prefer to keep the possibitity to dismantle and or adjust length a little bit, as some joint or sealant stuff are not always of constant dimensions when pressed between cover and cylinder for instance.
I usually put the piston rod in the piston half way in a bored hole( I do have boring tool for 4mm hole) and the other half being taped, hence the rod is centered and fixed, and can be unscrewed !
on larger engine, the piston rod is coned, and a little nut on the other side, just like tooling...
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Today was a day for making cylinders. I made the end-caps yesterday. My back is sore and I'm going to quit for the day now. I am about half finished with the two cylinders (They are both hiding in that piece of stock in the mill vice.) For something as small as they are, they certainly have a lot of work in them.
(http://imageshack.com/a/img922/7519/ZnsGpe.jpg)
(http://imageshack.com/a/img924/5703/y06g89.jpg)
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Zephyrin--Just because I do it doesn't mean it's the right way. And it isn't really that bold. Anything I can assemble with my torch and silver solder can be just as quickly disassembled with the torch.
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Making cylinders isn't that difficult--but it's tedious. I had great plans of finishing both cylinders today, but "real work" interfered. So, after a day in my office across town, I don't have a lot of energy left. I did manage to cut the bar of 1 1/2" square brass into 3 pieces, face the cylinders to the correct length, and then I kinda run out of gas. It happens when you're 71!! And just for giggles--That piece of brass 3" long cost me $27. $12 for the material, and $17 cutting charge. Looks like I'll be at my office again tomorrow, but Saturday should get the cylinders close to being finished.
(http://imageshack.com/a/img922/7311/TTfyhg.jpg)
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Brian,
Still following along, Maybe some day I'll build a steam engine. Before the MEM Coreless one. :ROFL:
Art
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Nice movement Brian, the project is rolling along well. :ThumbsUp:(I did receive your email re the crankshaft and responded to it. Maybe there is some issues with the email system at the moment)
Robert
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You know, I thought after I shut my computer off last night that I might have screwed up the math in that post. Ah well, bad on me. It was $12 for the brass and $15 for the cutting charge. I haven't been posting many set-ups, because they really aren't all that exciting. Just very simple 3 jaw and 4 jaw work in the lathe and the mill vice. if I get into any set-ups I consider "special" I will take a picture of it.---Brian
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People have asked for more set-up pictures, so here we go. First picture shows drilling of holes for tapping in the end of the cylinder which was not exposed until the square bar of brass was separated into three pieces.
Second picture shows the wonderful versatility of my "tilt-a-whirl" mill vice, set up to the correct angle for drilling the steam passage at 21 degrees, and the third pictures show the final set-up for a 1/4" endmill plunged .062" deep so the newly cut steam passage is uncovered to the inside of the cylinder when everything is assembled.
(http://imageshack.com/a/img924/5871/YfTzXc.jpg)
(http://imageshack.com/a/img923/6825/Kwnu5W.jpg)
(https://imagizer.imageshack.us/v2/659x494q90/r/922/4I6Xse.jpg)
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These are the final steps before I set the cylinders up on an arbor and finish the outside surfaces. Picture #1 shows a set-up in the milling machine where the sloping sides of the cylinders which will show are machined to final size. Picture #2 shows the corners cut away on the bandsaw. next step will be setting the cylinders up on an arbor to finish the o.d. in my milling machine.
(http://imageshack.com/a/img922/4161/5Yj44I.jpg)
(http://imageshack.com/a/img922/4900/o6LCAF.jpg)
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A simple arbor made from 3/4" cold rolled (same as bore of cylinder) and a piece of scrap aluminum cross doweled to the end of it, gives me a fixture which I can mount a cylinder on, and use two of the tapped holes in one end to bolt it to my simple fixture. I then hold the end of the 3/4" cold rolled in my rotary table horizontally and use an end mill to cut the outer rounded profile of the cylinder.
(http://imageshack.com/a/img924/7043/bGqvG2.jpg)
(http://imageshack.com/a/img923/582/tsgV9N.jpg)
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And that, my friend is how we end up with this truly beautiful shape. The milling cutter is set at a fixed height. The table-stops on the front of the mill bed are set so as to prevent me running the cutter into the chuck jaws, or too far (needlessly) in the other direction. The cutter is centered over the rotary table chuck in the x axis and locked there. So--back and forth with the mill table in the z axis what seems like a million times, advancing the rotary table 2 degrees between each pass from right to left.
(http://imageshack.com/a/img922/4251/OKV56a.jpg)
(http://imageshack.com/a/img923/6074/0WfH92.jpg)
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Very nice work Brian.
Thomas
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Not finished yet but---You know how it is. You reach a stage where you have all these little pieces, and your just dying to see if they all fit together. Fortunately, they do. I had to speak rather harshly to the piston closest to the flywheel. Somehow, it was half a thou over 0.750 instead of half a thou under. I removed the Viton O-rings and tickled it a little with some 220 grit sanding strips, and then it decided it really would go into the cylinder anyhow. I have to "relieve" a bit of material off the two sides of the cylinders where they touch in the center, but that will be easy enough with my big stationary sanding belt. All in all, I'm very pleased so far.
(http://imageshack.com/a/img922/1115/IjEE8U.jpg)
(http://imageshack.com/a/img922/268/uu7De0.jpg)
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Excellent Brian, I love the technique of making the cylinders and they do look great. :D :ThumbsUp:
Will you be adding anything to the outside of the cylinders?
Robert
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No Robert--As this engine will run on compressed air and not steam, I am not worried about "heat loss" at the cylinders. I will polish the brass pieces and leave it at that.---Brian
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This will be the final "run in" of the engine, to let the pistons get well acquainted with the new cylinders. There is more information in the text part of the youtube video. That scraping noise you hear in the video isn't the engine. It's the side of that rather wonky big v-pulley scraping on the side of the workbench.
https://www.youtube.com/watch?v=UCVN3yoxvV0&feature=youtu.be (https://www.youtube.com/watch?v=UCVN3yoxvV0&feature=youtu.be)
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So you are hopefull that the valves and eccentrics will all be free running straight off the machines?
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Yes. Hopeful---
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Here we are turning the ends of a steam chest between centers. One center is held in the 3 jaw chuck, one held in the tailstock chuck with a bit of grease on the tip to keep it from getting hot or burning off. The lathe dog is a machinists clamp with a 1/4" bolt screwed into the side of one jaw to transmit torque from the 3 jaw to the steam chest.
(http://imageshack.com/a/img923/6034/pvGYKU.jpg)
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What a cracking little engine, and beautifully made too. ...Following with interest :popcorn: Terry
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The steam chests are still "in process". One is about 80% finished and is bolted in it's final position on the cylinder. The other steam chest is "Hot off the lathe" and I left the machinists clamp on it so you can get a better idea of how the 1/4" bolt screwed into one of the legs becomes the "drive dog" when it is set up in the lathe. The longest 5/16" diameter end will only be about 0.3" long when it is finished, but I have left it longer so I can grip it in my 3 jaw chuck on the lathe for when I go to put in the bore for the valve actuator linkage,
(http://imageshack.com/a/img924/8/Ep2K6Z.jpg)
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Today I discovered the first error in the 3d cad model of this engine which I downloaded from GrabCad. The hole in the end of the steamchest where the rod enters is shown as being .093" diameter, instead of the .125" diameter which is necessary to get the rod thru the hole. Not a big deal, and caught before I actually put the hole in. Easy to correct. Whoever made this 3D model has done a terrific job on it. I'm wondering--If the hole in the gland nut is 0.125" diameter, should I perhaps open the hole a couple of thou. larger in the steamchest entrance? I have never had a lot of luck putting two holes in parts that thread together and expecting them to line up perfectly.
(http://imageshack.com/a/img923/1738/WyQliI.jpg)
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On holes like that, where I am using a o-ring for the packing, I normally make the holes in both the steam chest and the packing nut a little over-size, runs much freer that way, and the ring does the sealing.
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Good idea, Crueby. I hadn't even thought of using an o-ring for packing. How much oversize do you make the holes?--About 0.010"?
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Good idea, Crueby. I hadn't even thought of using an o-ring for packing. How much oversize do you make the holes?--About 0.010"?
Yeah, whatever the next drill size about that much bigger is. If you use a twist drill to make the packing opening rather than a boring bar, then the bottom of the hole is already tapered, which pushes the o-ring against the rod and faces nicely too.
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My drills go up in 0.015" increments. And that second steam chest marks the last of the "big" pieces. I still have a whole bunch of "little pieces" to make, but this has come together nicely and is starting to look like an engine.
(http://imageshack.com/a/img924/7136/MLyMqA.jpg)
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Hi Brian
Not being saying much but following along, coming along nicely! On the tail hole in the valve chest, it’s likely the 0.093 is correct, the valve nut is threaded so the tail end needs to be the root diameter of the thread so that it’s smooth for going in the support, also suggest that you put a flat, doesn’t need to be very big, along the top so it doesn’t turn into a piston & can relive any pressure from the blind hole.
Jo covered the how to on the valve chest nut issue, pretty much put the nut in the valve chest & finish them together......sure Jo will correct me if I’m wrong, quite likely as I’m doing a bunch of night shifts.
Cheers Kerrin
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I usually ream the chest and nut on size eg 0.125" as the stainless stock for the valve rod is seldom spot on size and usually a thou or two below. If you think you will have problems with getting the two holes lined up cut the male thread on the gland nut a little deeper by tightening your die which will allow it a bit of lateral movement.
Even though you are running on air I would still put a small flat on the 3/32" end of the rod to avoid hydralic lock which you could still get with oil or a buildup of condensate from the compressor if you don't have a moisture trap.
Your nut should also have clearance to the bottom of the slot in the valve so the valve can lift off the portface slightly. Again more a steam thing but people may well build from your drawings and want to run on steam.
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I ended up reaming the .093" hole in the steam chest for the cantilevered end of the valve rod, and drilling the 1/8" hole where the rod enters. The fact that I drilled the 1/8" hole instead of reaming it gives a little "slop" which should prevent the valve rod from binding after I have added the packing nut. That valve rod is a full 1/8" diameter right up thru the valve nut, then it reduces to .093" for the last half inch or so.
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Today I finished the steam chests and made eccentrics. I liked it so much, I made them twice.---Didn't plan it that way, but after I got the first two parted off I realized that I had no way to hold the friggin' things to put that groove in the center.---Big Headslap!!!
First step was to put the material in the 3 jaw chuck on my rotary table, center it under the quill on the mill, then dial in the offsets and drill/ream the large hole and drill the 1/16" hole about 1" deep from the end. Then over to the lathe and part them off.--Then curse and repeat--only this time put that groove in before parting off.
These are the "simple" eccentrics. There are another pair, slightly more complex that I will make tomorrow.
(http://imageshack.com/a/img923/8669/b5pkDp.jpg)
(http://imageshack.com/a/img922/3627/OnDyoA.jpg)
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All four eccentrics are finished. Not nearly as much drama with the second set of eccentrics--I knew what to watch out for. Normally, a steam engine has only one single eccentric per cylinder. This one has two per cylinder because of the Stephensons reversing linkage.
(http://imageshack.com/a/img924/1404/MauzYk.jpg)
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:popcorn:
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That's enough playing for today. Just finished the steamchest covers. I have to go talk to another old customer who has just contacted me.--And that's okay. My back is starting to bark at me anyways.
(http://imageshack.com/a/img924/3170/Pe3ycA.jpg)
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Out of curiosity, I wanted to have some idea of the force that would be exerted on the pistons by the compressed air I will be using. At 60 psi, each piston will exert about 26 pounds of linear thrust. With a 3/8" crank offset (half of the 3/4" stroke) that rounds out at about 9.75 inch pounds of torque. If I consider that I have two pistons operating on a 90 degree crankshaft, I can't double that 9.75 inch pounds, but I should be able to use a 1.5 multiplier, so about 14.6 inch pounds of torque. This converts to 1.2 foot pounds of torque. So--If I hang a 1.2 pound weight 12" away from the center of the crankshaft and the crankshaft doesn't rotate, I'm in trouble.
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Remember that the 3/8" offset for leverage only applies at the point where the crank is at 90 degrees to the piston, for the rest of the travel the offset is less, tapering to zero at TDC and BDC. Also, that assumes that your valve and passages are admitting enough flow of air to keep that PSI inside the piston chamber. The real output will likely be a fiar bit less than you are calculating.
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Crueby---I know what your saying. However, with a Viton ring on the piston and gaskets on both end of the cylinder and on the steamchest, it will probably hold the pressure. Right now it's pure conjecture anyways. I was curious, so I ran the math. I am a long ways from trying to run the engine at this point, but it is getting kind of exciting.
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I think you are worrying over nothing, my single cyl D10 runs on 5psi or less and it was never motored for hours to loosen it up before trying on air.
Also once it starts turning you have the momentum of the flywheel to figure into your calculations.
[youtube1]https://www.youtube.com/watch?v=lHUTsC2eknA[/youtube1]
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I have two really dreadful pieces of bronze left over from that 50 pound weight that found it's way to my house. It made a lot of beautiful flywheels, and now I'm using the left over scraps. These two pieces are destined to become the reversing shaft brackets which hang of the face of the steamchest covers.
(https://imagizer.imageshack.us/v2/800x600q90/r/924/eMUCuk.jpg)
(http://imageshack.com/a/img924/2826/gZlaoO.jpg)
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The pieces are laid out and the rectangular profile I require is cut free, leaving about .031" all around the perimeter greater than the finished size I will need.
(http://imageshack.com/a/img924/8395/3W6W6u.jpg)
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The rectangular pieces are held in my mill vice and brought down to finished thickness, and all holes are drilled.
(http://imageshack.com/a/img922/5163/Qyx0ml.jpg)
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The rectangular pieces are sawed/filed/sanded to their final shape, and a simple fixture made up so I can mount them in the lathe to turn material away from both sides, to expose the "boss" on each side.
(http://imageshack.com/a/img922/997/Ytsid1.jpg)
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The fixture is mounted in the 3 jaw chuck in my lathe, and first one side is turned, then the other on both brackets, exposing the boss on each side.
(http://imageshack.com/a/img922/5928/RZ18sx.jpg)
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And here we have the two reversing shaft brackets installed, with the reversing shaft setting in them.
(http://imageshack.com/a/img923/157/DIqd3i.jpg)
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The eccentric strap on the original Stuart models (shown in yellow) is very pretty, but difficult to make as it looks like it will require a lot of rotary table work on the outer perimeter. I have redesigned it so that it requires no rotary table work. It is made in two stages--first with definite corners on the left hand side, then mounted on a mandrel and the corners knocked down with a file. The end result looks fine, and requires no rotary table work at all.
(http://imageshack.com/a/img922/3334/xxupVc.jpg)
(http://imageshack.com/a/img923/74/33ievB.jpg)
(http://imageshack.com/a/img923/1814/CMgxGc.jpg)
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:headscratch: What's difficult about using a rotary table? It will be quicker to mill the outer curved surface than mess around with trying to equalise the angles :noidea:
Jo
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Jo--I'm not enthused about the radial cranking it will take to make that shape. The straps are 0.219" thick, and I think about the maximum depth of cut I want to make with a small endmill is 0.020" That is 11 successively deeper cuts in three different places on four different pieces.
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I'm not really sure how this is going to turn out, but it's ,uhmmm---interesting. The shape is very definitely there. Now that the basic shape is there, it's time to transfer into the 4 jaw on my lathe to bore and ream the 5/8" hole, 2" deep.
Then if I'm lucky, I will part off four eccentric straps. I will do the tapped holes and sawcuts after all four straps are parted off.
(http://imageshack.com/a/img924/2783/Ru8ILn.jpg)
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Well--That didn't turn out to shabby!! I still have to part the four straps off from the parent stock, and add threaded holes and saw cuts. I'm happy with it. Now if I can part it off without any disasters, I'm almost ready to start sorting out linkages.--Disregard the 3D drawing it's setting on. That's a design job I'm working on for a customer.
(http://imageshack.com/a/img924/1694/KN6v33.jpg)
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This mornings work was to finish the eccentric straps. The long bolt represents the linkage which will extend up from the eccentric strap to the Stephensons reversing linkage. The clamp bolt at the sawcut allows tightening or loosening the fit of the strap to the eccentric itself, and the short bolt which you see extending into the bore fits into the slot in the eccentric to keep the strap from trying to fall of the eccentric as the engine runs.
(http://imageshack.com/a/img924/6617/kC0lQo.jpg)
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Jo--I'm not enthused about the radial cranking it will take to make that shape. The straps are 0.219" thick, and I think about the maximum depth of cut I want to make with a small endmill is 0.020" That is 11 successively deeper cuts in three different places on four different pieces.
The 5A straps I have just finished were 0.34" thick and I took 40 thou cuts with a 6mm cutter...
Jo
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This afternoon I made the gland nuts for the steamchests. I'm done for today. I had a couple of thoughts today.--#1 thought--I have this thing finished to the point where another days work could see it running without the Stephensons reversing linkage. #2thought---I think I need to tap the holes in the side of my steam chests, otherwise I have no way to attach the pressure lines to it.--May have to tap the exhaust holes in the sides of the cylinders.
(http://imageshack.com/a/img924/4279/CMFiJB.jpg)
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They are tapped on the Stuart version, alternative is two small tapped holes either side and use a flanged fitting.
You could actually have saved yourself a bit of work on the straps by having the end of the eccentric rod locate into the groove rather than a separate screw, Stuart used the screw as the rod and strap were a single casting. Also debatable if the slot is really needed as an engine that only runs a few times is unlikely to wear the straps
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Jason--I did a Google search for Stuart double 10's just after posting the previous, and I see that some steamchests were tapped and some had a small screw on each side of the air inlet to hold the flange in place. As far as the straps are concerned--you are probably right, but it wasn't a great deal more work to make them like the model I downloaded.
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Jason--I did a Google search for Stuart double 10's just after posting the previous, and I see that some steamchests were tapped and some had a small screw on each side of the air inlet to hold the flange in place. As far as the straps are concerned--you are probably right, but it wasn't a great deal more work to make them like the model I downloaded.
Went and checked my 35+ year old D10, it has both the chests and exhaust holes threaded.
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Thanks Crueby---I'm not quite as far along as I thought. I still have to make slide valves and valve nuts, gaskets, and an unseemly quantity of little brass ends that fit on all of the linkages, even for a simple runner without the Stephensons reversing linkage.--Brian
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I think the reason you are seeing both options on the net is that the Stuart drawings show the holes tapped 32tip which people do on their first engine and then when they want to get it running find that all the commercially available steam fittings in those diameters are 40tpi so have to make up flanges to change the thread.
Flanges also make it a bit easier to attach a long run of pipe with several bends that would be hard to screw straight into the castings.
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Today was the day for slide valves and slide valve nuts. I had a lot of trouble with the slide valves.--You know how it is---Measure wrong, cut too deep, launch part across room, solder short end to add piece back on--Maybe my mother was right about not working on Sundays. At any rate, I persevered and finished the parts.
(http://imageshack.com/a/img924/4843/S7jx7j.jpg)
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(http://imageshack.com/a/img923/3888/U1xDRl.jpg)
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If those pieces were threaded into each other they would be just like the pins used to hold knife scales onto the tang. Should work well.
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Yep, I agree with screwing it.... Someone may want to take that engine apart someday and might be a bit miffed at it being glued together.
Pete
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Anything that can be assembled with Loctite can be "disassembled" just as quickly with a bit of heat. That inner part is only 0.094" diameter. I don't even have taps or dies that small. BUT---Your posts show me that somebody's looking at my thread, and I surely do appreciate that. I don't get many answers on my threads, and sometimes I feel like I'm posting into a vacuum. Thanks guys, for stopping by and having a look.---Brian
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Anything that can be assembled with Loctite can be "disassembled" just as quickly with a bit of heat. That inner part is only 0.094" diameter. I don't even have taps or dies that small. BUT---Your posts show me that somebody's looking at my thread, and I surely do appreciate that. I don't get many answers on my threads, and sometimes I feel like I'm posting into a vacuum. Thanks guys, for stopping by and having a look.---Brian
May not chime in a lot, but am a regular reader!
:popcorn:
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Brian, I follow all of your posts and look forward to them. I didn't twig to that pin being so small.... the drawing makes it look bigger!
Pete
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If you are worried about the screw in pin backing out why not loctite it in place, no different to loctiting your two bits together. Or make it with a longer thread and fit a small locknut
Other easy option is a 5/32" pin with a 3/16 or 7/32" head on it and drill the other end for a 1/32" split pin (Cotter in think you call them)
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Hi Brian, I am another regular reader who reads all your posts. I will try and lift my game and reply more often. I learn so much from your set up pictures, and from your designs, thank you.
MJM460
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Let me be the first to point out----I'm not really good at making these small clevises. When parts get this small, (1/4" square) I have a difficult time getting them to be cosmetically correct. The reamed thru holes are correct, and the #5-40 (1/8 dia.") threads are in the right place, but the overall outer shape always leave a bit to be desired. You will notice that I have made extra of each type. This lets me pick the best ones out of the lot and discard the really bad ones.
(http://imageshack.com/a/img924/9242/q5DyuP.jpg)
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Hi Brian,
I do follow your posts, sometime only two or three times a week, so most of the time there is no point in me posting as someone else has raised the point. But this time I am wondering why you did not make the eccentrics sheave as a split unit bolted together? would be much easier to install, rather than having to spread the eccentric sheave over the eccentric.
Gerald.
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I'm doing a juggling act here between "real" paying design work and no pay engine building. I'm finding that I don't really want to give up any of my time for "real" work, and that's bad. I would give it up completely, but I know that 2 or 3 weeks down the road when this engine is finished, I'll be going mad for something to do. I finished all of the clevises that this engine requires, and tapped the ports in the side of the steamchest. I have finished securing the cross pin for my con-rod, and everything clears, but man, it's a tight fit inside those cross head guides. I've decided that before I finish the Stephenson's reversing gear, I will attempt to run this as a simple non reversing engine, then if I am successful I will add the reversing gear. All I have left to do now is make some connector links out of 1/8" diameter steel rod and to make some gaskets.
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Hi Brian,
I do follow your posts, sometime only two or three times a week, so most of the time there is no point in me posting as someone else has raised the point. But this time I am wondering why you did not make the eccentrics sheave as a split unit bolted together? would be much easier to install, rather than having to spread the eccentric sheave over the eccentric.
Gerald.
I'm not totally sure what you are asking me. My eccentric straps just slide endwise over the eccentrics. There is a very short bolt thru the bottom tapped hole to fit into the slot in the center of the eccentric and keep the band from slipping off. The 1/8" diameter steel linkage fits in the other tapped hole, and there is a squeeze bolt to adjust the tightness of the strap.
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Sometimes---Things get pretty damned crude around here. I wasn't having any luck at all turning the end of a 1/8" rod to .093" to fit into the blind end of the steamchest. So--Out comes the faithful pneumatic die grinder, and ground it to size. It worked. a little touch up with some sanding strip and we have one steamchest linkage finished.
(http://imageshack.com/a/img924/2066/sJ3Lvx.jpg)
(http://imageshack.com/a/img924/800/2OYqPp.jpg)
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Here we have the ultimate in "low tech" gasketry. Print the parts the gaskets are going onto at 1:1 scale, cut them out and use a glue stick to stick them onto a piece of .030" general purpose gasket from the automotive supplier in town. When the glue is dry I use scissors to cut the outer profiles, an exacto knife for the inner surfaces, and a leather punch for all the bolt holes.
(http://imageshack.com/a/img924/7974/zHVIpg.jpg)
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And, if you didn't know what a leather punch looks like--this is it. The handiest gasket hole maker you could ever think of. The engine is all reassembled now, complete with gaskets but two of the control links I made this afternoon appear to be to short on one end. Will correct that tomorrow.
(http://imageshack.com/a/img922/7412/4dbgnj.jpg)
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Yesterday, I made up all of the 1/8" threaded rods that transmit motion from the eccentric to the slide valve. On assembly, it became clear that I had made the rod attached to the eccentric strap too short. So, today another kick at the can. I'm not worried about valve timing yet. However, with the slide valve exactly at the center of it's travel in the steamchest, and the highest point on the eccentric lobe setting parallel to the engine base, that lets me measure from the top of the eccentric strap to the "eye" on the brass fitting attached to the slide valve rod. This measurement will let me determine the correct length for the rods I have to remake. The "throw" on the eccentric is only .093", so the total movement of the slide valve will only be 3/16" in total.
(http://imageshack.com/a/img922/6004/ld3j8o.jpg)
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Getting close to a test firing, looking great!
When you get to the reversing gear, the rod you are making now will be replaced to make room for the stephenson linkage, right? When you make that setup, it is vital that the distances from each eccentric up to the slide linkage slot is the same, otherwise timing is impossible to get right for both directions.
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Brian, you don't seem to have very much thread on the valve rods. A good length of thread allows for adjustment simply you turning the rod & clevis, a 5-40 thread will allow for 0.0125" per half turn. Unless your first set of rods were miles out this would have allowed for any small errors in length.
(http://img.photobucket.com/albums/v156/jasonballamy/Engineering/Tidman%20Organ%20Engine/Tid149_zpsyuxlx2zx.jpg)
(http://img.photobucket.com/albums/v156/jasonballamy/Engineering/PICT0339.jpg)
(http://img.photobucket.com/albums/v156/jasonballamy/Engineering/Cameron%20Steam%20Pump/IMAG3509_zpsbeef7d49.jpg)
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(http://img.photobucket.com/albums/v156/jasonballamy/Engineering/PICT0339.jpg)
Does that valve nut not close off the inlet port in mid position :noidea:
Jo
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Engine runs fine probably because there is no steam flowing when the valve is at the mid position anyway as the two inlet posts are closed see attached and nut is narrower than the diameter of the hole in the valve chest :ROFL:
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Brian, you don't seem to have very much thread on the valve rods. A good length of thread allows for adjustment simply you turning the rod & clevis, a 5-40 thread will allow for 0.0125" per half turn. Unless your first set of rods were miles out this would have allowed for any small errors in length.
(http://img.photobucket.com/albums/v156/jasonballamy/Engineering/Tidman%20Organ%20Engine/Tid149_zpsyuxlx2zx.jpg)
(http://img.photobucket.com/albums/v156/jasonballamy/Engineering/PICT0339.jpg)
(http://img.photobucket.com/albums/v156/jasonballamy/Engineering/Cameron%20Steam%20Pump/IMAG3509_zpsbeef7d49.jpg)
Do you think elongated 'rectangular' ports would offer any noticeable improvement over circular ones ? I'm no expert but I'd assume with a circular port the entry is opened gradually as the valve block approaches the port diameter but a milled rectangular port would have a more abrupt opening and closing effect ?
I'm not sure whether that is a good thing or not but I'd be interested in what others think.
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On our type of models we are not interested in efficiency etc and if the engine is not running you will turn up the pressure so no you will hardly notice anything.
However the most efficient full sized engines, like the Corliss, had very sharp cut off and the inlets/steam pipes were designed to maximise flow rate (i.e. minimise obstructions and the resultant effects of turbulence on the flow) to ensure that full volume/pressure was available to flow into/out of the cylinders whenever the valves opened.
The effects of flow rates are even more noticeable on Gas engines ;)
Jo
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Well all I can say is that the ones I have done with the round ports - Benson, Muncaster and Thompstone are some of my smoothest runners and will all run on a whisper of air pressure, my gauge does not start reading until 5psi and they all run with it on the stop.
As Jo says we don't really work them in which case there may be a difference but they are certainly efficient on air used which saves having the compressor running all the time so I should think they will be even better once you get your steam boiler hooked up to them :)
The other plus side is they are dead easy to make as there are no narrow slots to make and the depth can be more than a small milling cutter will reach so drilled passages can be straight rather than having to drill at an angle.
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Thanks, I guess I was just curious as it seems most castings seem to come as milled slots so I assumed there is a reason for it.
As for the boiler Jason, I collect it next Tuesday, so can't wait to start shovelling mucky coal into it ;D
Anyway - back on track, I don't want to hijack Brians build log :)
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My first set of linkages were 1/4" too short. Pretty hard to make that up with the threads . And right now I'm not even sure how that happened.--Jason--It is plain from your pictures that you are a far better machinist than I am. I do okay on the larger stuff, but when I get down to the little bits and pieces I find it difficult.
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I do okay on the larger stuff, but when I get down to the little bits and pieces I find it difficult.
Don't feel alone on that Brian! :old:
Pete
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JasonB :
I always admire your models, and the skill required to obtain these results... but as regards the shape of the steam ports, I did experimenting on this on 2 occasions with little steam engines (12 x 12 mm and 10 x 20 mm bore & stroke for the 2 engines), and as expected from theory, steam ports with straight edges greatly improved running, as the opening and closing of the steam port are much faster.
I agree that cutting rectangular steam port is not that easy, and small and flexible milling bit does not help with straight line !
I use a shop made cutter, a sort of miniature gang milling, cutting the 3 ports in the same time.
In fact, steam ports were made by drilling as usual, I simply change the shape of the ports with gang milling on the surface of the port face to improve steam distribution, my pet subject I confess, steam distribution is the point I really love in steam engine, even if nothing is visible from outside !
https://photos.app.goo.gl/6gHzxz0j1fdR6YNG3
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Hi Gas Mantle, I did some posts on the port shape issue in the Talking Thermodynamics thread. Have a look at the post on 5 July, and a few more around that time. It's actually the exhaust opening that is critical, but the ports are used for both inlet and exhaust and there is no harm to the inlet port.
Hi Zephyrin, those were interesting experiments, it's good to see the theory being borne out in practice, as otherwise there is always remaining doubt. You are right though, steam distribution is everything.
MJM460
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IT'S ALIIIIIVE---Right now I only have one cylinder hooked up and no packing in the valve glands, but the engine is up and running.--more to follow---
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As I set typing this, the engine is now running on the other cylinder. I like to run each cylinder individually before splitting the incoming air to drive both cylinders.
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Try this one to see the first run of the vertical twin engine.
https://www.youtube.com/watch?v=kYyiChGOYzI
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Not working for me Brian but good to know the engine is working.
EDIT, Video OK now
Zephyrin, in what way did the straight ports improove running? More efficient, powerful, etc?
J
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Congratulations Brian, nice to see your engine running...
I liked the way the gasket were cut, I certainly will do the same next time!
"automotive", you mean the kind of gasket with a layer of metal ?
JasonB :
I would say more efficient...more like a steam engine !
For instance, on a small 2 cylinder "marine" engine the AL5 of 12 x 12 mm bore & stroke,(a very popular model here amongst marine modellers), I did the port face according to the plan, ie a simple row of hole, that gave an engine that ran well, but unable to use the Stephenson linkage properly, if not for reversing the engine, no way to keep admission at low cut-off. When the port face were re-machined to give straight edged ports, it became a new engine, running easily at low cut-off, like a real one, just smaller, using all the properties of steam.
I agree that this is mainly academic, but as a steam buffs, this is my goal.
On many model running on compressed air at a low pace, where the steam distribution, often without lap and lead, is not designed to win races, this is without effect in short, and this will not deters me to admire these beautiful engines in the shows or read the threads on the forum !
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Looks to be a good runner Brian, well done :)
Have you thought about cutting a bit of detail on the upper surface of the base ? Something like the original Stuart engine here :-
http://www.stuartmodels.com/item/27/stuart-d10 (http://www.stuartmodels.com/item/27/stuart-d10)
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No more details added to the base. All that detail does is make more work for me and adds nothing to the way the engine runs. Automotive gasket is just a treated cardboard, no metal anywhere. The side from your Kellogs cornflakes box will work just as well.
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Now that things are well broken in, this is a video of my engine running at a much more sedate pace.
https://www.youtube.com/watch?v=OWqNR4U-WXc
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Brian,
Glad to see you have a runner. Insert happy dance here. :pinkelephant: I look forward to seeing the reversing linkage.
Art
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Very nice! It sounds like you have the timing dead on, nice even beat to it. :cartwheel:
For threading the small rod, I was having the same issue, till I found that if I use the 4-jaw independant chuck rather than the 3 jaw scroll chuck, it allowed me to grip it much tighter, getting rid of the tendancy to spin the part in the chuck. Also, for steel rod taking a few thou off the diameter before threading helps a lot, just like drilling a slightly larger hole for tapping in steel vs brass.
Looking forward to seeing it with the Stephenson linkage!!
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My problem was that the 5" lathe chuck will not close enough to hold a 1/8" diameter rod. My work around for that is the smaller chuck and arbor out of an electric drill. However, the smaller chuck isn't very strong. Yesterday I ordered up a much beefier industrial chuck that comes with an arbor and will hold from 5/8" down to 1/64" diameter. That should solve my problem.
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I can tell right now---there's going to be a lot of Voodoo in this 'expansion link' which seems to be the heart of the reversing mechanism--and I need two that are identical. Probably my best bet is to tack-weld two pieces of 1/8" plate together before starting to do any cutting or shaping. In fact, since I have a 3 jaw chuck mounted on my rotary table, it would probably be a good idea to attach a 3/4" round handle to the plates right at the center of the arc in the plates so that I can mount the rotary table with the central axis of the chuck vertical. The holes are not going to be a problem--I can use the DRO on the mill to locate and drill them. Cutting the arc shouldn't be a problem---in theory. The .078" radius on the ends of the arc dictates a 0.156" endmill, which I can buy locally. My rotary table has no "stops" that can be adjusted on the arc, so I see a lot of very meticulous angle watching because it will take repeated cuts all starting and stopping in exactly the same spot to cut that arc.
(http://imageshack.com/a/img924/7900/p3wm9M.jpg)
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Brian, the stephenson links are one of those items where it really pays off to take the hour to make a jig to hold the parts. There are a number of ways to do it, the way I did on my Lombard build worked well for me - it starts at post 1083 in that build log, basically I made a jig that fit on the rotary table with a post the size of the eccentrics at the center of the rotary table, and some cross-bar hold downs farther out. This one jig did the drilling for the eccentric straps, so they all were exactly the same length, and also milled the stephenson slider frames, so all the arcs were concentric to that same place. It made swapping between the parts very easy, one setup to cut all the pairs. With this kind of jig, no need to weld parts together and hope they come apart again when (and not till) you want.
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Thanks Chris--I just had a look, and that is exactly what I need to do.---Brian
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Wonderful running engine Brian. I too am one of those that looks in regularly but don't comment often. The reversing mechanism will add even more interest to the finished engine!!
Bill
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Bill--I'm just like the starship Enterprise---Going boldly where I've never gone before!!!I enjoy this, and I'm never real sure how it's going to turn out, but I'm having fun.---Brian
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When I have done them I just clamp a bit of gauge plate (ground flat stock) to the rorary table as it is more solid than using a chuck. Put a punch mark where where the arcs are all swung from and locate that under the spindle.
Drill out either end of the slot first, some people drill a fraction over, that way you can put on a cut when the tool is in open space rather than try and plunge down and have the tool deflect. Use 2-flute cutter for accurate width you may find a 4.0mm one more easily available.
(http://img.photobucket.com/albums/v156/jasonballamy/Fowler%20construction/expansion.jpg)
You can just see the larger end holes on the slot in this pic
(http://img.photobucket.com/albums/v156/jasonballamy/Fowler%20A7/PICT0110.jpg)
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I did my links for my Verticals here: http://www.modelenginemaker.com/index.php/topic,6912.msg158182.html#msg158182
Three of them and thanks to using the bit of scrap ali underneath and then drilling/tapping it to make a jig all are identical. I wouldn't want to risk doing two at the same time it is a bit deep for your small cutter to go.. you are likely to get an over width slot :facepalm2:
Don't forget to do the dies on the same jig ;)
Jo
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This is sorta/kinda what I had in mind. The green plate is 1/2" thick aluminum with a red 3/4" shaft 3" long hard press fitted to it. The red 3/4" shaft is held in the chuck jaws, The chuck is bolted to the top of my rotary table. The yellowish colored plate is 1/8" thick steel from which the finished link will be cut. Three #4-40 threads will be tapped in the 1/2" aluminum plate, and three "size on size" corresponding holes will be drilled thru the yellow coloured steel plate to hold it in place during the milling operation. The center of the red round part in the chuck is concentric to the center of the slot being cut in the link, and is centered under the mill quill. Since the rotary table will be locked until all of the holes are drilled, I can probably drill holes at the ends of the inside arc at the same time. Then when the rotary table is unlocked to begin cutting the arced slot, the drilled holes will tell me when to stop cutting at either end of the milled arc
(http://imageshack.com/a/img923/8594/qPlPLq.jpg)
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That looks like it will do the trick nicely Brian. Well worth the time to make the jig.
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why not just fit that jig plate directly to the rotary table?
make the shaft the same size as the center bore of the rotary table for alignment and then just clamp it down onto the table, would be more rigid and save some height
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Because it takes seven men and a bulldog to get that damned chuck centered on the rotary table!! It's held in place by 3 tee nuts with no center guide spigot.
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I'll turn the piece that sticks through to 5/8" diameter just in case I need to use the same set-up to set all of my eccentric strap assemblies to the same length. It also gives me something to center under the quill.
(http://imageshack.com/a/img924/1233/AKFqgI.jpg)
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It's Sunday night. I hurt my back yesterday, so I'm not up for much machining (until tomorrow at least.) I've spent today thinking about reversing gear, doing a bit of layout work, and yacking with my internet friends.--When I built this engine, I put Viton O-rings on the pistons. One ring per cylinder. All of the other "steam-engines" I've built, about a dozen, never had any rings at all---Just two or three very shallow grooves around their circumference for oil retention. They all spin very freely, and I never noticed any of them having a problem with pressure "blowing by" the pistons. With this engine I just finished, I was expecting some binding as all the pieces were firmly bolted together, so my reasoning was that if I leave a little more clearance between the steel piston and the brass cylinder, there would be less chance of the piston scoring the inside of the cylinder. The Viton ring would ensure no leakage of air, even though the piston wasn't as tight a fit as on my earlier "steam engines". A 1/16" cross section Viton ring is actually about 0.070" in cross section. I made the groove in the piston 0.060" deep, which is about .003" more than I do on my internal combustion engines. Everything works, just as I had planned. What I didn't plan, is the amount of drag that Viton ring would create. I know this engine should run easily on about 5 psi.---it doesn't. I have ran it for about 6 hours now, and it isn't going to wear in anymore than it has already. 10 psi is about as low as I can turn my air regulator without the engine stalling out. And---When the engine sets for a while, not running, the Viton takes a "set" and is a real pig to get the crankshaft rotating again. Soon as the crankshaft rotates even a little bit that "set" goes away, but it never goes totally away. I'm not going to change things now, but I just thought I would post this as information.---Brian
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I often make piston rings from graphite string covered in oil, it sounds a bit amateurish but with a bit of trial and error you can get a good air / steam tight fit that slides freely.
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O-rings want lubrication...
Pete
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O-rings want lubrication...
Pete
And in these uses less than 10% compression, I'd make the grooves .065"
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One picture of set-up and one of main slot milled. Lots and lots of breath holding and butt clenching going on!!!
(http://imageshack.com/a/img922/1599/K3F7qx.jpg)
(http://imageshack.com/a/img924/5339/9EpYNY.jpg)
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Second radial cut. Not as much breath holding this time, as I was able to use a 3/8" endmill. I'm running the mill at about 900 rpm, and cranking the rotary table slowly, cutting in both clockwise and counterclockwise direction. I advance the tool 0.010" each time I get to the end of a rotation. In a way part of this is climb milling, but a great deal more of the cut is endmilling.
(http://imageshack.com/a/img924/1158/XXmbcn.jpg)
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This is as much as I'm going to do today. There is more that I can chew away before tearing down this set-up, but this is as far as it's going today.
(http://imageshack.com/a/img924/7692/rbrthT.jpg)
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Thats a great start. The thing I like about that kind of setup is how easy it is to swap back and forth between the 2, 3, 4, however many, links being made at each cutting stage, and they all come out the same, all go back in to the bolts the same each time.
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In hindsight, I wish now that I had put both plates on my fixture and machined them both a once. Since I can only take about 0.010" depth of cut for fear of breaking my 0.156 endmill, it wouldn't have been a problem if I'd had both plates on there.---live and learn.
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In hindsight, I wish now that I had put both plates on my fixture and machined them both a once. Since I can only take about 0.010" depth of cut for fear of breaking my 0.156 endmill, it wouldn't have been a problem if I'd had both plates on there.---live and learn.
On mine, I just swapped parts between cuts, the 1/8" end mill did not have the length to go through both parts at once.
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In hindsight, I wish now that I had put both plates on my fixture and machined them both a once. Since I can only take about 0.010" depth of cut for fear of breaking my 0.156 endmill, it wouldn't have been a problem if I'd had both plates on there.---live and learn.
Using a Slot drill (two flutes) would have had less chance of breaking than an end mill (4 flutes). Cutting at the bottom of a deep slot would have increased the chance of breaking the cutter due to swarf jamming.
China does some very cheaply priced carbide slot drills available on Fleabay - I paid about £2 for one.
Jo
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I have reached the limit of what I can do in my milling set-up. The remainder of material to be removed will be done with bandsaw and file.
(http://imageshack.com/a/img922/3508/jCa9iM.jpg)
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So---we have one reversing link finished. All of the holes and centers of radii are exactly where they should be. The arc is exactly where it should be. Sid was right, cutting the 0.156" wide arc with a 0.156" endmill held in a drillchuck is not accurate---The slot ended up at 0.165" wide. This does not pose a problem for me, as I am the one who makes the "follower" that runs in the slot. When I do the second link, I will hold my 0.156" endmill in a collet and see if that yields anything different.
(http://imageshack.com/a/img923/5263/OeNOuD.jpg)
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The trouble with cutting a slot is the deflection of the cutter caused by asymmetric cutting forces. It can be mitigated to some extent by reducing the extension of the end mill, but better to cut down the middle of the slot with a .125 and then finish up the sides with a conventional cut.
--Tim
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For what it's worth---I cut the arced slot in the second part with my 0.156" four flute endmill held in a collet. The slot measures 0.161" wide. When I cut the slot in the first part with the same endmill held in a chuck, the slot came out at 0.165" wide.
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And now there ate two. Not nearly as much drama with the second one.
(http://imageshack.com/a/img924/5930/Wa3w1F.jpg)
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This is a very well done assembly video of the engine I am building. The reverse mechanism has a few minor differences, but the video is amazingly well done.
https://www.youtube.com/watch?v=M9r7gw-XxIc
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Okay, it's time to ask for an opinion. I am going to require a total of four eccentric strap assemblies. Two with straight rods connecting the ends and two on which the rods have a 1/4" offset. In the normal course of affairs, I would thread everything and screw all the pieces together. Although they look huge in this picture, they are only 1.646" center to center. I have a fixture to mount everything on at the exact centers required, and it is imperative that all four center to center distances are exactly the same. I'm thinking to myself "Why not set them up one at a time in the fixture and silver solder the rods to both ends?" The only adjustable thread required would be on the rod which passes thru the valve nut, to center the valve for timing the engine correctly, and the rotational position of the eccentrics on the crankshaft. Opinions please.---Brian
(http://imageshack.com/a/img924/374/2pADRU.jpg)
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I would just make them fixed. The adjustment for travel is at the slider nut up top, all you need is for them to all be the same exact length from eccentric hole to the bolt hole for the link. With them soldered, also no worry about something loosening up or wobbling.
I like to solder them all up, and THEN drill the top holes just to be safest, using the same jig that made the top links.
As far as offsets go, another way to make them (too late on these, but for future) is to make a slot in one side for a flat bar strap up to the top clevis, and have the tabs of the links offset at either end so the parts can all be the same, no bends needed, and the link bar winds up centered between the two eccentric cams.
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Thank you Chris. I was hoping you would see this and chime in.
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Although I have never soldered any I have made a lot where the strap and rod don't have any adjustment so you should be OK, just watch that your jig does not absorb all the heat and stop your solder from flowing.
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I really do try to make something each day. Some days it's not much. These little guys are destined to become drag links.
(http://imageshack.com/a/img924/9242/k30tLg.jpg)
(http://imageshack.com/a/img922/8688/kNFd1G.jpg)
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Every reversing engine needs a reverse handle, and now mine has one!!
(http://imageshack.com/a/img922/1036/sZdMzP.jpg)
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I am getting to the point where all the major links and levers for the reversing system are finished. I have a few itsy bitsy pieces to make and then I'm ready to try this reverse business out. All of the blue parts in the model are finished.
(http://imageshack.com/a/img924/7340/H5LHIy.jpg)
(http://imageshack.com/a/img923/4299/nRl4cI.jpg)
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I've just had one of those days where it seems I worked awfully hard for minimal results. Most days I go like a whirling dervish and at the end of the day I have a collection of parts to show what I've been doing. Today I made three parts and figured out how to make the final three. I really hope this reversing mechanism works. It is very interesting and there seems to be a lot of small parts involved. I should know in the next two or three days.
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I've just had one of those days where it seems I worked awfully hard for minimal results. Most days I go like a whirling dervish and at the end of the day I have a collection of parts to show what I've been doing. Today I made three parts and figured out how to make the final three. I really hope this reversing mechanism works. It is very interesting and there seems to be a lot of small parts involved. I should know in the next two or three days.
I'm sure you will get it going. The fiddly part is adjusting all four eccentric cam angles, one of those things that gets frustrating then it just goes!
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I'm sure you will get it going. The fiddly part is adjusting all four eccentric cam angles, one of those things that gets frustrating then it just goes!
:thinking: I hope it is not so the 5A and Swan are not adjustable :noidea:
Jo
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I'm sure you will get it going. The fiddly part is adjusting all four eccentric cam angles, one of those things that gets frustrating then it just goes!
:thinking: I hope it is not so the 5A and Swan are not adjustable :noidea:
Jo
Are they turned into the crankshaft rather than separate parts held with grubscrews? The screwd on ones can be fiddly to adjust.
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Are they turned into the crankshaft rather than separate parts held with grubscrews? The screwd on ones can be fiddly to adjust.
They are keyed on.
Jo
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This quest for a reversing engine is taking me in some strange directions. I finally have all of the pieces made, tomorrow I will silver solder up the eccentric strap sub assemblies. In the picture you will see a couple of 1/8" shafts with hex nuts soldered to the ends of them. They are destined to be sawn in half and then threaded on the cut ends to yield four hex bolts.
(http://imageshack.com/a/img924/2593/umUNXD.jpg)
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I have the first eccentric sub assembly fixtured and ready for silver soldering in the morning. I drilled the center out of the 5/8" fixture rod, leaving only a 1/32" wall so that it doesn't act as a big heat sink. There is a very slight air gap between the eccentric strap and the aluminum fixture plate, probably only about .005", but that will stop a lot of heat from being sucked out of the brass strap end as I solder it. The 1/8" pin which locates the small brass end can be pressed out from the far side if I need to in order to remove the sub assembly from the fixture. I have to do two sub assemblies like this and two with a .25" offset bent into the 1/8" rod. I'll let you know how I made out in the morning.
(http://imageshack.com/a/img922/2720/UfiBas.jpg)
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I'm very pleased with how the silver soldering went on my four eccentric strap sub assemblies. I got good flow all around the 1/8" rod at both ends, and good fusion between the steel rods and the brass ends. My "soldering fixture" worked like a charm. I have set one of the assemblies with an offset end up in the fixture for one shot, so you can see the spacer underneath the large end of the strap. I had no problem removing them from the fixture. A two hour soak in Citric acid and then some brisk scrubbing with my small brass bristled brush yields some very nice looking parts---and they are all exactly the same center to center distance.
(http://imageshack.com/a/img923/2938/ODovD1.jpg)
(http://imageshack.com/a/img924/2323/jPn8jY.jpg)
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Up until this point, I have been reasonably sure of what I was doing---as in "Okay, I've done all of this stuff before, so I'm not covering new ground here." Now I have arrived at something totally new, the timing of the two cams at each side of the engine, in relationship to each other. The solid model I have shows a separation of 120 degrees between the high point of the lobes on the two adjacent cams. The part which I have been referring to as the "reversing plate" has a total included angle of about 30 degrees. I have absolutely no idea as to whether this is correct or not. Whoever has created the 3D model I have worked from has done a sensational job, and I can proceed based on blind trust that he has modelled this relationship correctly, but I would really like to have a better understanding of how or why this works.
(http://imageshack.com/a/img922/9256/AW6Yxp.jpg)
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Hi Brian,
You are already familiar with timing the engine in one direction, since you got it running with one eccentric already. For the reverse link, it is just the same process again with the cams offset the opposite way from the crank positions. Easiest procedure is to put the Stephenson link all the way to one direction, and adjust the cams and center the D valve as if there was no reversing. Once that is set, and the engine is running, its just a matter of putting the link all the way the to the other end (with the other two eccentric links directly under the valve rod, sometimes there is the possibility that the link allows going beyond that point), and set the two eccentrics now in play to the midway point on the other side of the cranks, and getting it to run in that position. As long as the straps are all the same length, the D valve is symmetric, and the link is symmetric, there is no need to touch the D valve position. Calculating the included angle is handy to get the starting point, but there may be some tweaking to that angle in the end. With the cams set with the reversing link at full throw both ways, then the in-between settings will take care of themselves.
The length of the link bar can vary a lot from engine to engine - was looking at some photos of the hoist engine for the steam shovel, and it looks like due to a lack of space between the floor plate and one of the gear shafts above it, they used a very short link, only about 10 or 12 degrees, where many marine engines (and yours) used two or three times that, which gave better control of the steam usage.
Chris
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Thank you so much Chris. I've known all along that I would have this question when I reached this stage of development on the engine.--Brian
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Thank you gentlemen-My knowledge of steam engine valve setting so far, extends to the eccentric position relative to the crankshaft and the slide valve relative to it's position in the steamchest. The "throw" of the eccentric should be equal to 1/4 of the "throw" on the crankshaft. My crankshaft has a "throw" of 3/8" (which gives a total stroke of 3/4"). The "throw" on my eccentric is .094" which gives the slide valve a total travel of .188" . When the piston is at bottom dead center, the eccentric lobe should be half way thru it's highest and lowest points of travel (that is how you position the eccentric rotationally in respect to the crankshaft. Also, at this time and position, the slide valve should be exactly half way thru it's full travel (3/16") in the steamchest. This method has always worked well for me. The set up for reversing apparently follows exactly the same procedure when setting up with the straight rod directly below the valve rod vertically. When the reversing handle is rotated thru 30 degrees, this brings the offset rod into position directly below the valve rod and hopefully makes the engine run in reverse. I think I've got it, but will only know when I have everything reassembled. I'm a bit unclear what happens at the other cylinder, as the crankshaft is 90 degrees "out of phase" yet is still connected to the same reversing lever.
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Basically set it up as two separate engines, with the reverse quadrant in one position set it up to run in one direction by adjusting the rods that line up with the valve rod as you would a non reversing engine. Set one cylinder and then set the second as you have done to run it as a non reversing engine.
Then move the quadrant to the othe position and set up the other two eccentrics for an engine running in the opposite direction, you should not need to make adjustments to the valve just the position of the eccentrics
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Here is a short video of me practicing my Canadian Newfie accent and demonstrating the working of my first stage of reversing mechanism.
https://www.youtube.com/watch?v=d2UiP4gDUKE
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The parts are coming together nicely, sounds like you've been practicing the accent too! :Lol:
:popcorn:
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A gentleman on a different forum has shown me the error of my ways. It isindeed correct that the stroke of the steam valve is what determines the "throw" on the eccentric, and is not directly related to the "throw" of the crankshaft. I'm sure that there is some esoteric science that explains why steamchests would be longer or shorter, requiring a greater or lesser "stroke" of the steam valve, but it is a road I don't really want to go down right now. As far as "lap" and "lead" are concerned, I have a glimmer of why this would be so, as it relates to internal combustion engines where the valves don't open and close when the piston is exactly at top or bottom dead center. I have always set my model "steam" engines up with the steam valve positioned exactly in the center of it's travel when the piston is either at top or bottom dead center, and that has always worked for me. I will let you know how that works out with this engine.---Brian
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The only critical part is that the valve opens the passage to steam after TDC, and closes it before BDC, how you get there doesn't matter.
And the other fellow is right, the throw on the valve is determined by the spacing of the ports, not the length of the crank. I have a beam engine with very long cylinder, but ports and steam chest are sized like a shorter cylinder.
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A short video of the complete Stephensons reversing linkage on my engine.
https://www.youtube.com/watch?v=84W3HiL-je4
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This thing is kicking my butt!! After adding all the little bits and pieces, now I can't get it to run at all. :cussing: :cussing: I've decided to go back to basics and completely isolate one cylinder and to get it running on one cylinder first, then isolate the running cylinder and set up the other one. This works great if I can get it running on one cylinder, which so far is eluding me. I must be getting close, because in one position that the valve was set, it oscillated. Flywheel didn't go all the way around---It sat there and went back and forth. That's something I haven't seen before. It seems that the secret is getting the steam valve into the right position, which for me has always been at the center of it's travel when the piston is at bottom dead center. Of course the problem is that with the steamchest cover plate in place, you can't see where the valve is, so you have to resort to measuring the amount of steam valve rod extending beyond the gland nut, in it's maximum and minimum positions, then decide on the "happy medium" and set the engine up to run that way.---And of course this may not be accurate either, because without being able to actually see the steam valve, I don't really know if it's centered or offset to one end or the other of where it should be in the steamchest.
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Stuarts pdf on how to set up an engine with reversing gear may help
https://web.archive.org/web/20060713173202/http://www.stuartmodels.com/pdfs/SM-Timing.pdf
Also remember that when you turn the engine end for end to set up the second cylinder the crank will be rotating the opposite way as you look at that end
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Isolating the cylinders, just feeding air to one at a time, is a great way to go. I like to put in low pressure air, enough to feel the push, and hand turn the flywheel while feeling when the valves open and close. That way I can fine tune the center spot as well as the eccentric angle to the crank. Tiny angle change can make all the difference. A felt tip line on the eccentric and shaft make it easier to tell how much you are moving it.
You valve slider dimensions must be okay since it did run once. Methodical changes one at a time will get you there.
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Brian
It’s very easy to do
Put it in full gear one way look in valve chest rotate the engine the valve should uncover the port the same at both ends do not worry about the position of the piston at this stage , now put the gear in the other end and repeat if it’s not still uncovering the port evenly at both ends then the valve gear is not correct in the dims. To adjust move the valve on the valve rod
If the above is ok then time the valve put the piston at TDC and rotate the working eccentric in the direction you want until the respective port is just uncovered , repeat for with the gear in the direction and repeat with the working eccentric ,remember it now going the other way
Repeat for the other end or test that one , but when you do the other end think about the rotation make sure it matches
I have built a good few loco’s with Stevenson’s loco link and many more with walschaerts gear
All you need is equal valve movement and the eccentric set so that is just opens the port at TDC
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Thanks guys--I'm trying.---Brian
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No need to see the valve for setting the eccentrics, Brian!
turn the engine crankshaft by hand in the forward direction, when the piston crosses TDC, look at the valves, the forward valve starts to open the upper steam port, and moves in the same direction as the piston (for this short part of the cycle only), even if you don't see the valve, you can see its direction of rotation : downwards, the valve being in advance on the piston.
When the piston passes midstroke, this valve moves now upwards, in the opposite of the piston; this is the valve which corresponds to this rotation.
The same holds true for the second cylinder, for the same direction of rotation of the crankshaft, but looking at the engine from the other side can be confusing as Jason said.
once the eccentrics are roughly set, the engine runs, and the setting are adjusted up to the best...
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AWRIGHT!!! We've-got foreword and reverse on one cylinder. Hooray Hooray---Happy Dance. :pinkelephant: :pinkelephant: :pinkelephant: Stuart--It was your post that done the trick. Thank you so much.---Brian
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Whahoo!!!
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Brian,
Great that you got it. :whoohoo:
Art
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Brian
It’s a pleasure that’s what forums are for to help others and to spread our knowledge to others
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Progress report. I have everything back together but the cylinder closest to the flywheel is still acting quite wimpy. I need a break from this before I break out in hives!!! I have to go across town now and do some business, and maybe when I get home later I can try a teensy bit of adjusting on the eccentric on that underperforming side. If I'm really, really lucky, that may be all it takes. Hope--hope.
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Progress report. I have everything back together but the cylinder closest to the flywheel is still acting quite wimpy. I need a break from this before I break out in hives!!! I have to go across town now and do some business, and maybe when I get home later I can try a teensy bit of adjusting on the eccentric on that underperforming side. If I'm really, really lucky, that may be all it takes. Hope--hope.
If it is not pushing hard in the up OR down stroke, then it may be that the valve slider is a tad too long, and not opening the port all the way. Or there is a bit of cylinder gasket sticking out too far and blocking the port into the cylinder (done that one a few times!)
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Today we had success. The engine ran on both cylinders, forward and then reverse. It's not video worthy yet, but it certainly made my old heart go pitter patter. I had a tough time getting the eccentrics set in the correct position on the second cylinder. I could get it to run, but only clockwise. then I would adjust it a little bit and it would only run counterclockwise. Finally, I played "Around the clock" and moved it in 20 degree increments until I found the sweet spot, where it would run in either direction as dictated by the reversing levers position and in concert with the first cylinder. At the end of the day I scrounged around in my shop until I found a piece of steel to make a second flywheel. I'm not sure if I actually need it or not, but even if I only use it during "set-up" procedures you can never have too many extra flywheels around.
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Okay kiddies--Here we go!! A running and reversing, all bar stock engine. Thank you so much to all of the forum members who stepped up and offered assistance when I was trying to figure out how to make the reversing mechanism work. Someone please give me a heads up if you can see the video alright.---Brian
https://www.youtube.com/watch?v=t-oKiCXyFyE
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That looks and sounds terrific!!
:whoohoo:
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In order to cover some of my expense in building this engine, I will exchange a complete set of my plans for a $25 Canadian donation.
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Looks and runs good Brian :)
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Well done Brian!! A lovely little engine and it seems to be running as good as it looks :ThumbsUp: :ThumbsUp:
Bill
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I see that my first post on this engine was on the 4th of September. That's two and one half months of my life that demanded work on the engine just about every day. I'm sure that many were bored to tears with my posts from almost every day, but they mostly all showed the constant development of the engine. It was fun, taught me a few things, and was a nice break from i.c. engines. I still want to develop a nice intake and exhaust set-up for this engine, but I'm relieved that it is 99% finished and that it ran. This is the first time I have downloaded a 3D model from someone I don't know and have never met, and created drawings and working components from it. Whoever created that 3D model did an excellent job. I found one very minor error, and that was all. When you consider the vast quantity of math data that goes into developing accurate 3D models, this guy was first class. Thank you to all who commented or helped out along the way. The fat lady hasn't sang yet, there will be a few more posts showing the intake and exhaust manifolds, but we are almost thru here. It's been a great build.
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Congratulations Brian,
It is a treat to see this engine running forward and reverse and the nice-looking linkages all complete in brass.
Your posts are never boring! As you are learning I am learning and as I have said before I like your "warts and all" approach to your posts. There are many things embedded in what you put up that ultimately make it into my repertoire of shop knowledge.
I will continue to be watching the final steps as you finish this one.
--ShopShoe
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Looks great, now to get it "back to Steam" you need a boiler and burner.
Gerald.
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Looks great, now to get it "back to Steam" you need a boiler and burner.
Gerald.
Nah, I've made it thru 71 years without blowing myself up, burning myself badly, or scalding myself. I'll leave steam up to the Casey Jones's of this world.
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Same age Brian :ThumbsUp: :old:
Steam is OK like all things treat it with respect it deserves it or it will bite
let me see whats the worst thing that has happened to me , did open wheel car racing that was OK , escaped from a 10 foot lenght of 15 foot die pipe that fell and hit a beam above my head that was OK then dang it I got mumps at the ripe old age of 22 , yes I got the dreaded male complications big swellings ouch that was not good :stir:
all above are true but I am still messing with steam the only problem with steam is driving model loco's your nether regions are not to far away from the back head if the gauge glass breaks :censored:
great news on the engine
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I have a bunch of hexagon brass rods 7/16" across the flats which my friend gave me last year for fixing his motorcycle sprocket. I think they will make pretty cool looking intake and exhaust manifolds.
(http://imageshack.com/a/img923/1023/6GLNT5.jpg)
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Hi
Very nice Brian. :ThumbsUp:
I have followed your build quietly in the back ground from start to finish and enjoyed it immensely.
Cheers
Rich
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Thank you gentlemen. I post away blindly here, hoping that people are following. It is nice to hear from you all, and know that some people actually were.---Brian
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Hi Brian, I am another who always turns first to your posts. Rest assured they are most interesting and never boring, even when you build one of those infernal combustion machines you seem to favour. You have even inspired me to consider building one if I can ever get my skills up a bit.
Your setups and clear pictures always inspire. And the Newfy accent reminds me of the Scout Master I used to assist, not far from you, in Corunna, Ontario. And the great times we had, working and living there.
Thank you for your efforts in posting great pictures of your work,
MJM460
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Brian..........I just checked and, as of now, your build thread has had 13,193 visits. I'm responsible for more than a few of those myself! :praise2: Your builds are always particularly interesting in that you can take an idea and turn it into a working engine...............complete with drawings! :ThumbsUp:
Jim (another 71 year old)
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Just a little bit of Loctiting/soldering/hole plugging/polishing, and the beast will have manifolds.
(http://imageshack.com/a/img923/6912/vSfEuU.jpg)
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How are going to attach the manifold to the engine? That's one thing I have never come up with a good way to do, always wind up with screws I can't get at.
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How are going to attach the manifold to the engine? That's one thing I have never come up with a good way to do, always wind up with screws I can't get at.
Loctite---or maybe J.B. weld. Okay--I've had my dinner and can give you a little better answer. Most of the stuff I build is single cylinder where you don't need a manifold. I generally tap the intake and the exhaust ports for a standard 1/4"-20 or a 5/16"-18 thread. I only have a few twin cylinder engines, and I think your method of making a bolt on flange is the best way to attach a manifold. Most of the time when I make up manifolds for twin cylinder engines, I make it up as I go along. By the time I'm down to the last stages of an engine build, I generally opt for something "quick and nasty" that still looks and functions okay. I do sometimes use Loctite if the situation will allow, knowing full well that if I ever have to take that manifold off the engine, a little bit of heat will be called for. I don't really have a problem with that. Most of my engines are "shelf queens". I build them, I make a video of them running, I play with them for a week, and then it's up on a shelf. Sometimes if I have a visitor and they are interested I will get one of the engines down and run it for them, but that doesn't really happen very often.---Brian
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I've silver soldered as much as I dare. This goes into my citric acid pickle solution now and sets overnight. Tomorrow I will "dress" the ends of the hexagon parts , clean up any remaining crud with a brass bristle brush, then Loctite things into place on the engine.
(http://imageshack.com/a/img924/6569/LKdm0U.jpg)
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And this, gentlemen, is THE END! The manifolds turned out very nice, the engine runs in forward and reverse, the project is completely finished. Thank you to all who have tagged along for this build.---Brian
(http://imageshack.com/a/img924/1241/IgPsvX.jpg)
(http://imageshack.com/a/img924/8128/60w0Jv.jpg)
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The manifold attractions of your model are made even more attractive by the excellent manifold.
Thankfully, my puns are exhausted...
Very nice!
John
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Simplyloco--That's where a lot of the fun is.---Making it up as I go along.
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Yeah, I know. I said I was done with this but "Idle hands are the devil's workshop" my grandma used to say---
https://www.youtube.com/watch?v=bGLXclJdPI0