Model Engine Maker
Engines => From Plans => Topic started by: Bear on September 12, 2020, 02:25:44 AM
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Starting on my 2nd engine, Elmer's Horizontal Mill engine #43. My first was an oscillating engine.
However, I am off to a unique start :-[. I drilled and countersunk 2 of the base holes for the cylinder. Still need to do the holes for the column. The point where I did not go in accordance with the plans was countersinking the wrong side of the base plate so that my engine will sit kind of backwards to the plans. See photo below.
I don't think this will cause any issues in the build (other than maybe confusing me when I look at the plans). The orientation will be similar to that of Elmer's # 33 Mill Engine. Anyone see any issues in proceeding in this manner?
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Been there, done that!
Reversing everything will work, but as you said will be confusing when reading the plans. Other options, will the bad countersinks be covered by other parts? If so, leave them. Or, drill them out larger and plug them, loctite in rod and redrill. Or use our old friend JB Weld to fill the countersinks and drill through the epoxy. Not that I have done any of those things. Um, today anyway!
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Good ideas. I did measure to see if I could just countersink from the other side; but, the depth of the holes relative to the thickness of the material is awfully close. Maybe, the disorientation would be a good learning experience ;D.
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I think that just for the sake of simplicity, I'd do what's necessary to get things set up as the plans call for........even if you remake the part. It's just a small piece of aluminum plate. Might save other problems later.
Jim
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Well, Jim and crueby, after thinking a bit more on your helpful posts, I went and did some measuring, and determined it will be an easy fix. The portion with the holes can be cut out to form the somewhat "L" shaped based, which I will do after I turn over the base and re-drill my holes, and then countersink from the other side. No one will ever know ;D .
Thank's for the help, guys.
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I'm glad it's working out OK. I sometimes mark things, even with arrows pointing a standard direction (my own standard) to keep track of it all.
If (when?) you have to remake something, the good thing will be it will take less time to make the new version.
ShopShoe
PS: Another thing I sometimes do is to go ahead and blue the stock on the face I need to work in the next work session before taking a break. That way I will come back to lay out the feature in the right place.
SS
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Look here, maybe it helps.
arona
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Another thing that may confuse you Bear is you are using a centre drill to form the countersink: Centre drills have an angle of 60 degrees, countersinks are 90 degrees. It would be better if they were 90 degrees to fit the head of the screws ::)
Jo
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You are absolutely correct, Jo. This time I will drill through (going to do that now), and then I will buy a proper countersink, and finish the holes. Thank you for all the responses so far.
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Metric countersinks have a 90 degree included angle (45 degree half angle).
Inferial countersinks as used in the USA have an 82 degree included angle (41 degree half angle).
https://www.kbctools.com/products/search/countersink
It's worthwhile checking your screws to see which is needed. I made a gauge to simplify this...
https://www.homemadetools.net/forum/countersink-gage-56314#post83429
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Or you could just counter bore them and use cap head screws :)
If you are buying CSK bits I'd also suggest adding a spotting drillor two to the shopping list as they are a bit more robust than ctr drills which are best kept for when you specifically need a 60deg hole eg when drilling for tailstock ctr support. Here in the UK a 90deg spotting drill can also double as a CSK so you don't have to go back and CSK the holes unless in a case like yours they are on the opposite side
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Marv and Jason, thank's. I will try to figure out the angle of the 6/32 screws, or I may do the cap screws. Will see. The local supply house is closed until Monday. In the meantime, I have finished drilling all 4 holes.
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Progress. Ran the fly cutter over the top surface. As you can see in the photo, there are 2 extra holes that I will have the option of removing by making the L shape. In any event, I will leave the rectangle shape until I have countersunk or counterbored the holes which might help for clamping purposes.
Also, a photo of some brass I just received yesterday from OnLineMetals.com. This will get me through this project, and them some.
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Or you could just counter bore them and use cap head screws :)
That's what I did on mine. worked great.
Jim
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Got a little more done today. I worked on the column. I still have it in the mill vise as can be seen in the photo. Question: Do I need to ream the 3/8" crankshaft bearing hole, or will simply drilling be okay since a bearing is going in? I really don't want to spend the money on a 3/8" reamer. I will buy a 3/16" reamer for the bearing hole, or possibly oversize the hole to use the 1/4" reamer I do have.
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Drilling alone will tend to give a slightly non-round hole, but as you say if a bearing will be there, that should be okay. If you have a boring head, drilling a size down and finishing with the boring head is another option in cases like that. For making bearings, I usually turn the on the lathe, drilling small and boring out with a small boring bar to size, that guarantees that the hole is concentric with the outside of the bearing, and is round.
:popcorn:
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Thanks, crueby. I like the boring head idea; however, I don't have one, but have been meaning to get one ;D; looking at the Taig or Sherline. I will definitely be doing the bearing on the lathe.
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How about I use a 3/8" end mill instead of a drill? I would think, correct me if wrong, that the end mill would be more accurate than a drill. Maybe I would want to start with a 1/4" drill then end mill??
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Big risk of chatter that way, enlarging the hole. Can work with a very rigid machine, risky with smaller machines. Better to drill smaller and go up one drill size at a time, especially if you have numbered and fractional drills.
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Thank's. I think I will just proceed with the incremental drill sizes like you say.
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Its the kind of thing that is worth experimenting with if you have any scrap bits of the plate. Great way to learn alternative methods and figure out speeds and feed rates. There are almost always multiple ways to do any shaping.
When plunge cutting with end mills, check to see if it is a center cutting cutter, some don't have cutting edges right to the middle of the end, so would need a pilot hole.
:cheers:
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Good points, crueby. I did look at Jim's build thread for the same engine, and he used a reamer for this 3/8" hole. I will check prices on the 3/8" reamers. Thank's again.
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If you can drill it 1/64 down then a 3/8" milling cutter will take no more off than a reamer so should be minimal risk of chatter, just run slowly. really depends if you have a 1/64th increment drill set.
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Good points, crueby. I did look at Jim's build thread for the same engine, and he used a reamer for this 3/8" hole. I will check prices on the 3/8" reamers. Thank's again.
My thought on tool purchases is that if I need something once...........I'm going to need it again in the future. :)
Jim
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Thank's, Jason and Jim. I will check my drill inventory, and I did check the price on a reamer; not as bad as I thought it would be.
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Good news :). I ordered the 3/8" reamer from Little Machine Shop at a very good price. By the way, the customer service there is excellent. If history repeats itself, I should have it in 2 days.
In the meantime, I may do some lathe work for the enngine so as to not mess with my mill set-up.
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Should be receiving my 3/8" reamer any minute now. Problem is that I don't have the right size drill if I want 2% left. Calls for a 9.25mm drill that I ordered but is not scheduled to arrive until next week. The strange part that is related to the question I am about to pose is that if I do a 3% hole, the measurement is .36375". Online charts I have looked at show this dimension; but also show a drill size of 23/64" (which I do have). The 23/64" decimal size is only .3594", which is about 4%.
Can anyone tell me whether 4% is okay for aluminum? I thought I read that holes should be pre-drilled for reamers for 2% to 3% material left.
What would you do? Wait for the 9.25mm drill or proceed with the 23/64" drill :-\?
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I have never really seen any metric drill bits with 0.05 mm. 'resolution' :thinking:
The common as muck ones are in 0.5 mm. steps and the finer steps are 0.1 mm. wich I would think would be close enough for Rock'n'Roll :Lol:
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I've frequently used drills that are 1/64th larger than the reamer as a starting hole. It may not be ideal, but it has worked for me. I'd say you'll have no trouble with that in either aluminum or brass.
Others please feel free to correct me if you disagree.
Kim
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Should be receiving my 3/8" reamer any minute now. Problem is that I don't have the right size drill if I want 2% left. Calls for a 9.25mm drill that I ordered but is not scheduled to arrive until next week. ...
What would you do? Wait for the 9.25mm drill or proceed with the 23/64" drill :-\?
Use the 23/64th drill.
I was unaware of the 2% rule :headscratch: I just use a drill that is undersized by a bit. So for a 4.76mm reamer (3/16" ::) ) I would use a 4.5mm drill and for a 3.18 (1/8th ) I would use a 3mm . So they equate to even bigger percentage wise than your 23/64th drill. Most of the larger imperial stuff I just use the next 64th size smaller than the reamer.
And run the reamer slower than the drill - a lot slower.
Jo
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I have never really seen any metric drill bits with 0.05 mm. 'resolution' :thinking:
We used to use them all the time for Defence purposes. They were particularly nice as they were ground to the correct angle for the material they were using on the production line. I hate to think what they cost ::)
:thinking: I should have tried scrounging the old ones as I seem to recall they were limited on how many holes they were allowed to drill before it was deemed the drill may not be accurate any longer.
Jo
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I have never really seen any metric drill bits with 0.05 mm. 'resolution' :thinking:
The common as muck ones are in 0.5 mm. steps and the finer steps are 0.1 mm. wich I would think would be close enough for Rock'n'Roll :Lol:
Guhring appear to do drills by 0.01mm:
https://www.guhring.com/BrowseProducts/Products/High-Speed-Steel-Jobber-Length-HSS-HSCO-PM-Drills
From Cromwell / Zorro ??
Have to agree with your second sentence though .... ;D
Dave
Link is a bit flaky ... Click 'Diameter mm' on the filter panel R.H. side to see all diameters.
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I've frequently used drills that are 1/64th larger than the reamer as a starting hole. It may not be ideal, but it has worked for me. I'd say you'll have no trouble with that in either aluminum or brass.
Others please feel free to correct me if you disagree.
Kim
1/64th smaller, I hope, not larger?
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Thank's for all the responses. I think I will try the 23/64 drill today.
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Here is the progress so far. Did use the 23/64" drill, and then reamed with 3/8" reamer. I then drill the next hole which called for 3/16"; however, i have a #11 reamer and not a 3/16", so I made it slightly oversize (.191" vs .1875"). I next moved to the final hole for the reverse lever, and have stopped before center drilling. See photo.
The reason I have stopped is that the hole will be very close to the top of the stand. I don't know where I may have gone wrong. I measured and re-measured everything multiple times, and the hole seem to be in the right location. I can't figure out what I might be doing wrong. I'll have to think on it.
I wonder if moving the hole down slightly will affect anything other than the spacing on the lever itself. Comments would be welcome.
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I've frequently used drills that are 1/64th larger than the reamer as a starting hole. It may not be ideal, but it has worked for me. I'd say you'll have no trouble with that in either aluminum or brass.
Others please feel free to correct me if you disagree.
Kim
1/64th smaller, I hope, not larger?
Oops, yeah, I meant smaller, of course! Sorry if my slip steered anyone wrong there! :embarassed:
Thanks for the catch, Chris!
Kim
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Does look like the overall length of the part should have been 2 3/8" not 2 5/16"
Yes you could move it down 1/16" and then make the radius of the slot in the lever 9/16" rather than 5/8"
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Thank's, Jason. I will go head and move the hole down 1/16".
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I completed the aluminum column today. In the picture, it is just resting on the base because I have not yet counter bored the holes in the base for the screws. Waiting for the screws to arrive. Also some pictures of cutting the angles of the column on the mill.
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Coming along nicely! :popcorn: :popcorn: :popcorn:
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Thank you.
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Wanting to make the main bearing now. The plans call for bronze. I don't have bronze (too expensive); but I have brass. I see that Jim (in his build thread for his #43 engine) used brass instead, not anticipating much use.
Jim, how's the brass holding up? Any other comments on using brass or other metal, instead of bronze with a steel crankshaft are welcome.
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While bronze might be better for wear, I'm sure brass will do just fine for your model and the amount of action it's likely to see.
I initially used brass anytime bronze was called for. But as I got more serious I have started to pick up some bronze here and there. But you should be fine with brass as the bearings here.
Kim
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I agree, brass will do just fine.
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Thank's, Kim and crueby. I will proceed with the brass. In the meantime, I have rough cut (saw) the aluminum cylinder; and, I have rough cut (grinder) a piece of rectangular steel for the Tilting Guide. I am going to try using the rectangular piece, instead of a round piece, for less waste, and for what I think may be an easier milling set-up. I will just set it up in my 4 jaw, and then transfer the chuck directly to the mill on this Taig attachment https://taigtools.com/product/3-4-16-chuck-adapter/ .
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Wanting to make the main bearing now. The plans call for bronze. I don't have bronze (too expensive); but I have brass. I see that Jim (in his build thread for his #43 engine) used brass instead, not anticipating much use.
Jim, how's the brass holding up? Any other comments on using brass or other metal, instead of bronze with a steel crankshaft are welcome.
No more than these engines get run, the brass will hold up just fine. If the brass bearing should happen to wear out, it's simple enough to make a new one.
Jim
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Thank's, Jim.
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I didn't quite know where to put this information on very good clearance deals at Grainger. I thought that members could benefit. I have no affiliation whatsoever with Grainger other than as a new customer. I stumbled upon them when looking for machine screw size dies. I ended up buying a 3-48 die for $2.37, 2-56 die for $1.48, some reamers for well under $2.00 each, boxes of screws in various sizes starting at 2-56, and even a small bore gauge set for about $5.00.
In any event, if you are interested in this type of item or other items, you may desire to check out the Grainger website and search for "clearance" items.
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A little progress today. I gave some more thought to what I had planned to do with the Tilting Guide in my post (#44) above. Instead of finishing in the mill, I finished the mill work today. so that all there is left to do is cut the length to size, and then turn the round portion in the lathe.
I figure it would be difficult to turn the round portion up against the chuck, which is what I would have had to do if I proceeded as originally planned. Then the mill work would have little support from the small chucked diameter.
I hope I am going about this correctly. I hope I will be able to chuck the rectangular portion in the independent 4 jaw chuck so that the round portion of the tilting guide will be square to the rectangular head.
Here are some pictures, including what I have made so far. The ugly square of aluminum is a rough cut for the cylinder that I will attempt to true up in the mill.
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Today, I finished the Titling Guide. There was so little for the 4 jaw chuck to grip, so I made a tight fitting aluminum block that fit into the slot of the Tilting Guide. I machined it so that the ends were at an exact measurement with the ends of the Tilting Block. You also see that the chuck jaws gripped the block and the Tilting Guide so that the block could not come loose. See photos. Although the photos make it look like the block was not square in the guide slot, it was square.
Then after cutting the Tilting Block to length, I proceeded with squaring it in the 4 jaw chuck. I think I got it squared ok, because it turned out nicely. I also took very light cuts so as to avoid a potential for the piece to be knocked out of alignment, or even worse, come out of the chuck.
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Nicely done! One thing to consider for next time - for a part like that, putting a small dimple in the end and supporting it with a live center in the tailstock can reduce the pucker factor a bit.
:popcorn: :popcorn: :popcorn:
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Good job but wouldn't it have been easier to reverse the order of operations; first turn cylinder, then cut slot. A fabrication would also have been a possibility; mill channel, drill hole in bottom and silver solder in length of rod. On the one I built years ago, I went with the fabrication.
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Nicely done! One thing to consider for next time - for a part like that, putting a small dimple in the end and supporting it with a live center in the tailstock can reduce the pucker factor a bit.
:popcorn: :popcorn: :popcorn:
Thank's. I was going to use my tailstock center; but, I didn't have enough length with my center, unless I did something wrong.
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Marv, I think you are correct that it would have been easier the way you stated; however, I am prone to doing things the hard way ;D.
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Nicely done! One thing to consider for next time - for a part like that, putting a small dimple in the end and supporting it with a live center in the tailstock can reduce the pucker factor a bit.
:popcorn: :popcorn: :popcorn:
Thank's. I was going to use my tailstock center; but, I didn't have enough length with my center, unless I did something wrong.
I had same issue with the stock Sherline center not reaching far enough, found an aftermarket longer one, more recently Sherline came out with a long one they market for pool cue turning.
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Crueby, that is good to know. I have been meaning to do something about mine.
I just got done rough squaring my cylinder, rough being the operative word, because it is not exactly square. Will have to start again with my square sides, and hopefully I can square it all up to size. I am through for the day. Time for a beer :cheers:.
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Okay, got the cylinder moving along by drilling and tapping the mounting holes, and boring the bore. I have also mounted the column using a counter bore for the screws. Also, I shaped the base. As you may recall in one of my earlier posts, I drilled the base upside down for the cylinder, so I reversed it and did it correctly. I was not decided on what to do with the 2 extra holes. I ended up milling one out and leaving another as a potential mounting hole, as can be seen in the photos.
Now to try to figure out how best to drill the 25 degree angle port holes in the top of the cylinder.
Edit: I did use the 4 jaw chuck to bore the cylinder. I should have taken a photo.
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Looking good! For the angled holes, one thing that can help is to use a small end mill to create a small flat at the angle of the hole, so that you can center drill and drill the hole into a flat surface that is perpendicular to the hole. Otherwise, the drill will want to skate downhill slightly.
:popcorn:
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Thanks; good idea.
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Got the vise and mill all "trammed" to get ready for the port holes at the 25 degree angle. Think about using an adjustable triangle that I have and set it to 25 degrees. Then I will attempt to set the angle of the cylinder up against the triangle in the vise, and then drill from the bore out. Please let me know if there is a better way without angle blocks or special attachments.
While I was not ready to start the port holes, I did start on the piston rod. Threaded one end after getting it to size. it is now sitting in the 4 jaw chuck with the part opposite where the piston will be extending slightly from the jaws so that I can machine it accordingly.
However, I am at a standstill on how to mill the slot in the piston rod. The plans appear to call for a .093 wide slot. The smallest diameter end mill I have is 1/8" (.125"). Would it be okay to make the slot .125" or should I just order a 3/32" end mill? The width of the area containing the slot is .250, thereby leaving only .0625 thickness around the slot. Suggestions would be appreciated.
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Decided to work on the cylinder port holes in the manner described in my last post. I used an adjustable angle set at 25 degrees.
Then I tried a wiggler to find the edge. Did not work. I then went with a center drill to find the edge and it worked. Started the hole with the center drill and then drilled out. Unfortunately, one of the holes was off center by about .017" when it came out the top of the cylinder. Must have been something I did wrong when drilling. They are centered in the bore. They came out at the right places on the top of the cylinder as to distance from the edge.
I then proceeded to mill the slots; but, I messed up in measuring the first start point. The second one was done correctly, I think. I then made the center hole. Does not look too good in light of the discrepancy between the slots and the holes; however, I am hoping the functionality will not be effected. What do you think about whether the functionality will be effected.
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Got the vise and mill all "trammed" to get ready for the port holes at the 25 degree angle. Think about using an adjustable triangle that I have and set it to 25 degrees. Then I will attempt to set the angle of the cylinder up against the triangle in the vise, and then drill from the bore out. Please let me know if there is a better way without angle blocks or special attachments....
I try to avoid having a part tilted in the MM vise jaws with no support below; too much chance of the drilling pressure rotating the part - DAMHIKT.
If you lack angle blocks of the required size, make one in scrap, even wood will generally work. Arrange a stop so the drilling pressure doesn't squeeze the angle block out of the vise. These impromptu angle blocks usually need not be high accuracy; I've often used wood that's been bandsawed to the required angle. Mark with the angle and save them; your collection will grow.
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Thanks Marv. Maybe the lack of blocks is what caused one of the holes to go off-center.
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However, I am at a standstill on how to mill the slot in the piston rod. The plans appear to call for a .093 wide slot. The smallest diameter end mill I have is 1/8" (.125"). Would it be okay to make the slot .125" or should I just order a 3/32" end mill? The width of the area containing the slot is .250, thereby leaving only .0625 thickness around the slot. Suggestions would be appreciated.
It's not cast in concrete that you need to mill that slot with an endmill.
Do you have a slitting saw 0.093" or less in thickness? If so, cut the slot with that.
(Having a few thin slitting saws in the tool inventory is a good idea if one intends to make lots of miniature parts.)
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I don't know the details of that engine, if its a slot in the end of a rod, another option is to rough cut with a hacksaw and finish it with small files.
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It's not cast in concrete that you need to mill that slot with an endmill.
Do you have a slitting saw 0.093" or less in thickness? If so, cut the slot with that.
(Having a few thin slitting saws in the tool inventory is a good idea if one intends to make lots of miniature parts.)
Thanks. Great idea. I do have a slitting saw that is .028 thick. On the other hand, I do need a 1/16" end mill for a couple of slots in the valve plate where a slitting saw would not work. So, I was going to order a 3/32 and 1/16 end mill. The price of the end mills is as much as the shipping. I gotta get my money's worth on the shipping so I guess I just need to buy more stuff ;D.
Thanks, crueby. It is for the piston rod. I am afraid I would butcher it with a hacksaw.
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It should be obvious but drill the cross hole AFTER cutting the slot, not before. This will ensure that it's perpendicular to the slot. If you're worried about the slot closing due to the drill pressure fill it with some wood (popsicle stick or coffee stirrer) before drilling. The thin wood/metal in the slot will help to orient the part in the vise so that the slot is horizontal.
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Thank for the tip, Marv.
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For the smaller end mills, I have gotten some on Amazon this past year that have worked out well - was iffy about ordering off-brand cutters, but these have worked out okay and I've used them for things like valve plates and fine slots. Being so thin they will not take an aggressive cut like a bigger one, but with a slow feed they work well. For a longer slot, I first drilled a row of holes to remove most of the material, then connected them and cleaned up the slot with these cutters. Too small for the normal end mill holder, I've chucked them in the drill chuck which normally doesn't work for the bugger cuttters.
https://smile.amazon.com/gp/product/B07FSRQHN5/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
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Thanks, crueby. I did end up ordering some from KBC for a little under $5.00 each, USA made. I also ordered some other stuff ;D.
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Thanks, crueby. I did end up ordering some from KBC for a little under $5.00 each, USA made. I also ordered some other stuff ;D .
I haven't seen them before, looks like a good selection. Going to be browsing (drooling) over their catalog...
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Thanks, crueby. I did end up ordering some from KBC for a little under $5.00 each, USA made. I also ordered some other stuff ;D .
I haven't seen them before, looks like a good selection. Going to be browsing (drooling) over their catalog...
Don't miss their sale catalog ;D.
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Straying a little. I started working on the flywheel. I had a piece of brass looking material from a salvage yard that I purchased wit the intent of eventually using it as a flywheel. I should have taken pictures of the "before"; but, it was a gear of sorts. I did take a picture of it on the lathe, in progress.
You will note the extra large bore. I am also making a steel bushing for the bore with a tight fit, that is also in process.
I also took a picture of the swarf to see if any of you can determine the metal. I thought it was brass; but, it seems a little heavy, and the color is slightly more reddish. I have little experience working brass; but, the piston rod I made of brass made mini chips when turning. As you can see this stuff made some long continuous chips with some purple.
Can anyone identify the material from the pictures and description give above?
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Possible that the metal is either 260 brass (aka cartridge brass) or maybe a bronze alloy. The purple makes me suspect phosphor bronze, which can machine off with very hot swarf. The 360 brass normally gives the small chips as you say. Lotsa alloys out there, hard to tell sometimes if from scrap.
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Thanks crueby. Kinda thinking there is some bronze in there. I won't have a large enough of the material left to make the bronze bearing which I planned to make out of brass; however, I will have enough material left to make the bronze "sliding block" out of material that may be better than brass when bronze is called out.
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Received my 3/32" end mill today, and I finished up the piston rod. Getting ready to finish the flywheel.
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A new tool is a lot of fun, especially when it works!
:popcorn: :popcorn: :popcorn:
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Looking very nice. Did you cut that slot in one pass, or did you take multiple cuts? If multiples, what depth of cut did you make? Just curious. Looks like very nice parts!
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Looking very nice. Did you cut that slot in one pass, or did you take multiple cuts? If multiples, what depth of cut did you make? Just curious. Looks like very nice parts!
Thanks, Stuart. I made multiple cuts of .010" deep with a couple about .015 deep. I probably could have gone deeper; however, the part was mounted in a four jaw chuck, only being held on the shaft diameter of .138". Also had to have the side milled portions above the chuck for clearance.
Crueby, yes to new tools that work :). However, in my case, if a new tool doesn't work, it may be operator error ;D.
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Thanks! Always interesting to hear what other people do for depth of cut - that's typical of the kind of cut I would make in that situation.
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Sure; my pleasure, Stuart. I did not mention that I did go very slowly cutting through slot.
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I completed the flywheel. It is concentric.
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A little more progress. I checked the cylinder bore before starting the piston. Much to my surprise, I had unwittingly left it at .450", when it is supposed to be .500". I re-chucked it in the 4 jaw, and after making sure it was concentric, I proceeded to turn the bore to .500.
I then worked on the piston to completion. Good tight fit in bore. It looks a little dark in color because I oiled it, and moved it back and forth in the bore. You will also note the piston shaft is rough looking, because, unfortunately it is :-[. Nevertheless, it will not affect function.
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Hi Bear, good to see the progress.
It’s an interesting looking engine. I downloaded the plan so I can follow along.
Coming along nicely.
MJM460
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Thank you, MJM. That is very kind of you.
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I was challenged by a very simple part, the 1/16" thick steam chest cover, because it was so thin. Had trouble figuring out how to clamp it in the vise starting out with 1/8" thick brass. Could not get it square, and i wanted it square and to size because the instructions say that the 4 screw holes in the cover are to be used as a "jig for the Valve Plate, Steam Chest and Cylinder Block".
I watched a good YouTube video last night, that showed using three 123 blocks in the mill vise for smaller items. Problem is that I have a smaller vise that would not work with the three 123 blocks. The video is from Joe Pieczynski. The portion that may be applicable starts at around the 16 minute mark. Did not know if appropriate to use a You Tube link here, but,it can be found by searching the above name on YouTube. The date of the video was yesterday. It is titled Machining a Model Steam Engine - Part 4 - Square Collets and Small Parts.
So, instead of the 123 blocks that were used in the video, I used my parallels with one upon which rested the thin plate up against the fixed face of the vise. The other parallel was used sideways to apply pressure to the thin part. It worked. (see 4th photo below)
Plate has been dimensioned squarely, and is next ready for drilling the 4 mounting holes. I did use a fly cutter for the 2 large surfaces.
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Hi Bear, My previous engines have been from bar stock, and I have found a good way to machine that cover is to leave cutting the part off the bar as long as possible. Use the rest of the stock plus a little on the end to clamp it down with the area to be machined all clear. It is so tempting to start by cutting off the required length, being sure of course to create as little waste as possible, but it’s not the best choice for the first operation. You have to always think about how you will hold the part for the remaining operations.
Once one side is machined, the technique is to put that face against the fixed jaw in the vice and work out the sequence to ensure that all other operations are referenced to that face in a way that ensures they come out square. Blue the reference face so you don’t forget which one it was.
Too late for this time, but the same ideas apply to almost everything you make from barstock, so I hope that it will help you for the next parts. Things that the experts do, almost without thinking about it, that I was fortunate to be taught early by my expert mentor. Not that I remember everything he has suggested, but I try.
Using that parallel laid flat to improvise a thin part vice looks like a good idea, I must remember that one.
And of course the thickness of the cover is not critical, so accurate thickness is more about practice and appearance than function.
MJM460
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I made mine out of 1/16" brass plate I bought at the hardware store. Two sides were parallel so that made it easy to get it squared to size. Then just drilled it to the exact dimensions needed and it bolted right on.
Jim
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Thanks, MJM. Good idea on not cutting to size at first. Appreciate your advice.
Thanks, Jim.
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Hi Bear,
I was challenged by a very simple part, the 1/16" thick steam chest cover, because it was so thin. Had trouble figuring out how to clamp it in the vise starting out with 1/8" thick brass. Could not get it square, and i wanted it square and to size because the instructions say that the 4 screw holes in the cover are to be used as a "jig for the Valve Plate, Steam Chest and Cylinder Block".
It is very difficult to hold something that thin flat in a vice flat but there are alternatives: If you want to mill the edges of a thin piece square you can hold it by the flat faces and use the edge of the vice against the smooth edge of the bar to square up the metal for machining the top face. In fact this method works for thicker bits as well ;)
Jo
P.S. I see you used a two flute cutter to mill the edges flat. If you have a four flute cutter you will get a better finish. Two flute ones are best for cutting slots
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Thanks, Jo. I do have 4 flute cutters; but, I generally use 2 flutes for aluminum. I should have changed it out. However, the finishes on the edges came out okay. On the other hand, the fly cutter did wonderfully on the faces.
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I used to dun Zee with the advice to "never remove a part from parent stock until it's absolutely necessary". This should be printed on each page of the paper you use to write out a machining sequence for your part before cutting any metal.
On another note, you may have fun doing something I did when building this engine. Mill another steam chest cover out of transparent plastic. It can be thicker than the brass cover if you can't find 1/16 sheet.
Use the plastic cover when running on compressed air so your audience can observe the motion of the valve; it makes explaining the operation of the engine much easier. Replace the plastic cover with the brass one when you want to run on steam.
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Thanks, Marv.
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I used to dun Zee with the advice to "never remove a part from parent stock until it's absolutely necessary". This should be printed on each page of the paper you use to write out a machining sequence for your part before cutting any metal.
On another note, you may have fun doing something I did when building this engine. Mill another steam chest cover out of transparent plastic. It can be thicker than the brass cover if you can't find 1/16 sheet.
Use the plastic cover when running on compressed air so your audience can observe the motion of the valve; it makes explaining the operation of the engine much easier. Replace the plastic cover with the brass one when you want to run on steam.
Bear,
Marv gave me this same advice...........which I followed. The plastic cover really shows off the valve action.............fun!
I also follow his advice about leaving a part on parent stock as long as possible. :ThumbsUp:
Jim
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Jim, it is tempting to use the plastic see through cover. Yes, I will heed the advice on the length of the stock.
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Finished the Steam Chest cover, and the Valve Plate. Now I need to figure out the best way to line up the Cover and Valve Plate holes with the top of the cylinder so they line up exactly. Don't have a transfer punch small enough (guess I could make one), and the cylinder is tall than my vise jaws. Suggestions welcome.
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If I understand correctly, the holes are drilled to clearance size on the covers, and you need matching tap size holes in the cylinder? What I would do is clamp the cover in place and use it as a drill guide. Put the clearance size drill in the chuck, cylinder in the vise, and adjust the table till the drill lines up with the hole. Power on, and lower the drill enough to start the hole, but don't go in deep. Then you can swap to the tap size drill and finish drilling, the spit left by the first drill will keep it from skating.
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You are correct, Crueby, that the current holes are clearance holes for what will be tapped holes in the Cylinder top.
Thanks. Good idea; but, I can't figure out how to clamp it and at the same time use the vise. Maybe, i should just clamp the plate on top the Cylinder directly to the mill table with no vise??
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That would work, and if the clamp blocks a hole just drill and tap the others, run in bolts to hold cap aligned for drilling the last one. One thing I have done a few times is clamp parts with a parallel clamp or two, and clamp the flat of the parallel clamp in the mill vise. Lots of creative ways, as long as it stays steady with the pressure of the drill.
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Thanks, Crueby.
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Next time try this technique...
Super glue the undrilled cover to the cylinder. Drill TAP-SIZED holes through cover and to depth in the cylinder. Remove cover by heating. Remove any glue residue with acetone. Open up cover holes to clearance size on drill press or whatever. Tap the holes in the cylinder.
You may want to make some inconspicuous witness mark on the inside of the cover so it can be replaced in the orientation in which is was drilled.
You know, just in case the holes aren't exactly symmetrically placed.
Obviously, this procedure works anywhere a feature must be attached with screws to some structure.
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Thanks, Marv. I was thinking of still using super glue, and then lining up the already drilled holes in the method described by crueby. I plan on figuring it out today, and getting er' done.
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Might be worth putting a mark on the inside of the cover so you know which way round it fits best ;)
Jo
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Thanks. Good idea, Jo. I did mark the outsides with a marker for doing the center cut outs in the valve plate; but, I will put something more permanent on the inside. I think that in a much earlier post, I referenced that the cut-outs and holes in the top of the cylinder were not properly centered. So, when I made the valve plate, I made the cut outs off centered to the same extent of the cylinder top. Of course, this will require consistent alignment for the screw holes.
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Well, I got it set up in the mill. It sure helps to brainstorm on this forum. I think the set-up will work. Off to lunch and then to tackle it.
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I ended up drilling 2 of the 4 holes while the clamp was in place. The other 2 holes were inaccessible due to interference between the drill chuck and the clamp screw. In line with crueby's post, I threaded the 2 holes and held the plate down with screws (had to use both plates due to the length of the screws).
Finished this portion. Next is to make the Steam Chest.
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I made the Cover, Steam Chest, Valve Plate and Cylinder the same exact dimensions. Then I drilled each one to the same exact required dimensions. Tapped the Cylinder. Then it was just a matter of bolting the sandwich together. No match drilling required.
Jim
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Hello Bear,
I've been in the shadows observing your progress and like what I am seeing. :popcorn: :popcorn: It is always interesting watching a fellow bringing another model out of the barn and asking good questions. Continue on with your project and stay inquisitive, its healthy....
BC1
Jim
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Thanks, Bearcar1 Jim. I appreciate the kind words. Yes; being inquisitive is healthy by keeping the brain active with regular workouts :).
Flyboy Jim, thanks for reminding me that I need to get the four 2-56 screws long enough to go through all 3 parts and thread into the cylinder.
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The machining seems to be going well so permit me to address another issue.
I notice that many of your close-up photos are out of focus. Depending on your camera, there are at least two ways to fix this...
Use the macro setting on the camera.
Back off from the subject and use the telephoto capability to zoom in so the subject fits the frame.
To be realistic, the steam chest and cover would be secured with studs and nuts, not long bolts. 2-56 "all thread" is available from Amazon...
https://www.amazon.com/Du-Bro-801-2-56-Threaded-6-Pack/dp/B0006O4HQS/ref=pd_lpo_21_t_0/137-0790995-9841221?_encoding=UTF8&pd_rd_i=B0006O4HQS&pd_rd_r=381c03f0-88f0-4b71-ace2-fa034ceac846&pd_rd_w=2k4qW&pd_rd_wg=TqZmo&pf_rd_p=7b36d496-f366-4631-94d3-61b87b52511b&pf_rd_r=XCK94Z6S13A83KHW52P5&psc=1&refRID=XCK94Z6S13A83KHW52P5
If you want the convenience of bolts you can Loctite nuts to lengths of this all thread. Once in place it will look like a nut threaded onto a stud but can be unscrewed like a bolt.
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Thanks, Marv.
As to the camera, I know what you are saying. I think that the focusing issue is recent, since I noticed that the shutter sound is not clicking as fast as it used to. I tried charging it, and it did not help. I am using the "close-up" setting, and have been. I will try different settings, and also try the zoom feature.
The all-thread idea is great; but, I think I can find the bolts locally and then cut down if necessary and then re-thread the cut area with my 2-56 die. Or, if the threaded portion of the bolts is long enough, I can make my own all-thread. If not, I will order from the link you generously provided.
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It could be an autofocus problem.
When the shutter button is pressed half way, most cameras show a small square outline on the viewing screen to indicate what they are focusing on. If that square isn't on the photo subject the resulting photo will be blurry.
All cameras have some means of overcoming this...
Aim the camera at some object at the same distance as the intended subject and press the button halfway and hold. Repoint the camera at the intended subject and press the button fully.
or
Manually move the square to be on the intended object (see manual for how to do that).
Lighting can sometimes affect the focus mechanism's performance. Ensure that there is a lot of light on the subject.
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Thanks, Marv for encouraging me to look into the focus issue. I think I fixed the camera issue, as I hope will be demonstrated by the attached photo. Somehow, the setting was moved from "Close Up" to "Manner/Museum".
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Thanks, Marv for encouraging me to look into the focus issue. I think I fixed the camera issue, as I hope will be demonstrated by the attached photo. Somehow, the setting was moved from "Close Up" to "Manner/Museum".
In my best Adam Savage voice: Well, theerre's your problem.
What camera are you using?
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That looks much better. Guess we have no manners in the museum.
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...
What camera are you using?
It is an old inexpensive Kodak. I have enjoyed it over the years.
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That looks much better. Guess we have no manners in the museum.
;D
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...
What camera are you using?
It is an old inexpensive Kodak. I have enjoyed it over the years.
So YOU are the one that bought one of our cameras! :LittleDevil: (I worked there for 30+ years, we invented the digital camera and did sell LOTS of digital cameras, but as a business line it never made any profit. Sold millions of inkjet printers, those lost money too. Sigh. At least I got a pension out of it! )
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I've never seen, much less held, a Kodak digital camera. A bit of searching dredged up this...
https://mashable.com/2012/01/20/kodak-digital-missteps/
which helps to explain why they were unknowns to me.
Regardless, to paraphrase Henri Cartier-Bresson... The best camera is the one you have with you when a photo opportunity presents itself.
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Great summary Marv. We saw over and over again that the top brass ignored and under funded anything that was not film based, they had blinders from owning a huge cash cow for many decades. There was also a big chemical products division, profitable, that was spun off since it wasn't film. Same for Sterling Drug, which included tiny brands like Bayer, that they sold since they didn't know what to do with it. Stupid, over and over...
Sorry for the diversion, back to the great build!!
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No photos today. All I did was square and size (except length) the rectangular Steam Chest to get it ready to align in the 4 jaw chuck to do the two round ends.
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Some progress today. Machined the aluminum Steam Chest in the lathe, including drilling the holes for the valve. Next step is to mill it out and drill the mounting holes, not necessarily in that order.
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Nice - some great quality parts coming along. Another step forwards!
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Thanks, Stuart. Not so sure about the quality; but, I hope it works well.
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Finished the Steam Chest (except surface finish ;D).
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Mounted the Steam Chest and plates to the cylinder block. Cleaned it it up on the mill. Now to make the valve, valve rod and nut.
Question: as to the valve, is the only critical dimension the fit between the valve and the valve plate?
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That is one of the few items where you want it to be able to lift off the surface so not important but you do want a good smooth finish on both surfaces. The nut should not bind in the slot but have as little play as possible, make sure it is threaded squarely otherwise that can tilt the valve and stop it sitting down onto the ports face.
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Thanks, Jason. Very helpful response.
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A very little progress here. My 1st attempt at the valve rod resulted in messed up threads (3-48) because I did not thread it correctly. After the 1st attempt at the valve rod, I did some wood turning, and today, I am back at the valve rod. Properly threaded this time, and it is now ready for the square end and hole on the mill.
PS: Clarity of photos is still not good. Might start taking the photos with my phone next time.
Also, I don't have a die handle for this size die, so I just turned it very carefully by hand.
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Hi Bear
Looks like you are coming along nicely with your engine.
It appears for the most part that your camera is focusing on the background of your shots. Maybe if you didn't try to get so close you might have better luck. On almost all of the pictures that I use on the forum, I crop them to show only what I want. So if you back up a little and everything is in focus then you can crop out what you don't want to show.
I use a free program Ifran View that does a good job (for me anyway) of cropping and resizing pictures.
Keep up the good work!
Dave
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Thanks, Dave.
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I agree with Dave about your focus point. Maybe experiment with the various focus modes.
I use a tailstock die holder for threading rods. Huge help. This is the one I have:
https://godshallscustommachining.com/products/die-holder?_pos=1&_sid=74d459d86&_ss=r
Plus the correct shank for your tailstock. There are others out there as well.
Jim
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Thanks, Jim. I was actually thinking of making a die holder.
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A very little progress here. My 1st attempt at the valve rod resulted in messed up threads (3-48) because I did not thread it correctly. After the 1st attempt at the valve rod, I did some wood turning, and today, I am back at the valve rod. Properly threaded this time, and it is now ready for the square end and hole on the mill.
PS: Clarity of photos is still not good. Might start taking the photos with my phone next time.
Also, I don't have a die handle for this size die, so I just turned it very carefully by hand.
Many cameras allow you to lock the focus by depressing the button part way. If yours allows this, try focusing on a larger object at the distance you want for shooting the part or whatever and locking. Now, move into the desired position for your shot and go for it. Good luck.
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Thanks, Alan, Jim and Dave for the camera tips. I will see what I can do. Probably user error that can be remedied with all the tips I have received in this thread.
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Happy Thanksgiving to all on this side of the pond :).
Had some time to finish the valve rod today, before the festivities. On to the valve. I did use one of my 3 jaw chucks (with modified jaws) instead of the 4 jaw because the way the 4 jaw lined up, it would have crushed a portion of the threads.
And by the way, the photos are better, thanks to all the tips I received here.
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Excellent!
:popcorn: :popcorn: :popcorn:
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Thanks crueby.
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Looking good. :ThumbsUp:
Jim
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Thanks, Jim.
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That's what I call sharp pictures.
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Finished the valve today. Next is the valve adjusting nut.
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Very nice work - great pictures. Coming right along!
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Thank you, Stuart.
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Finished the valve adjusting nut, and the valve seems to work properly. Next, I will be on to completing the exterior of the cylinder block.
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Looks great, getting close to first air tests?
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Looks great, getting close to first air tests?
Thank you. I guess I need to finish the cylinder before the air test, don't I.
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Looks great, getting close to first air tests?
Thank you. I guess I need to finish the cylinder before the air test, don't I.
Details, details... :Lol:
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Looks great, getting close to first air tests?
Thank you. I guess I need to finish the cylinder before the air test, don't I.
Details, details... :Lol:
;D
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Been a while since I did any work on the engine; however, I have been doing other milling and lathe work.
No photos today; because all I did today was the cylinder head without the holes. Next is to drill the holes, and line them up to the cylinder and drill and tap the cylinder.
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Some progress. Pretty much finished the cylinder assembly; except for an exhaust pipe and a little cleanup. Now to progress to the eccentric assembly parts.
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Although gradual, I have made some progress. Connected the connecting rod today. Turns nicely. I can feel some compression. May try to hook up some air for a little test. Need to tidy the screw that mounts the connecting rod to the flywheel. Next to move on to the eccentric rod.
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Looking good Bear. I too chose that engine as my second build.
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Getting close, very nice! Just looked up a video of one running (flyboy Jim's), very interesting eccentric motion on that engine. :popcorn:
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Thanks, Ronald and crueby.
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Looks like great progress!
Dave
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Thanks, Dave.
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Tried it out with some air. Piston pushed back with valve movement; however, I can not get the piston to move in (compression stroke) with valve movement. First of all, I think this should be doable at this point; please correct me if I am wrong, and I hope I am ;D.
If it should have movement on the compression stroke, any ideas on what went wrong?
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Two things I would check first (I've had both issues in the past). First, is the port on the valve face for the compression stroke being opened as the valve rod moves forward? It could be that the valve slider is not centered properly, or the slider itself is too long. To check, take the cover off the valve chest and turn the engine over by hand, and see if the port at either end is exposed and covered again.
The other possibility that comes to mind is if the port at the end of the cylinder that connects to the port on the valve face is blocked by the gasket. I had en engine where that was the issue, trimmed the gasket and it ran.
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Just looked back to earlier in the thread, noticed that there is a valve plate as a separate piece on the cylinder block. Check that all three ports are open, could be the one at the inner end is blocked by the gasket.
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Thanks, crueby. I did check, and the port was not visible when moving the valve forward, so I elongated the port and it now opens when the valve is moved forward. However, that did not make it work. Also, as a reminder, I have not yet made the eccentric. By the way, no gasket on this engine, at least not that I saw in the plans.
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Hmmm. Is the passage that leads from the port down to the end of the cylinder on that end lining up with the port in the valve face? Or could the opening into the cylinder be blocked by the cylinder cap on that end? Got to be a blocked or missing opening somewhere if the air is not getting through.As for the gaskets, unless there is a perfect mating surface on both sides, usually there is one between parts, the gaskets are commonly not shown on plans since they usually just show metal parts, and the gaskets are just made to match the shape/holes of the parts.When you apply compressed air, and move the valve, the piston is not moving - do you hear escaping air hissing from anywhere? How much pressure is the compressor supplying?
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Thanks, crueby. I did check, and the port was not visible when moving the valve forward, so I elongated the port and it now opens when the valve is moved forward. However, that did not make it work. Also, as a reminder, I have not yet made the eccentric. By the way, no gasket on this engine, at least not that I saw in the plans.
With the slide valve at one end of the throw is one port open and the other closed and then the same for the opposite port at the other end of the throw? I just looked at mine and as the slide valve is at one end, one port is open, the other is closed. Then as the slide valve is moved the other way both ports are closed for a bit and then the other post is opened with further movement to the other end.
Jim
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Thanks, crueby. I did check, and the port was not visible when moving the valve forward, so I elongated the port and it now opens when the valve is moved forward. However, that did not make it work
The risk in enlarging a port is that now that port could be opening while the opposite port is not yet closed. Then there is pressure on both sides of the piston. It is usually better to remove material from the offending side of the valve, without changing anything on the other side.
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You can check that the air passage is clear by removing the valve, blocking the exhaust port and the input port to the opposite end of the cylinder with a bit of modeling clay and then applying air. If the passage is clear you should be able to feel the air pressure on the piston.
It's conceivable, but, IMO unlikely, that there is a leak between the offending air passage and the exhaust passage. Air meant for the piston would escape directly into the exhaust before reaching the piston. Also, check for burs on the valve plate. A bur that lifts the valve as it moves could cause such a leak.
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Thanks for all the great responses. I got my work cut out for me later today (probably) where I will investigate all of the comments further. May also take some photos.
Now to answer some of the questions.
Crueby, there is air escaping from the exhaust opening on the opposite side of the air intake; but, does not affect the piston moving back toward the crank with even a little air. It is only the movement of the piston toward top that does not work, even with more air pressure.
Jim, I will certainly check for that, and report accordingly.
Ron, I will take a photo of what I did to enlarge the port. By the way, after that did not work, I also took some material off the piston to make it shorter on the same port side, in case air was not getting behind it. Did not help.
Marv, I will check for all that you have mentioned.
By the way, reluctant to show my ignorance; but, I need to research further to see how all these ports work in conjunction with the piston and valve movement.
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...
By the way, reluctant to show my ignorance; but, I need to research further to see how all these ports work in conjunction with the piston and valve movement.
It was one of my very first engines and I had the same question. It took me a while to puzzle it out and, to this day, the elegance of the slide valve operation still delights me.
When the valve is at its maximum extension, port A is exposed, and air in the steam chest can reach the A side of the piston. The bottom of the valve covers port B and the exhaust (E) port. This connects the B side of the piston to the exhaust. Thus, as the air pushes on the A side of the piston and moves it, the air on the B side of the piston is forced out the exhaust.
As the valve moves to the other side of its travel, these connections are reversed.
But what's really clever is to note that valve chamber (used to connect alternating sides of the piston to the exhaust) is ALWAYS OVER THE EXHAUST PORT. With air pressure inside the steam chest this means there is always a downward force on the valve sealing it to the port plate. Leakage is prevented even in the presence of wear.
There's another advantage to this slide valve. When a steam engine is shut down, whatever steam is still trapped in the cylinder will condense into liquid water as the engine cools. Water is incompressible so this liquid could block the piston motion at next starting of the engine and bend the connecting rod. This is why steam engines with piston valves, e.g. locomotives, have drain cocks on the cylinder and will "blow down" the cylinder before getting underway. With the slide valve, the entrapped water is pushed out of the cylinder and lifts the valve and can escape harmlessly out the exhaust port; no drain cocks required.
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Marv, thanks for the excellent explanation. Still planning on working on this this lather today.
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Marv, thanks for the excellent explanation. Still planning on working on this this lather today.
Here's a nice animation that may help your understanding...
[youtube1]https://www.youtube.com/watch?v=9NEm3PMHPyc[/youtube1]
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That animation was very helpful. Thanks.
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Crueby, I did find significant air escaping out the valve entry point outside of the steam chest. I tried to tape it up while still being able to manipulate the valve. Although the leak was limited in volume, it did not make it run.
I took it apart again to see if I could find something amiss other than what is readily apparent, as you will see in the photos (e.g. one of the port holes is not properly located on top). As stated in Marv's post above, the exhaust port is always covered which is interesting. Also observed was that the other 2 ports were open, one at a time.
Here are some photos.
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Something to check on your valve geometry - I looked back at the slide valve, and compared that to the valve ports:
(https://i.postimg.cc/nzyt1yYj/valve.jpg)
I can't tell from the pictures, but you should measure the max length of the recess in the bottom of the valve slider, and also the distance between the inner edges of the ports, as shown by the blue arrows. If that opening is longer than the distance between the ports, then you can have air pressure going from one end port all the way to the other, and also the exhaust port, all at once, which is no good.
Another thing to look at is how tight the adjusting nut is in the slot in the top of the slider. It should be a close fit, but not so close that the slider can't sit down tight on the valve face, there has to be some wiggle room on that fit. If the movement of the valve rod can cause the slider to lift from the valve face, then no power goes to the piston. Same for the fit of the valve rod in the lengthwise slot in the slider - that needs to be a loose fit to allow the slider to find its own level on the port face.
The fact that you had to lengthen the port on the one end is an indication that one or more of the valve port or slider opening dimensions is not correct - those ports should be symmetrical to each other. It may be that a better solution is to square up the corners of the steam chest opening to let the slider go farther to each end - its common to have to file those inside corners on the steam chest to square them off to give the slider room to travel. One thing I usually do is to make marks with a felt tip pen around the sides/top of the slider that line up with the ends of the opening on the bottom, and also make marks on the valve face to indicate where the openings of the ports are - then you can assemble it, with the top cover off, and move the valve and see if the ports are being covered/uncovered properly. Its a simple set of geometry, but it can be very touchy on having a dimension off just a little bit.
Chris
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Chris, thanks for your excellent post. I am going to have to think a little longer on some of your points. As to the movement of the valve over the valve face, it appears to be a good fit. Also, observing the valve with open cover reveals that the ports are properly exposed, one at a time.
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To start with you will need to remake your valve plate. The elongated opening will allow the air pressure push the piston the opposite end of the cylinder and that's all you'll get.
After that you can worry about the valve itself.
Eric
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I agree with EricB; that extra hole in the valve plate is just plain wrong. Like Eric, I suspect that it allows air to reach that side of the piston regardless of the valve position. Why did you put it there?
Also, in your first picture, the two holes in the cylinder that admit air into the bore aren't placed symmetrically wrt the exhaust hole. That doesn't match the print although, since those holes are angled, it's hard to say from here whether it's a problem.
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Thanks, Eric and Marv. The valve plate hole was elongated only after I could not get it to work because the port was not sufficiently exposed when the valve was in the forward position. As to the ports in the cylinder, they are at equal distances from the ends of the inside of the cylinder; but, as you observed, Marv, the side that is giving me issues did not end up in the correct location due to the angle that I messes up somehow. I thought it would be ok at the time, and now I am having doubts.
PS: I think I will try another valve plate at this time. How should I line up the plate port hole in relation to the off-angle port hole that goes in to the cylinder?
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Bear, the ports in the valve plate should be done as close as possible to the plan dimensions. The way the valve plate sits on the recesses in the cylinder in is not critical, as long as the recesses dont span two ports.
You mentioned that the passage into the cylinder was a little off, as long as the opening at the cylinder end is correct, that wont matter. When testing, if the piston is right up against the end of the cylinder then no air can get out of that port and behind the piston to move it. When the conrod and crankshaft are connected, the piston should stop short of the end so that would not be a problem, but it could happen if testing without things connect up.
And I agree with the other guys, that extra hole is a big problem, needs to be remade. We all have to redo parts, good practice!
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Thanks, Chris. I will make the new plate. Won't be difficult to do. I did make the piston a little shorter to make sure the air was getting behind it. I do note that it wants to work, and it may be something to do with the eccentric not hooked up for the valve timing.
In any event, I really appreciate all the troubleshooting here. Makes me think (brain exercise :)).
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Update. Well, although I did not make a new valve plate, I did fill the excessive portion with JB Weld. That did not fix it; however it was a good start. I next made a new valve rod for a better fit in the steam chest opening. That did not work
Finally, after noticing that jut too much air was coming out of the cylinder head and guide where the piston rod fits. I took it apart again and notice the hole was extremely oversized :-[.
I made a new head and guide with a better fit to the piston rod. It now works in both directions, compression and exhaust, although it is a bit rough. I think I am satisfied for now with the belief that it will wear in for smoother action. Now it is on to fabricating the eccentric portion.
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Glad you found the main cause, those other things are likely lesser causes, but till all the biggies are fixed not much changes.
:popcorn:
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Thanks, Chris. You are correct. Everything helped. Plus I now have more experience. Oh, I neglected to say that I also re-made the crankshaft for a better fit to the bearing.
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Hi Bear, good to hear that you have identified the worst problems. It’s always good to be able to move forward. Even if a little more refinement is eventually required. You will get there, I am sure.
MJM460
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Glad to hear that you've located the problems. Besides getting the engine moving, this exercise has given you a good feel for how well things have to fit in order to work.
For the future, remember that a bit of soapy water brushed on joints/bearings/etc will quickly locate leaks.
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Thanks, MJM and Marv. It is in fact a relief to be able to move on now.
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Finally finished the build; well, kind of. Still have some cosmetic work to do; but, most importantly, I need to get it to run. I did have it running for a little while. It did not run well, and required high air flow. Made adjustments to the eccentric and the valve with no ability to make it run. When it did run, it only ran in one direction, clockwise, with the "reverse lever" in the position where the handle was pointing away from the cylinder unlike the photos.
Tired of messing with it for now. Will try again later.
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In an attempt to understand what may be wrong, I attempted to put my version of the engine in the same configuration as you show in your first picture.
It looks to me to be a problem with the orientation of the reversing slider. Compare the angle of the channel in which the slider slides in your version versus mine. Also note the angle of the cam follower-the part that drives the slider.
As well, it appears that the slot in your reversing quadrant isn't as long as mine. That may be part of the reason that the slidert channel doesn't angle as mine does.
Try to get your engine configured as mine shows and see if that works better for you. You may have to remove the retaining screw from the reversing quadrant and clamp the quadrant into position to get the slider tilted as far as mine is.
Good luck and let us know if it helps.
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Thank you, Marv. I see what you are saying; however, I do have more room to tilt the slider more. The problem I encounter when I tilt it more is that the sliding block locks up in the slider at one end or the other, making it impossible to function. I do appreciate you taking the time to troubleshoot my engine. Is it possible that my eccentric rod is too long causing the binding?
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Thinking the eccentric rod may be a little long per previous post, I tried moving the base of the column and the base of the cylinder away from each other by loosening he mounting screws for each pulling apart and tightening. There was some but little movement. It ran well then with very low air pressure. Nevertheless, there is still a significant problem in that it will only run with the reverse lever in the position shown in the photo below. Looking at the front of the engine (crankshaft side), the crankshaft spins in a clockwise direction. Actually, in the picture, you can tell that it was running when I took it.
The reverse lever is a bit rough as can be seen, and I had to make 2 arcs because the first one was too high. One I get it running right, I may make a cleaner looking one. I don't have a rotary table. Use a pin for the arc and roughing with the mill and some filing for the rest of it.
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Hi Bear, I am glad to see you still at it. I was beginning to wonder where you were up to.
You did not say what you mean by the slider locking up at one end of the slider. Is it possible that this is due to the valve rod or the valve reaching the end of the available travel. May I suggest that you remove the steam chest cover, bolt the steam chest back in place and and see what is happening in there as you turn the crankshaft. (You will soon see why studs and nuts are recommended for holding the steam chest in place.)
It seems to me that the eccentric rod is not too long if the connection to the valve rod does not hit the end of the valve chest.
If the end of the valve rod does not hit the outboard end of the steam chest, it may just be that the valve is not at the right place on the valve rod. It’s worth observing whether the threaded section of the valve rod allows the valve to be adjusted to the right place when the slider is at the midpoint of its travel (and the lever set to the point where the valve travel is minimal and the valve should cover both steam ports). May need to thread a bit more of the valve rod. Or the valve rod could be too long, so it hits the outer end.
I am sure that you will have it working soon and be able to celebrate.
MJM460
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Thanks MJM. I appreciate your comments. Hope all is well with you.
I have checked the valve move moment without the cover plate. Maybe if I am more patient with the adjustment, I will get there. It does appear that possibly the length of the valve rod may be an issue.
As to the "locking", the sliding block is binding heavily at one end or the other of the travel in the guide, if the guide is tilted at too much of an angle.
Actually, I have been celebrating :cheers: the fact that it runs very well with very little air pressure at the position of the tilt lever as shown in the photo. One of these days, I will figure out why it won't run out of the position, but I am for now leaning toward the theory that the rod (or something) may be slightly too long. But for now I will be pleased with it for what it is worth. It is very neat to see it operate :)