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Why am I building this model engine? Terry last year enquired about a reasonably priced model he could build and I suggested the "Clarkson Steeple" Engine. When he brought his set of casting he sent me a PM suggesting that thought it would be a good idea if I made mine in tandem with his so that I could provide clues as to how
not to do the bits on his engine. Terry has made an excellent start to his engine over here: https://www.modelenginemaker.com/index.php/topic,10540.0.html
So lets start with a bit of history of this model design: in 1932 Mr R Wood exhibited his model of the "High Pressure Steam Table Engine" built in 1840 by Murdock Aitken & Co, Glasgow at the Model Engineer Show for which he was Awarded the "Borneo" Cup . He made his model to a scale of 13/16" to a foot. I am not sure why he chose this scale :noidea: but he may have limited it to what he could turn on his lathe so he chose to scale the model accordingly.
(http://lister-engine.com/coppermine/albums/userpics/10007/Original_model_engine_1932.jpg)
One of the well known suppliers of sets of Locomotive Castings "Clarksons" was so impressed with his model that they purchased the rights and after a number of years set about marketing the casting set and this is where the confusion sets in: Clarkson in their catalogues called this a "Steeple Engine". Steeple engines normally have their heavy cylinders on the floor and their crankshafts above them which this doesn't :thinking:
The castings for this engine is currently available from Blackgates in the UK for a very reasonable £220 but you will also need a few few pairs of bevel gears as well. As Blackgates are now the supplier of Clarkson model engine castings they have continued the Clarkson name of "Steeple Engine" but seem to think it is now to a scale of 1" to 1' :headscratch:
I may regret this but I plan to make a 1:1 scale of Mr Wood's model engine :) from the Clarkson castings, so I am calling it what Mr Wood called it a High Pressure Steam Table engine ;D
Jo
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Clarkson have provided two different sets of drawings for this engine over the years. The later set is known to have bits missing and duplicates of bits :toilet_claw: Blackgates do sell a set of drawings but I am not sure which set they supply. For myself I have parted out the later drawings then realised that a part was missing and then had to add it to my binder :Doh:
I found in a book a set of original engravings from which I think Mr Woods built his engine:
(http://lister-engine.com/coppermine/albums/userpics/10007/Original_etching_1.JPG)
(http://lister-engine.com/coppermine/albums/userpics/10007/Original_etching_1b.JPG)
(http://lister-engine.com/coppermine/albums/userpics/10007/Original_etching_2.JPG)
(http://lister-engine.com/coppermine/albums/userpics/10007/Original_etching_3.JPG)
These show that the Clarkson drawings have a few more simplifications which may (or may not ::) ) be included in my build.
Here is the starting point:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4848.JPG)
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4849.JPG)
Now what is really, really simple that even I can't get wrong :thinking: And :facepalm: I think I am short of a casting.
Jo
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So, are you missing the casting of the base? I couldn't identify that one in your pictures.
This looks like it will be fun! I'm enjoying watching Terry's build too! Lookin forward to it Jo :) :popcorn:
Kim
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You are most likely right about the original builder basing his scale on what he could swing as the flywheel will only just fit within a Myford size gap.
Looks like the eccentric strap may have gone mossing or someone has cut the two bolting lugs off and left you a GM ring?
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There are a lot of new and interesting casting sets for engines appearing in the last few days :) not my thing (I'm the strange kid playing on his own in the corner with fuel injection etc.) however I enjoy following the builds. Keep them coming :ThumbsUp: :ThumbsUp: :wine1:
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That little tin with the bevel gears in it is causing a bit of envy here :P Looking forward to your build Jo. :popcorn: :popcorn: Terry
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You are most likely right about the original builder basing his scale on what he could swing as the flywheel will only just fit within a Myford size gap.
Was 13/16" scale actually 20mm. Are any of the other original modellers sizes consistent with this 'metric', or is itjust a coincidence. Regards, Paul Gough.
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Yes I also thought the eccentric strap was missing but that odd bronze ring has the correct casting number on it :headscratch: I found something more suitable:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4853.JPG)
Off we go then :paranoia: First up the base casting. I need to be able to hold it so I flattened the underside and made the "sticky out bit in the middle" so that it had square sides:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4850.JPG)
Now I can hold the casting so time to turn it over and find the centre. It seemed obvious to use the hole in the centre:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4851.JPG)
Then I checked with the sides and found the hole was off set :facepalm:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4852.JPG)
Then I started playing try to calculate the missing hole dimensions :wallbang: The distance out for the crankshaft bearing (29.4mm) is missing as is the distance for the mounting for the water pump (centre 43.15 mm). Before drilling all the holes for the tapping sizes:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4854.JPG)
The top of the casting was 4.8mm above the main flat area so first job was to take the tops off and then to cut the slots for the four columns:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4855.JPG)
Lastly milling the surface for the crankshaft bearing housing:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4856.JPG)
The main flat surface of the casting is still well over the 3.18mm but I am going to leave that for now and write on the casting that it still needs to be taken down. I will tackle this later once I have a suitable mounting arrangement :)
Jo
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Jo,
Really pleased to see you doing another build, complete with your ideas, improvements and suggestions to builders. Will watch with interest. I have been struggling to start anything over the last 12 months.
Keep looking at part done Redwing. I want to get on with it.
Colin
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Thank you Colin,
Yes a lot of people have found the challenges over the last couple of years with Covid has made them struggle with being able to focus on making models and sadly I am one of them :(
The drawings for this one are a bit "lacking" in places :disappointed:
Jo
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Great to see you back in the Shop and up to your usual standard Jo - including the thought process :whoohoo:
Will follow you progress and hope to learn :cheers:
Per
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Thanks Per :)
From the base to the table is those four columns :thinking: The provided castings have less flutes on them than the original etchings that Mr Wood copied.
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4858~0.JPG)
The first bit of fun was trying to work out all of the various bumps and lumps on the column and making it legible. I the end I drew it out double size on paper:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4859~0.JPG)
I marked up the square section bits and then went back to look at the original etching again :thinking:
(http://lister-engine.com/coppermine/albums/userpics/10007/Original_pillar.JPG)
The central fluted area seems to have about 18 flutes and the flutes do not have dimples on the end :thinking: This means that is going to need to be a separate bit so the cutter can go passed the end of the taper.
On the drawing above you can see a red outline this is my intended shape for the central section. Initially I considered using steel but was concerned that might blunt what is going to be a rather small milling cutter. Aluminium is out due to corrosion when in contact with steel. My larger diameter brass stock would quickly become depleted if I raided it for 400mm of the stuff. Then I found a 7ft length of bronze hex :headscratch: That must have been kicking around since a few years BD the amount of patina on it. Having cut 4 pieces of 100mm off of it, lets see how it turns:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4857.JPG)
A bit sticky but not too bad, just a long tedious job to do :ShakeHead: Hence I am in for a coffee trying to get my enthusiasm up and eyeing up my cross stitch thinking how nice it would be to finish that off today ::) I could look out a means of cutting the taper :noidea:
Jo
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I do not want to start anything taxing at this time of the day :ShakeHead: So I have opted to look at preparing to cut that taper. So many books talk about offsetting your tailstock :hellno: This is how I propose to achieve the same:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4860~0.JPG)
I will be using a boring head mounted in a ER32 toolholder in the tailstock, to provide an offset centre, thus:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4862~0.JPG)
You may have noticed a second centre in the first photo. I am not sure if a pointy centre will be able to provide sufficient pull over without a bit of rubbing so I have also made a ball centre just in case.
The second challenge will be cutting the flues parallel to the taper which is important otherwise they will get shallower towards the thin end :facepalm: With a dividing head comes a tailstock. If you look at the larger one of these two you can see it can be offset to enable tapers, the little one I will be using doesn't :disappointed:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4863~0.JPG)
All is not lost as I will be adding some packing under it to provide the required offset ;)
I think I am ready to go in the morning :)
Jo
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Hello Jo,
So glad to be able to follow another of your excellent build logs and fully agree with your sentiment about getting back into the saddle to machine again and I have yet to start due to gardening taking precedence.
Mike
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Thank you Mike, please to see you are following along. Yes I agree the garden is very time consuming at this time of the year.
To begin the day all four columns were turned to fractionally over same diameter as the widest part of the taper:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4864~0.JPG)
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4865~0.JPG)
The length of the centre section is within 0.05mm of each other so that should do :)
The taper cutting set up is simple: Mount between centres, move the tool up to touch the outside diameter on the wide end, move to the other end and wind the tool out by 1.5mm, then move the boring head toward the tool by 1.5mm and check it touches. This should nearly set up the taper but a small adjustment will be needed as by moving over the tailstock end of the piece also moves the headstock end over so always check dimensions as the turning proceeds:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4867~0.JPG)
Initially I tried using the pointed centre on the boring head but it was not giving a good finish :disappointed:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4868~0.JPG)
So I swapped it for the ball support:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4871.JPG)
Other than loosing one of my balls in the swarf :facepalm: all went well. At the end of the day four tapered columns:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4874~0.JPG)
At this point I found I did not have in stock the intended size ball end cutter I hoped to use for the flutes :rant: Time to finish off that cross stitch :-\
Jo
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Looking great Jo!
The one time I cut flutes in a column, I didn't have a ball cutter, so I took a normal square end end mill the same size, and tilted the mill head over 45 degrees, and ran the columns under it with the part centered under the cutter. Ran the cuts so the side of the cutter was touching the part first, and the tip dragging along behind. The angled end cut a nice rounded shape just like a ball end mill would.
:popcorn: :popcorn: :popcorn:
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Thanks for that idea Chris I might need it ;)
Jo
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Another option if you want to keep the moths under wraps is to grind up a simple single point tool and use that to cut the grooves at the side of the column not the top a bit like gear cutting, would also save packing the tailstock to height and the cutting edge is moving a lot faster than the almost dead middle of a ball nose so should give a nice cut.
Did you drill with a standard ctr drill or one that gives a trumpet shaped hole? They are supposed to be better for this but I've not tried one.
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Thanks for the idea Jason :) . I think packing the tailstock up (cutting at the top) is going to be much easier than trying to offset it sidewise during the cut on the side in order to get the flutes parallel.
I only have standard centre drills.
Jo
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There is an easy way, shout if you decide to go down the side cut route.
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Geometry/aesthetic question: do you mill the flutes parallel to the side, or make the cut depth slightly greater at the fat end to keep the lands between the flutes parallel?
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They should be slightly deeper at the bottom otherwise you end up with the bits inbetween getting too narrow. I'll dig out the formula later and I think I have some images showing how it's done. Also they do not have to be semi-circles you want say a 4mm dia cutter for a 3mm width flute so it's more of a scallop.
It's debatable if it would notice on a part this size and I'm sure whatever Jo does will be an improvement on the rather soft ill defined castings. I did it for the much larger Otto langen and if Jo gets round to doing her "big Willey" then that would probably need it.
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have a look at this and the next page, I drew one out in CAD
https://www.modelenginemaker.com/index.php/topic,7162.195.html
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have a look at this and the next page, I drew one out in CAD
https://www.modelenginemaker.com/index.php/topic,7162.195.html (https://www.modelenginemaker.com/index.php/topic,7162.195.html)
Which post numbers? I am not seeing the column at that link, its a long thread to search through.
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This one https://www.modelenginemaker.com/index.php/topic,7162.msg153641.html#msg153641 ::) Its the land width that should be kept a constant ;)
Yes the groove is not a true semi-circle but elliptical which can also be achieved by cutting on the side of the cutter like Chris mentioned :)
Jo
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This one https://www.modelenginemaker.com/index.php/topic,7162.msg153641.html#msg153641 (https://www.modelenginemaker.com/index.php/topic,7162.msg153641.html#msg153641) ::) Its the land width that should be kept a constant ;)
Yes the groove is not a true semi-circle but elliptical which can also be achieved by cutting on the side of the cutter like Chris mentioned :)
Jo
Excellent - thanks!
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The discussion of fluted columns runs for over two pages starting at or before the top of the one in my link
Jo's 18 flute one with a 2.4mm cutter
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The skewed cutter trick is an occasional lifesaver. I made this clack valve for an unusual direct mounting onto a boiler barrel (having a reinforcing piece inside).
Although the curved face is theoretically slightly eliptical, it bolted up as machined, with no fitting required. (It is not my workshop, and that ancient [Archdale?] mill has since been scrapped).
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For jobs like this, where the flutes are 'visual, and don't have to be geometrically accurate, I have simply taken an end mill of the right diameter and freehand ground the end to form a ball end mill. Even better if you can use a broken or blunt cutter, and make something useful from it!
Probably not an acceptable solution for you precision guys, but I'm from the 'coal board fitter' side of the spectrum!
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Luckily I have found a 3mm ball nosed cutter so I am going ahead with that one :)
I first jacked up the tailstock by half the difference in the taper diameter. Mounted the column in the dividing head chuck making sure to only hold it on a bit so to allow the piece to flex and checked the top cutting surface is flat:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4875~0.JPG)
:)
Time for some dividing head calculations:
This dividing head is 40:1 and I need 18 flutes :thinking:
18 times 40 = 720 so I need something divisible by :facepalm: what am I up to if I use an 18 hole dividing plate then all I need is to move forward 40 holes = 2 full turns plus 4 holes. What could be easier :ROFL: Off we go:
Start with a 0.1mm cut:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4876~0.JPG)
:thinking: Looks like plenty to go but lets go round a bit...
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4877~1.JPG)
The depth looks even:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4878~0.JPG)
That looks even, round the whole way:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4880.JPG)
A bit more depth and :rant: :wallbang: :toilet_claw:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4881~0.JPG)
Don't you hate it when that happens :Doh: I have just cut a spare/replacement in time for a strong coffee :disappointed:
Jo
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Did you think about mounting it between centres instead of the light grip in the chuck and letting the workpiece flex?
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If you noticed the first photo of the piece showed it on a centre but when I added the drive dog I found it was hit by the milling machine chuck at the closest end. The three jaw chuck has a fraction more clearance :)
Jo
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Jo, do you have a spin indexer as there is less chance of miscalculating the turns. Every other hole of the usual 36divisions would work out well
Or go for 20 flutes which is just two full turns of the div head handwheel
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Many ways to skin the proverbial Feline .... and the
Extra Spare looks fine :ThumbsUp:
Per
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Jo, do you have a spin indexer as there is less chance of miscalculating the turns.
:headscratch:
I recall selling you my spin indexer as I didn't use it. :old:
Jo
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Unlike you to only have one of something ;)
I thought I had seen you using an indexer but hay have been a vertical one. Do none of your dividing heads have a direct indexing facility, I know some do.
If your cutter is getting a bit close to the chuck/collet then a simple extension could be made, just a bit of bar with a hole in it and grub screw to clamp onto the column's spigot
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All of my dividing heads have the ability to do indexing: The standard indexing ring count is 24, which allows you to do 2, 3, 4, 6, 8, 12 and 24 divisions. Of course the columns need 18 flutes to keep me on my toes.
Thankfully the cutter and its tool holder has plenty of clearance for cutting these flutes :) Out of interest that little ball end cutter is an FC3 cutter and Clarkson do a rather nice FC3 cutter holder which provides a bit of an extension that can be used if needed. Personally I prefer the DA holders which are much smaller than the Clarkson ones. You may have seen me using the DA extensions on other pieces, they can be picked up for about £5 each and often come with a free collet ;).
Jo
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That's not a bad flute length for an FC-2 cutter, I'm moving away from them now as the carbide ones can be picked up for not much difference in cost from the likes of APT and they tend to all have 50mm overall length so reach and visibility is better, smaller sizes tend to have 4mm shank not 6mm and you can also get them with 4 flute so feed rate can be doubled.
I've seen the Clarkson adaptors but not had need to use them as I don't use a Clarkson chuck.
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Standard milling cutters are just under 50mm long. The FC3's were always considered to be cheap disposable items, with good edges that held well and were forgiving, normally they turn up at about £1 each in their sealed packets. I have a very scary to use 1.5mm ball nosed milling cutter in carbide, as you know small carbide breaks easily :paranoia:
Here are a pair of standard Clarkson FC3 holders (metric and an imperilous one ::) ) they fit into any tool holder that is also able to hold the same size Clarkson milling cutter. You can also see an FC3 cutter made for my BCA.
Back to flute cutting ::)
Jo
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Hi jo
Is the ball nose in the first picture a carbide end mill it has long ftute length the ones i used to use were very short and a 3mm shank
held them in a mazak chuck in a er 11 chuck could run at 3500 rpm to cut a groove part way round piston rings insides to 400mm dia
it was just as well it was in teflon compound materials or they would have been very fragile that long flute don't know how that would have lasted.
John
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Hi John,
Yes it is. I think high speed, well supported and cutting plastic would be increase its life expectancy before it goes "twang"
One column fluted.... just getting focused ready to do the next one :)
Jo
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Initially I started with a cut 0.2mm deep:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4885~0.JPG)
I repeated at 0.35mm deep:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4886.JPG)
It is really difficult to see how deep the scallops are :ShakeHead:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4887.JPG)
So I took it to 0.4mm deep and called it deep enough. A few coffee breaks to aid my counting on the dividing head: move sector arm to touch back of plunger, move the plunger to sector arm, plus one turn, plus second turn and let the plunger go into hole. Cut next slot. Move sector arm, move plunger up to arm, 1, 2, cut. Making sure that both full turns are done (this time ::) )
Those horrible cutter marks will be cleaned up with a round needle file when I feel the need for something easy to do ;)
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4891.JPG)
That's enough excitement for today :paranoia:
Jo
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Thats a LOT of cranking, counting, moving.... :ThumbsUp: :ThumbsUp:
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Certainly an improvement on the supplied castings
Will you attempt to reuse the capitals or cut new from stock? Expect you will keep the bases due to the shape of the cut out
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Very nice fluted columns, Jo! :popcorn:
Kim
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Kinda like the mill finish on the flutes. But I guess smooth fluting is preferred by the aesthetes? :ROFL: :popcorn:
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Having done the easy bit ::) it took a while to work out how to do the next. One key requirement was to find some sort of design that would get rid of the horrible idea of securing the column to the base with a nut inside the hole in the column. Unsurprisingly I intend on reusing the bottom of the column and having checked my metal stocks I decided the square top section will also be reused.
So if I was going to reuse parts of column I need to machine it. First try to hold it on the square to put in a centre:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4892.JPG)
:ShakeHead: The square on the small end won't go through. Then try holding it on the taper :paranoia:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4893.JPG)
:ShakeHead: That's wobbling all over the place. Give up it needs to be between centres. First find a centre relative to the hole in the side and the corners of the square:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4894.JPG)
Having done both ends now I can drill in the centre having first made sure it was mounted vertically under the centre drill::
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4895.JPG)
Finally I can turn the end of the column so that it is actually round:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4896~0.JPG)
Finally four columns that have their supporting surfaces ready to actually start doing the machining of the bits I want:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4897~0.JPG)
It always amazes me how long it takes to prepare a job before you can actually start (and that is without the Robins wanting to play fetch all the time ::) )
Jo
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Hi Jo,
What is that gizmo in the third picture where you are finding the center, with the round base and the two things sticking out the top, one looks like a clear sight of some sort??
Chris :headscratch:
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Hi Jo,
What is that gizmo in the third picture where you are finding the center, with the round base and the two things sticking out the top, one looks like a clear sight of some sort??
Chris :headscratch:
Optical centre ( center ? ) punch :
https://www.amazon.com/Flexbar-Optical-Center-Punch/dp/B001C1DC6K
Haven't got one. No idea how they work :headscratch:
Dave
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This little beastie :naughty: Optical Centre punch. I've had it for years. Its showing its age.
I have also made it a single tool holder because the standard double can be a bit bulky.
Jo
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Interesting tool - thanks for the details!
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The Veritas one should be available State side from the woodworking suppliers, that's the one I have and it's a bit smaller based than Jo's. Don't use it as much now that I have the DRO so no need to mark out but it does get used when I am marking out.
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Grizzly do one:
https://www.grizzly.com/products/grizzly-optical-punch-set/h5781
I bought one of those. It seems pretty decent quality. I've not used it much, only played around with it a bit. I'm sure they must be available from plenty of other sources as well.
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I am getting very concerned about the difference in size between the original tops of the columns and the drawings size :paranoia:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4904.JPG)
The great news is that the way I am doing these columns means they can be corrected later if required.
I discovered why yesterday one of the tops of a column caught: it had a hard spot :ShakeHead: So try again and this time I am using a machinist's jack to further discourage the piece from moving:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4906.JPG)
Before ruining these castings I need to clean up the hole I want to keep:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4907~0.JPG)
As you can see one of the holes has a wonky bottom :facepalm:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4908~0.JPG)
So that needed a bit more of a file. With the hole in place I can now look keep it in the correct position while I write off these castings ::)
Jo
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RE: Optical Center Punch
You can make one: Search for: "making optical center punch" on google or YouTube.
(No, I haven't done it myself yet.)
--ShopShoe
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I tried making one. It works ok, but you need a lot of light to see the bottom of the hole through the acrylic - though Jo's version has a much taller upper bit, which might act as a better light pipe. I too don't use it much since fitting DROs on the mini mill.
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I've ruined the columns :facepalm: All those nice flutes have gone:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4910.JPG)
I have turned them round and the only important measurement is just above the square base which is 12mm diameter. The remainder has been turned to get rid of the casting marks and left at a standard size (standard as far as I have a collet that fits ::) ).
The next problem is making sure all of the holes are in the same position relatively to the square base.
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4911.JPG)
The one on the far left is 2.4mm down from the top of the square section so I am going to turn them all to match before the next bit :paranoia:
Jo
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I've ruined the columns :facepalm: All those nice flues have gone:
Jo
Yup! They get swept away before you have time to notice ..... ::)
Dave .. who is assailed by the small black ants at the moment ... >:(
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I'm guessing that you are aiming after the biggest common denominator on the measurements on the four of them (if that is the correct way to describe this) .... certainly curious to see how you solve this :ThumbsUp:
Per
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Thanks Per,
I have parted off the bottom of the CI column castings and bored them 8mm so that the bronze casting fits into them. I then turned the bottoms round and parted off the lower extension piece:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4913~0.JPG)
Then I faced the lower section off leaving it over height by 1.6mm, so the bottom square section is 16mm high not the 14.3mm shown on the drawing, this can be removed later if required. The reason for leaving this is I want to be able to thread this part of the column rather than leaving it clear:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4912~0.JPG)
Why because I foresaw this problem:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4914~0.JPG)
See that little nut hidden inside the hole? That is a 4BA one and there is no way that you can tighten it up with a spanner :ShakeHead: I think the best you can hope for is to reduce the nut A/F to 5BA size and leave the thread 4BA:
(http://listerengine.com/coppermine/albums/userpics/10007/IMG_4915~0.JPG)
But even so with a full hex spanner you cannot go the required arc between nut flats :Doh: Most of my double ended bi-hex spanners are off set so they do not fit :disappointed: The last resort is the bi-hex on the end of one of my open spanners:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4917~0.JPG)
It does fit but I am not convinced I will be able to get it tight so I am changing the design ::) No longer will it have four very sexy studs in the base plate :-\ but it is about to have those lovely threaded holes drilled out and I will be countersinking under the bottom plate so that I can use countersunk :facepalm2: screws to secure the bottoms of the columns onto the base plate and the nuts might be left slightly looser than I would prefer :-X
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4918~0.JPG)
Jo
-
Time to start using up some odds and ends from the scrap bin:
The square ends off of the 5A's conrods were used for the square washer:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4919.JPG)
Separate bits for the rounded section. First undercutting well before rounding with a file:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4920.JPG)
I did consider making a form tool but decided I could do it just as well by hand. So a set of washers for the bottoms of the columns:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4921.JPG)
Now I need to do the same for the top :)
Jo
-
The square sections from the top of the old castings have been bored to fit the bronze columns, leaving me with some very useful bits of Cast Iron off cuts :)
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4922.JPG)
The lower section has been turned up in a single piece:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4923.JPG)
Which can go on the top of the column:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4925.JPG)
Giving us 4 columns:
(http://listerengine.com/coppermine/albums/userpics/10007/IMG_4924.JPG)
And that is where they are going to stay for now ;)
Time to look at the Table. First we need a datum and that will be the bottom so mount it as flat as possible and check with a level:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4927.JPG)
Then a a quick skim round but taking off as little as possible. This still is not enough :ShakeHead:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4928.JPG)
Another 0.3mm and
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4929.JPG)
Ready for a bit of casting fondling :pinkelephant:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4930.JPG)
:thinking:
Jo
-
Those columns would not look out of place on the Parthanon and are a good improvement over the cast ones :)
-
Yup, like the look of the machined columns much more than the cast ones.
-
Beautiful columns, Jo! I couldn't agree more - so much better than the original cast ones! :popcorn:
Kim
-
Very good Jo, this is going to be a real machine temple. Great!
Greetings Michael
-
Looking good Jo. :popcorn: :popcorn: :ThumbsUp: Terry
-
Excellent! :popcorn: :popcorn: :popcorn: :popcorn:
-
Hi Jo,
Another build thread I have started to follow, brilliant work there mate, :popcorn:
-
Thanks Guys, sorry for the slow response but the local area lost all power last night and they didn't seem to be in rush to put it back on :disappointed:
I think I have a way forward with the table. It has its challenges not least one of the corners which is missing a bit of the top thin surface :ShakeHead: And I have noted that there are lots of hard bits on this casting :toilet_claw:
Jo
-
I have found another drawing FEATURE :rant:
The distance between the two holes for those long side connecting rods is missing from the drawing :disappointed: The connecting rod Yoke is shown as 1.86" or 47.25mm. This looked wrong on the casting......
Looking at the Piston rod crosshead it shows 2.25" or 57.15mm between the centres of the two side connecting rods...
Back to the casting :thinking: 57mm seems to match up with the centre line of the slots that are already in it. I'm going with the 57.15mm and will change the Yoke to be the same :)
This may also account for why I read somewhere that one builder was complaining that the side rods hit the side of the exhaust where it goes round the cylinder.
Jo
-
OOoohbah Doobah!! I like those columns Jo, Very nice work and vision in making them. :DrinkPint: :popcorn: :ThumbsUp: :ThumbsUp: :ThumbsUp:
Jim
-
Hi Jo, this is coming together and looking great.. bar stock modelling is so much better than castings usually and it is difficult getting scale sand for the casting process ?!!!
Willy :popcorn:
-
bar stock modelling is so much better than castings usually
Careful :stickpoke:
Round here we know Castings are sexy :embarassed: :pinkelephant:
Jo
-
Round here we know Castings are sexy :embarassed: :pinkelephant:
Jo
I've heard about these sadomasochist types :o
-
Your mind works in very mysterious ways Jason :facepalm2:
Jo
-
I decided that I was unhappy with the bottom of the table as there was 0.7mm offset so I remounted it and tried again ::) Before using a wobbler to centre on the underside of the casting:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4933.JPG)
I didn't trust that so time to check with a pointer:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4934.JPG)
:thinking: slightly tight but there is nothing I can do about it, so drill some holes
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4936.JPG)
Counter bored those hole to fit the top of the columns and clean up the slots for the connecting rods:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4937.JPG)
And not forgetting drilling the holes for the cylinder:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4938.JPG)
:thinking:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4939.JPG)
:thinking:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4940.JPG)
Time to measure and decide what to take off of where:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4941.JPG)
Lunch time :P
Jo
-
Really shaping up well, a great little steam temple building! :popcorn: :popcorn: :popcorn:
-
That really is a splendid looking engine :praise2: :praise2: :wine1:
-
Thanks Guys :)
Measuring the top surface of the table I found it was 6.4mm thick so I turned the table over and having remounted it in the machine vice used the cylinder holes to find the centre and made a little dimple ::) This was then used to centre the casting in a four jaw chuck:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4942.JPG)
The top of the table needs to be counterbored 35mm diameter. It is much easier to do this on a lathe than on a milling machine:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4944.JPG)
Back to some more measuring :paranoia:
Jo
-
Last bit for today, having worked out the required height of the lands for the two side frames as being level with the top of the table I could mill the top flat surface. Then I found the two surfaces to mount the side frames was both too narrow across total table width (the outside mounting holes would have broken through) and each too narrow (11mm rather than 12mm) so I adjusted the mounting hole spacing accordingly.
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4946.JPG)
One set of holes for the valve spindle pivots blocks is still to do but as drawn the part will not fit on the corners of the table where it should go :headscratch:
That's it for today:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4947.JPG)
I am not going to start the filing etc.
Jo
-
Very very impressive Jo and a great build so far
-
Thank you Mike,
Sorry nothing to show for today the nice man turned up with my first load of UK Government funded winter heating and I have been busy clearing it ready for the second lot :cartwheel: Hopefully some more swarf tomorrow (or more chainsaw chips :noidea: )
Jo
-
It’s delightful and ornate. Will make for a very attractive engine for sure.
-
Thanks Stuart :)
I added some pads under the main holes and have secured them using JB Weld and while that sets I have added some odd 5BA screws:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4952.JPG)
:thinking: I don't like those 5BA nuts on there :ShakeHead:
Then I decided to tackle the cylinder. First problem how to hold it. I decided on holding it from the top on a face plate so I needed to take a skim across the tops to get it flat:
(http://listerengine.com/coppermine/albums/userpics/10007/IMG_4954.JPG)
Now to mount it on the faceplate. First hold it via the hole in the end and clamp it on the plate:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4955.JPG)
Then check it is actually square :thinking:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4956.JPG)
Twirl it around check everything looks even all the way down the cylinder:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4957.JPG)
Time for the chicken stick and to face the end.
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4958.JPG)
At this point I had a senior moment :old: :-[
Jo
-
I like all your improvements so far Jo :ThumbsUp:
I do hope that the Senior Moment isn't going to cost more than time to rectify ....
Per
-
Thanks Per,
I do hope that the Senior Moment isn't going to cost more than time to rectify ....
It all started when I spotted this:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4959.JPG)
Then I looked at the Cylinder casting and realised I was already under the smaller of these two measurements. Finally (after about an hour) it dawned on me that the cylinder sits on a 7.2mm "mount". So while there is two different measurements on the Side frame, one of which is clearly wrong :disappointed: The height of the cylinder needs to be the distance to the top of the fancy bit on the side frame minus the 7.2mm. There is still a bit to come off the top but the 96mm is about right :) So I could face the bottom and finally start the boring bit:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4966.JPG)
The core down the centre of the casting ran true and the boring bar isn't (yet) finding any hard bits. There is plenty of time left to find something :-X
-
You may have noticed that no swarf was made yesterday :ShakeHead: Instead I was convinced that I should take the bits I had already made (plus the Rectilinear) over to see my supplier, who promptly regretted selling me these castings. We had a little trip out to his workshop and I dug out his OTHER set of these castings which he claims he had forgotten about :old:
I then discovered why I had been talked into going for a visit ::) I came away with a Sanderson Beam engine (complete with metal worm :o ), one orphan and another set of castings that are under close guard in case I try working out what they are :noidea:
Jo
-
Hi Jo.
The Gardner replica looks to have been well engineered so far judging by your picture. Are there any bits missing?
:cheers: Graham.
-
I haven't been allowed near it yet. :disappointed: The only thing I had spotted was the larger of the two gears is not there. Why do you think it is a replica? :headscratch:
In the mean time I'm still making chainsaw chips :toilet_claw:
Jo
-
I haven't been allowed near it yet. :disappointed: The only thing I had spotted was the larger of the two gears is not there. Why do you think it is a replica? :headscratch:
In the mean time I'm still making chainsaw chips :toilet_claw:
Jo
A slight misunderstanding, obviously one of mine. It is, after all a half scale replica of the Gardner size 0 circa 1907.
Meanwhile the inspiration from which the range of Gardner horizontal engines came from is nearing completion.
The Robinson HA Oil engine, in 1/3rd scale. Circa 1895.
:cheers: Graham.
-
You have posted pictures of those jowitt castings before so should know what they are
Yes Grahams HA is looking good, waiting for mine to drop on the mat along with another little project
-
A slight misunderstanding, obviously one of mine. It is, after all a half scale replica of the Gardner size 0 circa 1907.
Thanks Graham, knowing the history of this orphan I had my suspicions that you might mean "someone" had been copying your castings :o
Jo
-
You have posted pictures of those jowitt castings before so should know what they are
But they weren't Surus' then. In the meantime there was tales of them having been sold to someone else :hammerbash: until they reappeared about 6 months ago at which point someone has been trying to wrap him round his little trunk until it finally worked and I was sent to recover them before Eric's workshop gnome stole them again. I think something is missing :thinking:
Jo
-
Back to the boring bit... I had noticed that the cylinder was getting rather hot while boring it. On inspecting the carbide tip I found it had lost its edge :wallbang: I turned the tip round and did another bore and concluded that it was too hard for this cheap Chinese carbide tip and it was time to dig out a Sumitomo tip. This cut through it like butter and left a rather nice finish :)
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4973~0.JPG)
The late start in the workshop I am blaming on Dave visiting (and the Robins/Chaffinch needing multiple feeds before they would let me out). While Dave was visiting I spotted that when I JB Welded on the square washers on the bottom of the column they had not gone on square :ShakeHead: Time to warm them up using my heat gun and turn them slightly :-X
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4974~0.JPG)
With the cylinder finally bored I have taken it off the faceplate and am looking to mount it on a mandrel. Why is it that every time I make an engine it has a different sized bore :facepalm: Having looked around I found a piece of 28.5mm steel which was a tight fit but not ideal. The best I could find was a piece of aluminium which is 28.8mm or I can make another 2 washers for my 25.4mm mandrel :noidea:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4976.JPG)
:thinking: I'll think on it, there is no rush. After all I am retired so there is all the time in the world so I need to make some more workshop time in my busy schedule and decide which to make before then ;) .
Jo
-
Ok so I wasted a couple of hours in the workshop :shrug: In the end I went back to my first plan and made a couple of washers
So ready to actually try to do something tomorrow :wine1:
Jo
-
The orphan look quite interesting with a side block with both inlet and exhaust valves ( or have I missed something completely :toilet_claw: )
I went to the opticians today to pick up my new distance and reading glasses. Both were to the distance prescription, copy paste error ::) ::) This will be corrected free of charge but i have to go to the next town again.
-
Hi Roger :) I think that is the inlet but I am likely wrong. Graham is the man who knows all about Gardners.
First thing this morning I milled 1mm off of the top of the cylinder. Having retightened the nut on the mandrel it is now set up between centres on H and has had the bottom of the cylinder milled to 47.2mm square. I then started milling the port face to find it was too hard for the HSS cutter I was using so had to change over to a carbide. This meant that I no longer knew the cutting height so had to check using a feeler gauge against the known height:
(http://listerengine.com/coppermine/albums/userpics/10007/IMG_4980.JPG)
I'm just about to mill the two top 'ears' before I work out how to do the trickier bits on this cylinder :thinking:
Jo
-
The orphan look quite interesting with a side block with both inlet and exhaust valves ( or have I missed something completely :toilet_claw: )
Hi Roger.
That’s the inlet valve chest. One valve does air and the closet to the camera does the gas. Both operated by a single rocker arm. The engines speed is controlled by an inertia governor probably best described by the accompanying video. The exhaust is carried under the front of the cylinder. Commonly known as a 3 valve gas engine.
https://www.youtube.com/watch?v=rhACUBzEGB4
:cheers: Graham.
-
The two top vertical surfaces have been taken to width and then it was time to check, check and triple check the position of the three 12BA screws :headscratch: that are used on the model to secure the two side frames.
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4983.JPG)
In the end I decided where looked right on the side frames and drilled appropriately but I suspect using the side frames as a drilling template may be more reliable.
The port faces are much easier to do if you can see what you are doing so I first put some marker on the face:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4984~0.JPG)
Then I had to work out where to put the stud holes for the cover. The drawings suggest 12BA :o I think 10BA nuts look better:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4987.JPG)
I have also moved the bottom two nuts in from where the drawing shows because that is how the original etching is. Drilling commenced and then I realised :Doh:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4985~0.JPG)
Some idiot has been in my workshop and hit the abs/inc button on the DRO and it has off set :toilet_claw: Time to fill those:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4986~0.JPG)
before redrilling :)
Now for the really challenging bit :thinking:
Jo
-
Wooops :wallbang:Jo, but seems a good fix to repair
Mike
-
Thank you Mike :)
Now for the new to me experience :thinking: I decided to start by milling the top of the exhaust way so that the outside was circulair and it had square edges:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4988.JPG)
Then I used the pointer to find the centre of the exhaust way. I found it was 1mm lower than on the drawing - this is not a problem. Before milling the grooves I decided to look at the cover. A piece of 1mm thick would be easy enough to roll into a circle but would not provide much to secure the exhaust flange on to. A piece of 1.6mm thick would be harder to roll :thinking: :thinking: Then I spotted a piece of tube which was a slightly smaller diameter which could be opened up to fit :whoohoo: So a 12.7mm wide piece was sliced off and faced.
Now to start the new to me bit :paranoia: I have calculated that the wide groove has to be 2.5mm deep but decided to start with a 10mm wide slot all the way round:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4991.JPG)
By doing this I can now mill on just one side of the cutter when I take the slot to width, rather than full width which tends to push the cutter away from the centre line. A spot of lunch then for the really exciting bit :noidea:
Jo
-
Mill either side of the slot to leave the slot 2.5mm deep and wide enough so cover fits:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4993.JPG)
Then mill 4.5mm deeper for the exhaust way, only to find :o
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4996.JPG)
:thinking: :paranoia: :thinking: Keep going... Square up the corners of the top slot:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4997.JPG)
Drilling the holes through to the valve face was fun :paranoia: The one at the front I could see, the one at the back needed a mirror:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4998.JPG)
The ring was split and cut to length using the "sticky tape method" to get the length right:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5002.JPG)
It will need screws in the corners to hold it down but not today :wine1:
Jo
-
Great to see that you still are progressing and making fine parts Jo :cheers:
Per
-
Thank you Per, it is nice to see someone following along :)
Fitting the screws was a bit of a challenge. The Stainless tube I had chosen was a piece of hardinium welded stainless exhaust and my drills did not like it :Doh: Then drilling into the cylinder without breaking into the bore was a bit :paranoia: To make it even more exciting I had to hold it in place with a clamp to get it to sit tight against the cast Iron while I drilled and tapped it:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5004.JPG)
Time to find the centre and drill the four mounting holes:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5006~0.JPG)
And I am pleased to say that having opened the holes up to the correct size :facepalm: it fits:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5009.JPG)
Now to work out how to hold the top cover as they seem to have forgotten to provide a chucking piece :noidea:
Jo
-
A real adventure to do that exhaust passage! That must have been an interesting bit of coring on the mould for a full size engine like that. Does look more interesting than a big pipe wrapped around the side though.
:popcorn: :popcorn: :popcorn:
-
Others are following, just not sure I should comment :-X
Funny enough the question of cores for a cylinder like this came up on my Unreal thread elsewhere, it's a fairly simple sand ring supported at one end by a core print that is an extension of the central port and at the opposite side but a print that forms the hole in the exhaust pipe stub.
(https://www.model-engineer.co.uk/sites/7/images/member_albums/44290/908278.jpg)
-
Neat, thanks for the diagram!
-
Thank you Chris :)
While looking at the top cover I have just found another drawing FEATURE :ShakeHead: The drawing shows a double step under the cover, if you do it to this drawing you will find that the steam passages on the outside will break though beyond the 35mm surface and "vent" to fresh air :toilet_claw: The easy answer is it needs the Cylinder register to be 1.6mm long rather than the 0.8mm shown on the drawing and to ignore the 35mm diameter.
I know why it was drawn this way: The original etching shows a gap round the underside of the cover and you can see the studs. But on that one the steam ports enter the cylinder further down. We have to drill the long holes :paranoia: down from the top and the distance means it will have to go in vertically as shown. I could possibly plug them and then go in with a tee slot cutter :thinking: Na, much easier I'll add a slightly wider diameter boss at 42mm but keep the main register that little bit longer. Which will mean it still looks like the engraving :)
Jo
-
If the castings you are using, plus the ones you just acquired are original Clarkson castings, they must have been rotten patternmakers and founders! Not too good as draughtsmen either. I hope Blackgates have sorted things out for their.current production.
-
I'm following too Jo, enjoying every bit, but relieved to be working on something else at present. :thinking: Excellent standard as usual :praise2: Terry
-
Thank you Terry, I hope this helps (You might want to delay drilling the three holes to screw on the two side frame until later than I have ::) )
Hi Richard: Clarkson went out of business years ago and it took Blackgates decades to finally be able to acquire the rights to the designs and be able to sell their castings. The guys at Blackgates had garage loads of stuff to sort out last I spoke to them about the Clarksons stuff.
I was pleased to see that they had made this set of castings available again at such a very reasonable price. There is nothing I would particularly complain to them about this design but I will document any 'features' I find as I go here on the forum so others can find them. I am sure once this one is done they will point perspective builders here so they can understand the opportunities and pit falls :facepalm2:
A friend is making one of the Clarkson inverted engines and that has lots of interesting features to keep him entertained :naughty:
Jo
-
The Draughtsman also produced a revised drawing that does away with that "gap" so they are not all bad just depends which you decide to work from and there may even be more revisions now.
Jo you could always make that 1 1/8" feature "lolly pop" shaped with a bit out the side to cover the passage
-
Yes you are right Jason the TRACER when they updated the drawing changed the underside of the cover. It is a shame they failed to follow standard drawing office practice and to mark up the drawing to provide the revision and details of what had changed. :disappointed:
Jo you could always make that 1 1/8" feature "lolly pop" shaped with a bit out the side to cover the passage
You do like to make a simple job difficult :stickpoke: Can't say I have ever seen a full sized one doing that.
Jo
-
But full size CAST the passages so you are unlikely to see it 8). Your cylinder is DRILLED & MILLED so has to be worked around. It's only a bit of rotary table work.
Difficulty to me is working with these drawings and sorting things as they crop up, with the number of "features" it would be less complicated to redraw in CAD based on measuring the actual castings and sort then there
-
But full size CAST the passages so you are unlikely to see it 8). Your cylinder is DRILLED & MILLED so has to be worked around. It's only a bit of rotary table work.
Can't see the point of milling a fancy boss under the cover when you can just turn the boss round on the lathe, to fit it into the round cylinder bore :headscratch: No one is going to see the underside of the cover and a round boss will work just as well in a hole with a cut out for the steam to go through. You seem to be making things more difficult than necessary maybe it is to justify having a CNC milling machine :noidea: . If you really wanted to make the port come out a little bit down the cylinder you could add an additional plate on the casting but I am not going to do that either :hellno:
Some of us are retired so we don't have as much spare time as you workers :disappointed: I used to get so much more model engine redrawing time when I went to w**k :old:
Jo
-
You still have the round boss to locate the cover in the bore and keep things concentric. The one in my drawing is the second larger dia one and maintains the gap to fully expose the studs.
A 1 1/8" round one won't fully seal the port. If you try and close the port off with an enlarged diameter completely round boss then you cover up the studs, minimum dia would be to the green line
-
Thank you Terry, I hope this helps (You might want to delay drilling the three holes to screw on the two side frame until later than I have ::)
Jo
Jo, I shall be delaying lots while you make progress and I watch and learn ;D Terry
-
I'm still following along and trying to understand the exhaust passage stuff :) :) :ThumbsUp: ::) :wine1:
I can deal with simple mushroom valves, two stroke ports are complicated, steam valse and valve gear :paranoia:
-
Hi Roger, it is not as difficult as Jason is trying to make it out to be :stickpoke:
Think normal slide valve: Three ports, middle one is for the exhaust. The exhaust normally just comes out as a flange fitting at 90 degrees to the port face. :)
We can't stick the flange out at 90 degrees on this engine as there will be two side rods waggling about and the two side frames all in the way. The answer is to pipe the exhaust round the back and put the exhaust flange fitting on there. The channel I just cut with the cover provides the 'pipe', or exhaust way, I still need to add the flange to that cover ;)
Jo
-
To save you anymore misunderstanding Roger, my comments yesterday were not even about the exhaust passage around the cylinder so not sure what Jo is poking at. :headscratch:
However what Jo is doing and what I have just done on the Real is trying to replicate a passage that would have been cast into a full size engine buy the use of a core. At our sizes it would be quite fiddly to try and do it that way so we have to use other methods to get the exhaust steam from the port to the outlet on the opposite side of the cylinder.
-
Holding the cover by the upper surface the bottom was turned flat:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5010.JPG)
Then we can turn first the top surface that the 8 mounting studs/nuts act on before turning the centre boss. As I am going to hold this cover on that surface in a collet I can also drill and ream for the piston rod:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5011.JPG)
And finally drill for the gland:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5012.JPG)
I then held the cover in a collet, turned to diameter and took the lower face down but thought better of it and turned the cover back round and finished off the fancy shaping while there was plenty of metal to grip on in case I found a hard spot :paranoia:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5013.JPG)
Back in the collet to turn the bottom register:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5015.JPG)
And making sure it fits:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5014.JPG)
I checked this before I added the 44mm diameter under cut under the cover. I did consider taking the undercut in a little bit more but the positioning of the steam ways comes out to 40mm, the same diameter as the 8 studs and the cover is only 46mm diameter. I think it works ;)
I need to turn up the gland before I drill any more holes :thinking:
Jo
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Wow. More like sculpting than machining...lovely work, Jo. :popcorn:
-
Thanks :)
I am still recovering from the show but it is time to make some more swarf. First find a bit of scrap-bin-ium, mount it flat and find the centre:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5095.JPG)
At the lower end of the side frame is a round decorative hole which is a nice 27mm diameter so I have made a bush to fit into this and the clamp goes through the hole in the centre. It also acts as a pivot so I can line up the casting and decide on the position of the top mounting hole:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5096.JPG)
With the top and the bottom of the side frame securely mounted I can now look at the slot. Looking at the drawing other than the width there are no dimensions :disappointed: The engraving shows the slot goes up to the point that the curve matches the curve of the side frame. I have dropped a washer there and the same at the bottom :thinking:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5097~0.JPG)
Now I can drill two 6.35mm holes for clearance at either end of the slot:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5098.JPG)
The slot is 5.5mm wide, but I am going to first cut a 5 mm slot then open it up after:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5099~0.JPG)
After a strong cuppa and I have changed that cutter for a slot drill :Doh:
Jo
-
I've found a nice new carbide 4mm three flute cutter so I decided to mill the centre of the slot out with that.
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5100.JPG)
I took this slowly and shallowly because I wanted the cutter to cut a true line. Even so you can see the ridges where the cutter moved slightly sideways in the slot in front of the 5.55mm cutter which is here on power feed doing a single cut taking 0.8mm off of either side:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5103~0.JPG)
Before moving the side frame I milled the bottom. I also remembered to take off the bottom clamp afterwards so you can see the big pivot mounting that was hidden under the clamp:
(http://listerengine.com/coppermine/albums/userpics/10007/IMG_5106.JPG)
And when we turn it over it looks :disappointed: horrible:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5107.JPG)
But that is not a problem we can sort that out shortly ;)
Time for the second one:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5108~0.JPG)
I am pleased to report having put the big pivot clamp in place the top has lined up :whoohoo: Off we go again :wine1:
Jo
-
Great info and to see that you're making progress Jo :ThumbsUp:
Looking forward to see the next steps :cheers: :popcorn:
Per
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Thank you Per, the next steps ;)
Second frame up:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5109.JPG)
All the same machining was done on this one. Then both were turned over and the back was faced on the sliding surface and behind where it attaches to the cylinder.
I then chose to mill the bottom to size so it matched the width available next to slot on the table and between the two stops:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5113~0.JPG)
The a quick check on the model:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5114~0.JPG)
There is still lots to do on these but I need to make the tie bar so I can look at if I need to adjust the backs of the frames or the location on the table for the 16 10BA holding screws studs :).
One note: These side frames did not have much spare on them :disappointed:
Jo
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Hi Jo, more great progress.
I always admire the way you find a way around all the difficult bits of these unusual projects. Every post is informative.
It’s a very interesting looking engine.
MJM460
-
Thanks MJM
Work continues on the side frames ::)
I forgot to drill the three holes for the bolts to secure the side frames to the cylinder:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5117~0.JPG)
Then I got my old shaper box out and used it as a mount for my jig while I drilled the 8 holes in the bases of the side frames:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5118.JPG)
Trying to fit the side frames to the table showed that a bit more machining would be needed to allow the nuts to be tightened up against a flat surface:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5119~0.JPG)
So a quick skim with a 3mm milling cutter:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5120.JPG)
Thankfully it all goes together:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5122~0.JPG)
To secure these I'm going to have to make some very small fasteners :Doh: Thankfully I got away with drilling those six holes in the cylinder as they line up :whoohoo: But I am delaying tapping those 12 BA threads until after I mill the slots in the top of the cylinder :)
Jo
-
Still following and enjoying your build and description Jo :ThumbsUp: :cheers:
Per
-
Thanks Per,
Its times like this I remember a talk I gave many years ago now about making my own 12BA nuts and bolts. But with this one there the additional pleasure of the matching studs :facepalm2:
Jo
-
12 BA is around M1.4 which I use in the injectors, so managable. I get a little nervous tapping M1. Still following along :ThumbsUp: :) :wine1:
-
Thanks Roger, and I am still avoiding making studs :-X
The bearings to fit into the side frames were made out of a piece of 16mm bronze. They need two flats opposite each other ::) so time to use the dividing head again:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5125.JPG)
Check the fit:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5126~0.JPG)
Part off and:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5127.JPG)
Another bit done :)
Jo
-
I'm interested to see the method you use to make studs. I've got a load to do, big ones in comparison, 4,5 and 6 BA, stainless steel. I know I could just thread them full length and part off, but it doesn't seem right somehow.
-
Thank you for the education Jo :ThumbsUp: Looking forward to getting back to my engine once the bikes are done. Terry
-
Thanks Guys, Terry I hope this is a bit more useful for you.
There is a drawing feature on the cross head >:( If you add up the bits that are supposed to go inside the two slide bearings you will find they add up to 0.6mm too wide to fit in the gap :disappointed: The only measurements you can adjust are highlighted below:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5130~0.JPG)
I've reduced those to 1.6mm each and it fits :whoohoo:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5132.JPG)
Now for the fun bit the taper. It needs to be just under 20mm long from the narrower section so I have marked that on the piece. I then loosened up the top slide, wound it back to the end of the taper which will need to measure 9.5mm diameter and wound the cross slide in so that the 3mm profiling bit touches the bar. Having found a spacer of the required thickness to provide me the correct taper, I then wound the top slide fully in, squeesed the spacer between the tool & material and tighten up the top slide. We are now set up for the correct taper for this item:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5134.JPG)
Having turned up a bit of the taper a quick measurement to check it is long enough and adjust the position of the SADLE if required.
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5137.JPG)
Both sides done:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5139.JPG)
I hoped to hold it in a 5C square collet to mill either side:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5142.JPG)
But the collet is not true to its slot >:(
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5143.JPG)
Another piece of quality Chinese tooling :ShakeHead:
I had just set up to do the sides another way and a salesman phoned up :wallbang: There is nothing worse when you are in the zone and someone phones up trying to flog you something and yak, I always loose my focus on what I was doing and have to walk away. It is so frustrating :rant:.
Jo
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I see what you mean, and thats annoying, but wouldn't it be good enough for what, after all, is a visual feature?
You seem to have come across a fair number of drawing errors. Are you using Clarkson drawings, or are they the ones currently marketed by Blackgates?
-
I see what you mean, and thats annoying, but wouldn't it be good enough for what, after all, is a visual feature?
The space between the two slide bars is 70mm and with that extra bit makes the crosshead with the bearings 70.5mm so it is too wide for the gap = it will be jammed solid and will be unable to slide up and down with the piston rod :ShakeHead:
These are original Clarkson Drawings, of which I have two different ones which do not admit to their date/version etc :Doh: I have no idea what Blackgates are doing in the way of drawings.
Jo
-
Also make sure you use the Conrod yoke drawing with the wider spacing not the one on the metricated drawings as that is a lot too narrow, might have suited the short crosshead you posted the other day that has gone AWOL
-
The space between the two slide bars is 70mm and with that extra bit makes the crosshead with the bearings 70.5mm so it is too wide for the gap = it will be jammed solid and will be unable to slide up and down with the piston rod :ShakeHead:
These are original Clarkson Drawings, of which I have two different ones which do not admit to their date/version etc :Doh: I have no idea what Blackgates are doing in the way of drawings.
Jo
Yes, I understand the bit about the cross head as drawn being too wide, but I was talking about your plan to hold the cross head in your square collet to mill the sides down to thickness.
-
Very true Richard: The little bit its out is only a visual surface on this piece.
:thinking: I could go back to the original way I intended on doing it but I am already set up for another method :noidea:
I'll sleep on it :)
Jo
-
You could loosen the pin on the 5C block and just hold the work true as you tighten the collet then original plan will work.
Now if only you had kept that indexer you could use the 1deg holes to set the job true then just rotate 180deg :embarassed:
I'd probably make use of the central hole to hold it on the CNC rotary table then the flats and the rounding of the central boss can be done in one setting
-
The connecting rod cross head was then mounted in a sub vice and centred up:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5144.JPG)
I first tried milling behind the piece :Doh: Then realised it was worth doing the front first:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5146.JPG)
And after the back:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5147.JPG)
Then off to the rotary table to round the centre:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5148.JPG)
I am sure Jason will explain to us where you have to be careful if you try to do the two flats on the rotary table ::)
You can see there is a little bump between the two curves:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5149.JPG)
A couple of rubs with a file and these are gone. Then use the Foredom to remove any milling cutter marks:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5150.JPG)
So it is not lost (stolen by the workshop gnome :-[ ) best put it into place on the engine:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5151.JPG)
There is a second cross head that I really should do before going on :thinking:
Jo
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What no buttons :LittleDevil:
Yes having it on just a central arbour like you do there is a risk of the work rotating so a bit of thought first to prevent that may help. Such as screwing the work through the central hole to a block than can include a stop at the rear. Also using CAD to get the exact point where the flat meets the boss can help save that little bump.
-
it is indeed an elegant engine :) :) :ThumbsUp: :wine1:
-
Beautiful looking crosshead, Jo! :ThumbsUp: :popcorn:
Kim
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Thanks Roger and Kim,
The valve crosshead is much smaller and more fiddly. I initially started making it from 5.5mm square steel but then realised the original engraving shows the centre section slightly taller so started again using 6.35mm square. It is the same as the other crosshead except:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5154.JPG)
I decided to play it safe and supported the end while cutting the taper. Then there was not enough to securely hold it:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5155.JPG)
So I made an additional holding block so it would be more secure in the vice.
The two drawings show the middle section of this crosshead as different lengths. I chose to make it 34mm (rather than either of the original drawings ::)) by scaling up from the engraving.
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5156.JPG)
Jo
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Looking great! :popcorn: :popcorn:
-
Enjoy to see the fine parts and progress you make Jo :ThumbsUp:
But I need to some more of the parts it matches up with, before my imagination will create a functional picture ;)
Per
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As long as you have material left to file, no harm - no foul. :popcorn:
-
Note for Ray ;)
I've just started roughing out the connecting rods and thought I better check that original reported error that the connecting rod as draw was too long....
Having measured the model and checked on all the dimensions, if the connecting rod is left at the 33.34mm ( 1 5/16") there is going to be 2mm of gap under the bottom of my table for the connecting rod yoke. So it should not hit as drawn :ThumbsUp: The report that it is going to hit the main bearing at the bottom is also suspect: There should be 17mm between the bottom of the yoke and the centre line of the crankshaft so the cap of the main bearing plus its oiler needs to be a maximum of 16mm.
And as I am about to make the long connecting rods I thought I better check their lengths as well. Initially I thought the mid point was a bit high but the cylinder stuffing gland overlaps the bottom of the slot in the guide. The calculated mid point is mid way between the top of the stuffing box and the end of the slots :)
What was I doing :thinking: Oh yes turning a long square bar round without a fixed steady ::)
Jo
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The reported problem may well depend on which drawings are used as the bearing height differs between the two
-
Its only 1.6mm difference so would just squeeze under. The original person who reported the error was reporting over 6mm of interference.
My columns are still 2mm over height in case other "features" come to light ::)
Jo
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I mentioned turning a piece of square round ::) This is it:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5164.JPG)
Its for the two long side connecting rods. Having got sufficient down to 8mm (by turning a bit, pulling another bit out, turning that bit down, the next job was to mark the length of the centre barrel section, its half and its quarters:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5166.JPG)
Pieces where held about 25mm short of the centre section and it was turned to 7.9mm - on both rods. Then the rods were moved out so that the quarter lines were at the collet, the top slide moved over so that it cut 0.4mm radi over 25mm and that cut:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5168.JPG)
That was blended into the centre section with a file. Then the other 3 ends done at the same top slide setting. Then time for the next 1/8 of the length with the top slide set to take off 0.5mm and finally a "nit more and take it down to 4.76mm blending the tapers each time:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5169~0.JPG)
It is easier to see the taper with the two rods together:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5170~0.JPG)
The problem with blending the tapers with a hand file is it causes marks which then have to be removed during polishing:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5171~0.JPG)
Yes I am polishing it now while there is plenty on the ends to get hold of :) But there is more to do and I don't want to rush it so I will return to it tomorrow afternoon :thinking: Not forgetting that I have to use the emery in two directions at 90 degrees to each other not just the easy one of rolling over to get a polished smooth surface.
Jo
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:headscratch: I don't seem to have remembered to write up last month's stuff. Oh well no one noticed so I'll sneak the next bit in ::)
The crankshaft is supported by two split bearings held in place by two blocks. The casting blocks supplied are not anything like what was on the original etching so I have made some alternative castings:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5185.JPG)
Each of the new castings have been made long enough so that they can be parted off to provide both the bottom and the cap:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5186.JPG)
And as you can see the holes that were used to keep the two bars parallel while silver soldering were drilled in just the right place so that they can now be used for the two mounting studs. They can also be used with two countersunk screws through them for the boring bit. First they need to be slotted together:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5187.JPG)
These are a nice friction together and once together they can now be set up for making the hole:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5188.JPG)
However not today :ShakeHead: because I have to get on and finish the Vincent otherwise it will never get done :facepalm:
Jo
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:headscratch: I don't seem to have remembered to write up last month's stuff. Oh well no one noticed so I'll sneak the next bit in ::)
Not quite so - but I have no right to demand it from You + you could have other priorities that has taken over, for one reason or another ....
Per
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Pleased you are still following along Per :) .. between you and me: I've got the side rods ready to be taken to length, the piston and its rod are done and connected up ... the short connecting rod is done as is the crankshaft turning. I haven't done the crank but it is on the list before I finish off the side rods as I need to check all the lengths then I plan to make the ends of the side rods ;)
Jo
-
The other day I had realized that I hadn't seen an update in a while, just figured you were out enjoying the summer weather or taking Surus for bike rides. Great to see the progress again!
-
Hello Jo,
the bearings look a lot better. They are very similar to the original motor.
Do the upper parts still have the attachment for the oil cup?
Michael
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Or as Jason said - you were likely out harvesting the goods from your garden! That's kinda what I thought.
People have lots going on in their life, so I always want to give them time to do their other hobbies without expecting moment-to-moment updates if they don't want to provide them. Some people do, and some people don't.
Glad you just didn't get around to posting and it wasn't anything more serious!
Always enjoy seeing your updates! I learn a lot from how you attack your castings. Thank you for taking the time to post.
Kim
-
Good to see you back on it. Just be carful with this fabrication of castings lark, you may become addicted :Lol:
-
I'm still following in the background and trying to find time for model making, especially when the mountains are calling :) :) :wine1:
-
Thank Guys, a few of the other bits I have found under the swarf:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5190.JPG)
Before I move on to boring the bearing stands I need to make the bearings to go into them. The casting set came complete with a round stick of bronze - not the easiest to make split bearings out of :disappointed: So I have cut in half then soft soldered the of bits of brass together to form a block. This block was nearly square by adding a couple of slithers of aluminium I could make the block square which means I could hold it in a self centring four jaw chuck:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5191.JPG)
This allowed me to turn it to 19mm diameter:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5192.JPG)
Which could subsequently be held in a collet:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5193.JPG)
To make a perfectly round bar with the split dead on the centre line::
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5194.JPG)
You can see the supplied piece of bronze next to my split brass bar. One last thing before starting the boring and turning activities I need some plug gauges:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5195.JPG)
There are three of them: one for each of the centres of the bearings and the third is for the outside of the bearings where it goes into the blocks ;)
Ready to go so back to watching the pageantry on its way to Winsor Castle :)
Jo
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Nice to see this again Jo, I have haave been quietly looking and wondered if all is well. Good to see that it is. Terry
-
Welcome back Terry :)
The block for the bearings can be held in a collet and bored the smaller 12.7mm diameter and the bore checked using the plug gauge:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5196.JPG)
Then half way can be bored for the wider diameter:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5197.JPG)
With the plugs in place as support the outside can be turned to diameter:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5199.JPG)
One bearing can be turned on each end of the bar:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5200.JPG)
And having parted them off and faced each if you find that the bore needs correcting then you can still do that in the collet :)
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5201.JPG)
A quick heat with the gas torch and they are apart and the fit can be checked on the crankshaft:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5202.JPG)
Onward :wine1:
Jo
-
That was a Cheeky way of 'making them long enough' .... I would have worried that I also had 'glued the gauge' together with the bushings ....
Great to see progress again Jo :cheers:
Per
-
Thank you Per :)
To finish off for today I did a bit more boring:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5204.JPG)
As I got close it was not good enough to measure with a Vernier so out came the telescoping gauges and the micrometre:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5206.JPG)
And finally the plug gauge fits
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5205.JPG)
Having checked the fit of the bearings both in the stands and around the crankshaft it can go together:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5209.JPG)
The gap on the base is not wide enough for the bearing stand :Doh:
Enough for today, other things are calling me :mischief: How did I ever get enough time to go to work :headscratch:
Jo
-
Thanks for the lessons in fabricating split bearings...I'd not seen that before. :popcorn:
-
So many little unique features :) :) :wine1:
-
now I see my mistake.
The upper part of the bearing has so much oversize that the cast attachment for the oil cup still comes out.
A nice job.
Michael
-
Thanks Guys :)
The crank comes as a casting:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5211.JPG)
The first thing is to mount it up in a three jaw and get it mounted parallel - remembering that the circular bosses are actually tapered so we need to check against something parallel:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5213.JPG)
Then we can face the central boss:
(http://listerengine.com/coppermine/albums/userpics/10007/IMG_5214.JPG)
And as expected the little dimple in the centre of the boss was not central :ShakeHead: We need to drill deep to make sure our subsequent drilling follows the centre and not that dimple:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5215.JPG)
Having drilled and reamed it to size it can now be mounted on the hole on an expanding mandrel and the bottom faces both machined flat:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5216.JPG)
Now we can take the mounting mandrel and casting over to the milling machine, having clamped it square, find the centre of the hole with an edge finder:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5217.JPG)
Then use a pointer to move up to the correct throw distance then tap the casting to centre it on the little end:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5218.JPG)
Now it can be drilled and reamed:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5219.JPG)
We have the holes:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5220.JPG)
Now we can take the two bosses to distance:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5221.JPG)
You can see the hole drilled from the rear came out in the centre of the big end boss from this shot while the crank was rotating on the mandrel:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5222.JPG)
Mounted onto the crankshaft we find:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5223.JPG)
It hits the side of the hole in the bottom casting :wallbang:
Jo
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Jo - I think you will find it goes the other way round.
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Indeed as the conrod will otherwise hit the crankshaft end as it is in the photo
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(http://lister-engine.com/coppermine/albums/userpics/10007/Original_etching_1b.JPG)
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Nice and very instructional post as usual Jo :ThumbsUp:
And the little 180 wrong placement is another thing most off us can relate to (one way or another) :-X
Per
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Oh good someone is actually watching the build :LittleDevil:
Jo
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It will be interesting to see where the crank pin falls when it is the right way round, looking at the drawings even if fitted as in your photo it should have had 3/32" clearance.
Though the way the ctr line of the pedestal is dimensioned off the side of the cutout is not a good way to do it. Would have been better dimensioned from the engine ctr line or at least how far offset from the column ctrs
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Hi "JO" , just catching up with this build ....looking good and some of those castings look really lovely and well detailed . An interesting engine and will be interesting to seeing it in motion...
"W" :ThumbsUp: :popcorn:
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Good to see progress Jo!
Dave
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Having had a joyful holiday from the workshop it is time to make some swarf again :whoohoo: :
The flywheel was turned on Big C by first holding it on the outside of the jaws of the chuck:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5233.JPG)
Not forgetting to turn the back surface:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5228.JPG)
Before using coordinated turning to shape the curved outside surface and boring the centre so everything runs true :)
To enable me to trim up the inside edge of the flywheel I chose to mount it on a face plate:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5234.JPG)
Flywheel in place:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5235.JPG)
And then it was time to take it all apart again:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5236.JPG)
So I could start looking at the yoke:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5237.JPG)
And yes another wrong measurement :ShakeHead: the space between the two outside holes needs to be the same as the two slots in the engines table.
To start this piece I have drilled the three holes into the piece of steel I intend on using to make this part:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5238.JPG)
I will then find a piece of scrapbinium and use these holes to secure the yoke to the scrapbinium jig while I machining it
Jo
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:whoohoo:
Coming along rather nicely .... :ThumbsUp:
When are we likely to get a 'chuff-chuff' out of it ?? ( or prefer not to say ;D )
dave
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Wow, seeing it together on the bench with the flywheel shows how big it all is! Impressive. :popcorn: :popcorn: :popcorn:
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Thanks guys. Yes it is another rather large model engine :facepalm: I keep thinking I will need to buy a bigger house to provide somewhere to store the engine collection but the idea of having to move a workshop (again) :paranoia:
The yoke has been mounted on the jig:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5239.JPG)
So I can do a bit of Lawnmower milling. Start at one end with the cutter above the work and beyond the outside of the bar, move in a little bit at the correctly calculated distance from the centre, drop the cutter to provide a curved milled slot. Back to half depth and mill to the other end of the scallop, drop the cutter to the bottom of the material and mill back to the starting point. The scallop is correct when (for a 6.35mm cutter) the two ends of the milling cutter path is 4.7mm out from the centre line of the work and 23.7mm/6.35mm respectively. The last cut was only 0.1mm deep full height and I went up and down a couple of times to help get a smooth finish.
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5240.JPG)
Finally:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5241.JPG)
I have just knocked up a couple of holding buttons to match the holes in the bosses when I was encouraged by a family of long tailed tits to top up what Dave would call the "Dickie tweet grub station" and I have just noticed it is also getting dark. ::)
To be continued :noidea:
Jo
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Good to see you back at the swarf making again Jo, just did similar at the weekend for my much modified James Coombes II.
(https://hosting.photobucket.com/images/v156/jasonballamy/20221125_182132.jpg)
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Happy to see you back making :) :) That's quite a machine :praise2: :wine1:
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Great progress and nice Family shot earlier (I agree - it is big) - so good to see you back Jo :cheers:
Per
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looking really good Jo and yes our extended summer has kept a lot of us in the garden ?!!
Willy
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Thanks Guys :)
Willy I hope you are not getting confused where Jason has felt the need to show his off in a "Blue Peter moment" rather than waiting for me to finish the one I am machining for my engine. I will of course in this build thread be explaining each step needed to machine one so the forum members can make their own ;) .
It is looking like workshop weather :cartwheel:
Jo
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The bosses on the yoke can be done using a rotary table:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5243.JPG)
Other alternative means to round the bosses is to use filing buttons, not forgetting a bit of cheating using the band sander ::)
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5244.JPG)
Giving all three bosses round but we still have a bit more to take off:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5245.JPG)
We need to put the angles in place and to do this I am going to use the lathe. With the yoke mounted on a jig the top slide can be spun round to provide the correct angle:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5246.JPG)
Then, with a rounded tipped tool, the taper can be turned:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5247.JPG)
A quick clean up with some emery:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5248.JPG)
If you recall the ends of the two side rods still need to be taken to length. Having cut the centre off of the end I used the turning buttons on the end of the side rods to increase the length of the rod I could hold in a collet to turn the ends:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5250.JPG)
All three rods slid into the yoke:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5251.JPG)
So I can't put it off any more I need to make the straps :disappointed: Actually no I could do some cross stitch instead. :wine1: I must make sure my hands are clean first :stickpoke:
Jo
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That yoke came out great! It looks sort of like a part from a jet or rocket ship.
:popcorn: :popcorn: :popcorn:
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Great stuff Jo.................I'm still using the motorbike excuse to not continue with mine ::) Terry
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Beautiful looking yoke, Jo! :popcorn: :popcorn:
Other alternative means to round the bosses is to use filing buttons, not forgetting a bit of cheating using the band sander ::)
So, why is using a belt sander cheating?
Kim
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Wondering too, is belt sanding a sin in the machine shop? LOL
Forgot to add, nice work, Jo. Quietly following this build...
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Wondering too, is belt sanding a sin in the machine shop? LOL
Forgot to add, nice work, Jo. Quietly following this build...
I just used mine to round off some corners on the latest pieces on my model, so I hope sanders are okay! Not for dimension-critical pieces by any means, but for decorative bits I think its fine.
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I greatly appreciate the how-to's.
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Thanks Guys :)
I always thing using the belt sander is cheating because as an apprentice that is what my instructor told me. He also told me that draw filing was cheating and I should use emery paper :thinking:
The problem with belt sanders is they can remove more than intended but in this case the buttons slow things down so it is easier to "get away with it".
I forgot to mention before: if you have a Dremel or a Foredom the little drum sanders are really handy to get at the bits the belt sander can't reach
Jo
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How was the original Clarkson design held together? did they suggest silver soldering or just pins or something else. Will you go the modern Loctite route?
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The original Model was pinned.
Jo
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Great looking sub-assembly :ThumbsUp:
I must admit that I love to cheat (lazy bugger) - but I do see the point in sometimes using emery paper, lapping, etc. for the final finish (minimal removal) and will use them when it makes sense to do so.
Per :cheers:
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"I used the turning buttons on the end of the side rods to increase the length of the rod I could hold in a collet to turn the ends"
You got me. What's a "turning button"? Bob
P.S. Glad to see you back cutting metal.
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Thanks Guys.
"I used the turning buttons on the end of the side rods to increase the length of the rod I could hold in a collet to turn the ends"
You got me. What's a "turning button"? Bob
Hi Bob, if you look at the bottom right of this photo:
(http://listerengine.com/coppermine/albums/userpics/10007/IMG_5250.JPG)
You can see a "filing button" the same short length of rod with a hole through it, known as a button, can be used over a diameter as a sleeve to increase the diameter of the piece. If you look at the side rod to the left you can see the other button slid over the end. Where the 7.2mm collar on the end of the side rod was only 1.6mm long. By adding the 8mm long button there is sufficient length to grip in the collet and thus hold the side rod to turn the end :)
Jo
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Ok, the button isn’t split to add grip only for alignment. Got it. :)
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To make the bearings for the straps I have a secret piece of soldered together brass:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5263.JPG)
It makes it easy to turn round bearings with a central split line on them:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5265.JPG)
And if you do not turn it just part it off you get square ones.
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5266.JPG)
You may have noticed I have bored the square ones but not the round ones as there is a tendency for them to be pushed apart and it is just as easy to put the round ones in a collet to take a nats whisker off if required and to drill the bore then:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5267.JPG)
The the slot round the outside of the square ones cane be milled:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5268.JPG)
And afterwards taking the smaller of the bearings down to 11.1mm by milling with the cutter turning away from the central slot to avoid any distortion/burrs into the slot.
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5269.JPG)
Once a little heat is applied these fall apart and can be put with their other half.
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5271.JPG)
I should mention the hole in the centre is still slightly undersized and I will ream it once these are fitted into their straps :)
At this point there was a set back as I discovered my beloved Facom 603E hacksaw frame has a crack in it :wallbang: I now have to find an alternative but they all want to supply ones with that horrible "soft feel" plastic on the grips that goes horribly tacky after a couple of years :-\
Jo
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Great job on the bearings! :popcorn: :popcorn:
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That's very cool!! :ThumbsUp: :ThumbsUp: :cheers:
Was it soft solder? Do you use regular round solder, flat pieces of solder, or one of those ground up solder pastes?
Would superglue work for this?
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Thanks Guys,
I use plumbers flux and, having first cleaned the surface, liberally paint the flux on the two surfaces I want to solder together. I then put them face to face and warm it up with the propane torch. Every now and then as it warms up I poke a piece of regular round soft solder at the joint. At some point it will flash into the heated joint, when it melts I just keep feeding it in. The solder will follow the heat along the bars to the end ;) Then you need to choose if you want to let it cool with the joint horizontal or leave it vertical and risk. I normally leave it vertical as the solder pulls the two bits of brass together and it avoids the risk of the two bits sliding out of line but I will press the two bits together as it cools just to make sure they are tight together.
I had no success with super glue as the piece gets rather hot when you machine the bar and it falls apart as you part it off (and the workshop Gnome then takes a fancy to one of the bits and that is the last you see of it :ShakeHead: )
Jo
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Thank you Jo for the detailed method. :popcorn: :cheers:
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Good start to 2023 Jo - very informative :ThumbsUp: :cheers:
Per
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I had no success with super glue
I tried and failed with super glue as well. There may be some "super glues" that would work, but the typical DIY stuff is not up to the task.
Gene
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That's cool how you did the half-round/half-square bearings, Jo! :popcorn: :popcorn:
Kim
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Now for the tricky bit: the straps :paranoia: We are going to do this the opposite way from what seems sensible ;)
Having made two bits of steel the same 15.8mm width (yes one was 16mm ::) ) two holes drilled under diameter near the ends I can round the ends:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5280.JPG)
Two bits of bar with three rounded ends and one where the cutter caught :facepalm2:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5281.JPG)
Time for the slots. Having zeroed on one hole and knowing the distance to the other I can mill between them with a suitable small diameter cutter:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5282.JPG)
Moving to a bigger diameter cutter I need to first open up the two outer ends:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5283.JPG)
The slot was first opened up with an 8mm, then a9mm and finally a single cut under power feed using a lovely new 9.5mm cutter that Dave gave me. THANK YOU Dave 8)
The second needs a second hole drilled in it before I can do the same on it:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5284.JPG)
and the battery on my camera has run out :facepalm: Time for a re-charge and a coffee.
Jo
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::) :) :wine1:
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:popcorn: :popcorn: :popcorn: :cheers:
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I missed this build but have now just read from start to date. Very good write up, loved the detail in the set-ups and methods, all very clear and logical, as always, thanks for that Jo, and very nice workmanship too. Will now watch this one out, so you have another following.
Just out of interest - what replacement hacksaw did you end up with?
Chris
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Hi Chris,
I brought a standard Eclipse frame but I am not impressed as the blade twists as you tighten the wing nut to tension the blade so it won't cut straight >:( I have to get a pair of pliers on it to straighten up the blade to get it to cut straight. I can't see me remembering to do that every time :disappointed:
Jo
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Can't see that hacksaw lasting long as First Choice hacksaw for you Jo, OK as a first reserve maybe, but that sounds really poor, thought Eclipse was better than that
There are a bewildering number of different hacksaws on the markets with as many different prices to match, so knowing what may be a good one is not as easy as it may seem, as you have just found out, and as you point out many seem to have those rubbishy plasticy/rubber handgrips that go all yuckky in a short while. Tricky one, hence the question! :ShakeHead:
Chris
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Have they changed the design? I've had an Eclipse frame for many years, and the pegs on both ends have squares where they pass through the frame, so they can't twist when I tension the blade.
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The square ends are a loose fit :-\
Another thing you shouldn't do is buy milling cutters from Arc Euro and expect them to be the size quoted/ printed on them :Mad:
I just went to do the next bit on these straps which is to position the cotter pin slots. To get some idea of the spacing I put the end of one of the rods into the gap and found it rattled around :o Out with the vernier and the slot was over width, check the cutter and :toilet_claw:
The other Arc cutters are also oversized :censored: Time to start again :'(
Jo
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The old Sandvik 225 was a good frame and what I still use, Bahco do one that is almost identical
https://www.bahco.com/gb_en/professional-hand-hacksaw-frames-with-aluminium-handle-300-mm-pb_225-plus_.html
Monument also do a similar one under their own name and also branded with other names
https://monumenthandtools.co.uk/monument-12in-hacksaw-frame-mon1921d
No sticky grips of loose end locations that can twist and they both have the 45degree option for sawing long strips of deep cuts
They must have sent you specials jo as all mine seem OK. Have you let Ketan or Iain know. Hope that big ears and the elves has not been putting them in the wrong boxes. 4-flute is not ideal for slots anyway.
EDIT just saw the photos and its the cheap ones you have, better to stick with the premium, no wonder you were given them, what is it they say about beggers?
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They must have sent you specials jo as all mine seem OK. Have you let Ketan or Iain know. Hope that big ears and the elves has not been putting them in the wrong boxes. 4-flute is not ideal for slots anyway.
EDIT just saw the photos and its the cheap ones you have, better to stick with the premium, no wonder you were given them, what is it they say about beggers?
I just put it down to poor Chinese quality control again. I have labelled them all Arc Euro cheap and oversized.
If you have been following along you would have known I used then to skim off the last 0.25mm, or rather it should have been. I'll go back to milling down each side to get them to width.
Jo
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I only have a 7mm one of those and bought it for counterbores so have not used them for "milling" beware the ball nose ones as are based on rugby balls or possibly aimed at the american market :-\
That's what I tend to do particularly if the mating part has already been made, plunge the ends to size and then use a size down cutter and offset for each side and adjust to a good fit, takes a bit longer but not as long as remaking loose parts.
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Having recognised that Chinese quality control continues to be an issue onward with converting perfectly good bits of metal into swarf...
A replacement piece has been made for the pair of side rod straps. This time before removing it from the vice I checked the slot:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5288.JPG)
As you can see it is nice and tight but having removed it from the milling vice it opened up again :rant: this time I use a specialist tool (vice) to make a width adjustment :-X And checked the width again:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5289.JPG)
On the second on I left it a smidgen (technical measurement ::) ) smaller and it was a nice fit:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5290.JPG)
Now to work out how far down to cut the cotter slots :thinking: Then we can set about showing the joys of cutting them :facepalm:
Jo
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Looking very good Jo. :NotWorthy:
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Flattery will get you everywhere :lolb:
Another Drawing feature :facepalm: Cotter slot position and the length of the side rods straps :ShakeHead:
Looking at the big end drawing you can see there is a line I have ringed in green I will assume this is the front of the slot cut in the strap. Yes it is in front of the rear of the bearing but it is not doing any work (just looking tacky :-X) )
At the bottom I have arrowed the line that seems to be representing the back of the bearing, the front of the cotter and the end of the rod :headscratch: We need the cotter and pin to pull the rod and strap together around the bearing so we need the slot to move along rod so that it is actually in the end of the rod not a slit in the end :facepalm2: Ideally with 3mm but it is likely to need to be shorter.
Length of cotter slot: this has to be the width of the narrower of the top or bottom of the cotter. Once through one side of the strap, the rod and the other side of the strap it slides sideways and leaves a gap for the pin. :thinking: The key surfaces are the outside (furthest from the bearing) on the straps and inside (nearest the bearing on the rods. 5mm slot with a 4.76mm cotter top would work.
Lets not be hasty and I will think further on this. Might be best to draw it out ;)
Jo
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this time I use a specialist tool (vice)
I left it a smidgen (technical measurement)
This is getting far too specialized and technical for me. ( ;))
Still following along with interest and pleasure, Jo. :ThumbsUp: :popcorn:
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Following along also. :ThumbsUp: :popcorn: :cheers:
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Hi Jo,
With it cut as drawn, that extra length of the slot gives the wedge more room to travel as bearings wear and are taken up, at least on the full size engines. A common 'feature' on the original engines.
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As Chris says the green line should not be doing anything you want the cotter to be contacting the end of the rod and right side of the slot in the strap and the wedge to be contacting the bearing. Having a gap between wedge and the left side of the strap allows for taking up any wear.
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I still don't understand that drawing. So far as I can see, there is an open slot milled across the end of the rod to accommodate the gib and cotter. This seems to provide an unconstrained system with an unknown spatial relationship between the rod and the other bits. In other words, what is preventing the strap, bearing halves, gib and cotter all falling off the end of the rod?
I think it would work as probably intended if the gib and cotter were moved some distance to the right, so that their slot can pass as a rectangular hole through the end of the rod.
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I still don't understand that drawing. What is preventing the strap, bearing halves, gib and cotter all falling off the end of the rod?
The wedges through the end of the strap go through a slot in the rectangular section on the end of the rod, and the slot keeps things in alignment. The bearings overlap both sides of the strap and the rectangular section on the end of the rod to keep them from slipping out of the opening. Many times on a full size one there is a set screw from the side to keep the wedges located, or a screw along the long axis of the wedges to set tension and hold them in place. Have got better diagrams here someplace (looking)
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It should be as you describe, but have another look at the drawing.
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It should be as you describe, but have another look at the drawing.
Tha line she points at is not a cut through the whole strap, its a reference to the slot in the strap for the wedges.
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The other drawing for the two longer rods shows it correcty
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Thats a good drawing!
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Yup, that's more like it.
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Shame the sketch as it says doesn't match the drawn parts.
The red rectangles show where the clearance needs to go for adjusting the bearings. It only needs to be less than 0.4mm to work.
The strap needs to be longer than drawn: 16mm so that it goes to the full length of the end of the side rods and fits into the bearing.
Jo
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Hello Jo,
Just read through from page 1. Another one joining your flock. :) :popcorn:
Regards, Steve
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I’m finding this particular section quite interesting.
At some point I will have to make the connecting rod for the Brayton Ready-Motor. I have a full length of BDMS bar waiting to be cut. I also have the cast Brass bearing shells on stock along with gauge plate to make the cotters. I’m going with 1/8” so as to match the stock of Gib head keys that I already have.
Looking at the engraving the strap appears to be just a strip of Steel formed into an elongated “ U “ section. Being a lazy engineer I was thinking on the lines of a single hole whose diameter is large enough to pass the cotter heads through and then the Gib key backed against it. The thought of broaching through some 30 mm of Steel is daunting.
:cheers: Graham.
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Graham as our models are unlikely to see the sort of loads that full size do we can cheat a bit.
Firstly you can make both bearing halves round or both square as the engraving does not show if it is half & half shaped like Jo's
(https://www.model-engineer.co.uk/sites/7/images/member_albums/44290/914160.jpg)
Secondly and this is the cunning bit you can mill into the end of the rod which means you just have to mill a little way in from each side and file the ends squuare rather than have a full depth rectangular slot.
(https://www.model-engineer.co.uk/sites/7/images/member_albums/44290/914161.jpg)
(https://www.model-engineer.co.uk/sites/7/images/member_albums/44290/914162.jpg)
I did the big Tidman that way, bent strap on that one too
(https://hosting.photobucket.com/albums/v156/jasonballamy/Engineering/Tidman%20Organ%20Engine/.highres/DSC00568_zpsadmw8n3u.jpg)
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Definitely a most “ cunning plan “ as dear old Baldrick would have said Jason …. :ThumbsUp:
However the simple round hole will not be seen behind the Steel strap is there another reason against this idea apart from alignment issues?
:cheers: Graham.
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It should work, you could always file a slight curve onto the wedge so it sits nicely on the curved edge of the hole
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Having made 12 of these pesky things for the motion on 'Locomotion' the slot in the rod starts 1/16" from the end, so I should think yours needs to be about the same.
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Is the Locomotion 7 1/4" to the Reeves (David Piddington) drawings or 5" to the Atlier (Mark ??? German) drawings.
Jo
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Its the 7 1/4" Reeves/Piddington version, although I do have scanned copies of the Atelier design, and hard copies of the 1928 ish Greenly 7 1/4" drawings. Mostly I work to the Piddington drawings, although it is useful sometimes to be able to cross check with the others. They all have 'issues' The Piddington valve gear design, as drawn, is unworkable, though his boiler, which I think Alec Farmer had a hand in, is the best of the 3. I don't think the 5" version would pull a person, but I'm hoping that mine will.
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To be able to calculate the potential lengths I can get away with for the side rod straps I need to start by finding out the total length of the rods. That means I need to do the crank rod first ;)
First measure from the top of the crankpin to the underside of the table:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5292.JPG)
63.5mm :thinking: Check the drawing the rod needs to be 59.5mm long:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5294.JPG)
That will leave 1.6mm clearance :ThumbsUp:
Hold rod in square collet to take to length:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5293.JPG)
Mill an equal amount off either side to take to 6.35mm wide:
(http://listerengine.com/coppermine/albums/userpics/10007/IMG_5295.JPG)
Check it fits:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5297.JPG)
and looks ok:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5296.JPG)
Decide how long to make this strap :thinking:
Jo
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Looking great! :popcorn: :popcorn: :popcorn:
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Red 'n' Green - is that just to be able to tell Starbord from Port - or ...?
Good progress Jo :ThumbsUp:
Per
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Red 'n' Green - is that just to be able to tell Starbord from Port - or ...?
Good progress Jo :ThumbsUp:
Per
Not that way round, Per. The green starboard light is to the right on our stretch of water. :Lol:
Looking good, Jo
Regards, Steve
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It is absolutely the same way here (at least when I still sailed) - and / but, it never occured to me (when I wrote that) - that one could make the parallel you just did :facepalm: .... but I see what you mean ....
It's just the way I think of the words in English - or should I say Danish .... as we almost always start by saying "Styrbord og Bagbord". You English has adobted Styrbord as Starboard, and they literarely means the same - but Bagbord more or less translates into Backside ....
Sorry for sidetracking your Thread Jo :embarassed:
Per
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Still following with great interest! :ThumbsUp: :popcorn: :popcorn: :cheers:
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Thanks Guys,
Per: The red shows the end of the strap that is over sized. The green is the correct width.
The big end strap drawing is correct: the distance from the centre line to the end of the strap is as shown 19mm. The side rods is still wrong and it looks like I have made my strap material too short :wallbang:
Jo
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Hi Jo,
Sitting in the arvo sun, sipping a beer doing a catch-up while away in the caravan, nice to see that the little grey cells are being challenged! Coming along nicely!
Comments a page or two back about sticky plastic handles….. find yourself some “Goo-Gone” a citric based sticky stuff remover, works a treat! We had a couple of camping torches which had become very sticky & were destined for the bin, gave the Goo -Gone a try & now they a nice to hold again.
Cheers Kerrin
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Another elegant piece :ThumbsUp: :ThumbsUp: The old engine designs were more stylish than modern ones :)
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I am trying a simple bit :paranoia: to see if I can cope with making swarf again.
The steam chest and its cover come as two separate castings which need to be fitted together. So first job is to mill the top and bottom of the steam chest to just remove the casting marks flat as well as some of the part where the cover is to go to provide a datum. This allows me to measure the thickness and gives me an idea of how much spare there is:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5386.JPG)
So knowing I have the option of leaving the other cover at 3.18mm or 4mm thick I have chosen 4mm because I want the extra thickness on the steam chest later. Now I can do the cover. First a skim top and bottom to get rid of the casting marks, then take the top face so that the patterns are 1.5mm deep:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5385.JPG)
I now need to square up the outside of the casting on the patterned area and then mill the top and bottom. Before squaring off the sides
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5387.JPG)
Now we work out how far is left to bring it down to size and where we want to take it from to keep the pattern central on the piece:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5388.JPG)
Castings are always much more interesting than using bar stock because you have to engage the brain before you cut anything :)
With the cover to width and length (it is still over thick ;) ) I can measure where the centre of the valve spindle wants to be and then take the bottom of the steam chest to height:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5389.JPG)
Time to have a think:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5390.JPG)
The cover over hangs the bottom of the chest: this is ok as I still need to mill that step to the correct length and it still needs the bottom milling. It is best to mill the longer sides before the shorter ends as this makes it easier to square up the ends:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5391.JPG)
Thanks to that step in the top face of the casting I am using a parallel to provide a clamping surface so the casting is nice and secure. I am not taking it to width yet:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5392.JPG)
No there is another 0.9mm on either side to come off and I am about to check inside the steam chest for any nasties before milling those off. Not forgetting to have some lunch first ;D
Jo
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Very good to see you are making swarf again.
How will the butt joint be sealed?
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Welcome back to the metal shop!
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With the cover to width and length (it is still over thick ;) ) I can measure where the centre of the valve spindle wants to be and then take the bottom of the steam chest to height:
Good to see you back at it Jo
What height did you decide on as there seems to be an error (difference) between the dimension on the chest and that for the valve?
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How does the cover seal along that step? Or maybe it doesn't? :headscratch: Love the description of centering up the cast pattern, would not have thought that through on the first go.
-
Thanks Guys,
How will the butt joint be sealed?
With great difficulty. I am still thinking about it. The obvious way would be to leave a lip under the top of the steam chest to go under the cover but the steam chest casting is not the right shape to do that. The gap within chest is 8mm tall and the valve is 6.35mm so there is no space for something to be added inside. :-\
I suspect wellseal will be used along the gap :-X
Jo
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Very interesting, Jo! I've never seen a steam chest/cover like that before. Seems like a rather odd design choice!
Kim
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Kim, The original engine is a little different and in fact the correct detail is on the Clarkson General arrangement drawing but missing from the chest and cover drawing (lost lugs from pattern? ), it's the type of detail that is easily added to a barstock engine at the redesign stage.
If you look at the old engraving of the M&A you can see what may be two additional lugs cast onto the top edge of the steam chest cover though they could also just be separate clamping plates.
My sketch shows what the chest casting is likely to have been cast like with a small lip (too narrow to take a stud) along the top edge so that is why the lugs/clamps were used.
Bit of liquid Silicon gasket may also do.
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Great to see you back to making swarf again Jo :cartwheel:
Hope this is an indication that you're doing better :cheers:
Per
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Hi Jo I have just realised that you are back in the workshop :whoohoo: Wonderful news. I suspect most folk have missed you and hoped that you were OK. I shall have to dig out my engine at some stage......but not until you've done some more tricky bits :popcorn: :popcorn: :popcorn: Terry
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Hi Terry,
I have just realised that you are back in the workshop :whoohoo: Wonderful news. I suspect most folk have missed you and hoped that you were OK.
We have been having a few challenges but I hope to get back on to it after the Guildford show. Who was it said something about having plenty of time once you retire :noidea:
Jo
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I still believe in it when it's time for me in 12 years.
Michael
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I still believe in it when it's time for me in 12 years.
Michael
I hoped to retire at forty but it didn't work out :-\
Jo
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Trust me once you retire you'll wonder how you found time to go to work.
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Drawing Feature :facepalm:
The Valve spindle is shown as 4mm off the port face for the steam chest and 4.76mm on the valve. So that won't work :ShakeHead:
Good job I spotted that before I took the "spare" 1.0mm off the bottom of the steam chest :) Decision time go for the 4mm or the 4.76mm :thinking: I'll update this shortly
Edit: I have just marked where 4.76mm up from the bottom face of the steam chest is and it matches the profile for the gland on the chest so I am going to go with 4.76mm for my centre line for the valve spindle :)
Jo
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Unless it's a slot in the valve rather than a hole, so it can float a bit?
Wilf
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That is the error I mentioned in my previous post
It's shown in hidden detail so a hole rather than a slot, there is also no real allowance for the valve to lift though possible the other lower end can lift enough.
Would need to plot it out to see where the vertical line of the lifting arms comes to decide which of the two sizes is the best option. Also making it the 5/32" puts the hole very close to the cavity in the valve.
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That is the error I mentioned in my previous post
Not everyone can remember that long ago :old: and it is nice to have the corrections detailed on the parts in case someone, like Terry, is using this as a crib to help them build their own engine.
I've decided to make another change to the drawings: By increasing the height of the connection into the valve the 8mm height of the valve chest under the cover seems a bit "thin" more importantly it also reduces the amount of metal available to mount the steam inlet on to I am therefore going to increase the depth of the steam chest to 13.5mm, with a 4mm step for the cover and 9.5mm under the cover, placing the valve spindle on its centre line and it providing more space for the steam to pass over the valve.
Having turned up the steam inlet I now realise that the drawings show the distance to the outside face of the Missing governor valve :facepalm: This means the stem needs shortening and I have more bits to make as the governor and its linkages are missing ::)
Can't see this being finished for the Guildford show :Lol:
Jo
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It was only last week I posted, hopefully you are not getting that :old:
https://www.modelenginemaker.com/index.php/topic,10859.msg268731.html#msg268731
I did look into using this type of chest/cover when drawing up my James Coombes so am familiar with its unique features both good and BAD ;)
Agree that inlet pipe is close to the top edge and not much to screw into, I can't think of anything that would stop you lowering it a bit so you don't risk breaking out the top edge of the cast iron
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It was only last week I posted, hopefully you are not getting that :old:
I've been retired for nearly five years :whoohoo: so I must be :old:
Start by milling the bottom of the steam chest so it matches the height on the cylinder:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5399.JPG)
Now I can turn over and skim a bit off the top of the cover before dropping down to look at where that seperate piece goes:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5400.JPG)
Now to carefully take that shoulder back so the cover fits:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5401.JPG)
And I can now check the position of that over long :-[ inlet:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5402.JPG)
Yes I am ok it is going to come through in the solid bit of casting to the top of the cover (perfectly inline with the valve steam to block the steam flow :Doh: ) so I'll take the steam chest thickness down a bit more to the dimensions I said :)
Jo
P.S. Retirement is horrible you wouldn't like it JB :lolb:
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Time for some drilling: I've moved the central pair of holes and added a couple of extras for the clamps. I decided that 12BA was too small so have gone for 10BA. I might make the stud's nuts smaller :thinking:
Time to turn the steam chest round and drill the long way in for the valve rod, the packing gland and some 1.0mm holes for the 12BA :facepalm2: studs.
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5405.JPG)
Have a look at what the packing gland looks like in the hole:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5406.JPG)
Clearly its too long :disappointed: and it needs shorterning. It is time to clean out the inside of the steam chest:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5407.JPG)
I've made that pocket 32mm long and 19mm wide. The measurements are missing from the drawing so hopefully that will provide a couple of extra mm for valve movement but it is rather tight and I would rather not take it out any further.
You can see where the valve rod hole breaks through the inlet's hole:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5408.JPG)
I think there is enough space for the steam to get in as the inlet only has a 4mm hole through it.
Jo
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Some nice progress, Jo! :popcorn: :ThumbsUp:
This engine has quite a few quirks, doesn't it?
Kim
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This engine has quite a few quirks, doesn't it?
I thought that they are called 'Features / Challenges / Opportunities' Kim :LittleDevil:
I believe in you Jo - but I'm curious on how you solve them all :thinking:
Per :cheers:
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Complex shapes coming out well! :popcorn: :popcorn:
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Glad to see you machining again :) :) :wine1: That engine has quite a few features ::)
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The holes for the cover have been drilled:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5409.JPG)
The inlet has to be tapped square.
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5412.JPG)
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5413.JPG)
A pair of clamps have been made:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5414.JPG)
before using JB Weld to secure the inlet:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5415.JPG)
Once fully hardened the four mounting holes can be drilled. The valve spindle needs to be first drilled:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5417.JPG)
Then it can be mounted on the steam chest with some buttons and the whole lot filed to shape:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5418.JPG)
Someone forgot to take a pic of the finished gland. :disappointed:
Jo
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I looked around for some suitable gunmetal for the valve and found these:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5422.JPG)
The big flat bit is the reject slide valve from the Halls rotary and I decided it was ideal to take the valve out of. To make sure I got "value for money out of it" I used a slitting saw to cut it off:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5424.JPG)
Before drilling the end of the valve I made sure I marked it with a pen ::) The slot was easy to mill being 1.6mm in from the end. I had been concerned that the gunmetal would bend away from the cutter (and was ready to use a vice to push it back but it cut true :cartwheel:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5428.JPG)
The nut is a piece of 3.2mm square brass tapped 7BA. The tapping was done while the piece was still in the drill vice to prevent the threading pushing the nut sides out:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5429.JPG)
and putting it together:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5430.JPG)
I have put them off as long as I can I need to make the 10BA steam chest studs and then I need a valve spindle.
Jo
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Nice valve. Watching along...
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Nice valve. Watching along...
Thanks Chris,
Hopefully the pictures are now once again visible on the entire thread since they got dinged because someone (not AdeV) did not pay their annual Domain name fee :stickpoke: I had the joys of replacing all the jpeg addresses in the entire thread :facepalm2: and it should now be fixed. Please give me a shout if I missed any.
Jo
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They look to be all showing!
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Another part made and
a some problems solved :praise2:
Good to see familiar faces here again :cartwheel: :cheers:
Per
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Hi Jo,
Nice to see you making some progress on your engine. Looks good, as always! :ThumbsUp: :popcorn:
Kim
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Nice work as usual Jo. I think I must have a different set of drawings to you.......mine shows no counterbore under the entablature fo r column spigots, neither does it show positions of the four pads you have JB'd on top.
I have made a start on mine checking dims on everthing that's been made. Terry
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There are two sets of drawings for this engine kicking about, a few times throughout the thread when Jo has pointed out errors I have said the other set of drawings would seem to have been corrected as they show different. Though I don't think that is shown on either.
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I think I must have a different set of drawings to you.......mine shows no counterbore under the entablature fo r column spigots, neither does it show positions of the four pads you have JB'd on top.
Those were my additions ::) I felt that the spigots provided better location for the table than relying solely on four threads. The eight pads are on the original etching ;)
Jo
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Proper Job :ThumbsUp:
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Terry made me aware that the steam passages from the ports up to the top of the cylinder are rather long and at 2.3mm diameter very small :paranoia:
The drawings show 4 of these 2.3mm holes, spaced across a 9.5mm port. Taking into account wandering drill syndrome on holes 54mm long that is going to fail .
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5435.JPG)
So lets look at alternatives:
The cylinder wall is 10mm wide where these holes go through. So you could cut and cover as Terry was thinking. Or your could make the holes a larger diameter.
The steam inlet to the chest is 4mm ID = 25mm 12.4mm sq Cross Sectional Area. Four 2.3mm holes provides for 57 16.6 mm sq. :thinking: Two 3.2mm holes spaced 3.5mm out from the centre would provide 40 16.3 mm sq CSA, Two 4 mm holes are 24.4mm sq CSA. And with two drilled holes rather than 4 the cylinder cover stud could be retained.
I am tempted to drill two at the 3.2mm then take them out to 4mm. But not today :hellno:
Jo
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If Terry is using this as a guide I'll make a correction or two.
Inlet area is more like 12.5mm2, it's radius squared, total area of the four 3/32" holes is about 16mm2 not 57mm2 :headscratch:
The holes don't just act as the inlet passages, on the return stroke they act as the exhaust passages so should really have their cross section compared to the smallest area on the path the exhaust will have to go through eg the two 4mm holes of 25mm2 total area that connect to the band around the cylinder
Your two 4mm holes would equal that, I'll leave it to others to consider friction losses :LittleDevil:
Or you could happily get two 5mm holes on 9mm cts that break into each side of the port and leave plenty of metal between for a stud
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Its an age thing :old: After 5 years of retirement the brain does not work as it used to :ShakeHead:
You can tell why I am not making swarf today :paranoia:
Jo
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I was just looking at the drawings and it seems like Mr Clarkson was hoping for a bit of drill wander as with the ports only being milled 3/16" deep and the four 3/32" holes being set in 1/4" from the port face there is no way they would ever connect. Could have been nasty for anyone watching through the port for the end of the drill bit to appear but it would just keep going until it came out the bottom of the cylinder :ShakeHead:
I does need a bit of careful placement of whatever size holes are decided upon and an increase in port depth if the area where the port meets the holes is not to have too small a cross section
This would be two 5mm holes, same 1/4" in from the port face and 4mm either side of ctr line. Port milled 9/32" deep. I'd probably go straight in with the 5mm as it's less likely to wander than a smaller pilot drill. Start with a stub drill then jobber and extra length if needed. If you do go with two 4mm holes to retain a bit more distance to the bore then move them a bit closer to the port face
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Starting with the cylinder mounted correct side top, this means I am drilling the very long holes first. This way round it is easy to hold the casting on the port face and I chose to zero in on the stud hole:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5436.JPG)
I decided to place the two holes 4mm out either side of the stud and 1mm in towards the bore, the cylinder is curving away from the hole and if you recall I have a step under the top cover like the original and I don't want it leaking :paranoia:
Starting with a new stubby drill , then a new standard drill and finally a long series drill complete with its depth gauge (so we don't do a Jason ::) ) the two holes were drilled to depth, making sure to keep clearing the swarf from the hole. If like me you are using a quill feed you can feel when it breaks into the port.
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5438.JPG)
Finally adding a 2.3mm step in as per the drawing to provide the steam feed into the cylinder:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_5440.JPG)
Blowing through the port will clear out any swarf that thinks the port is a nice place to stay. In my case I also had to put the cover on the top of the cylinder and block up the bottom of the cylinder to prove to myself that yes the top cover does seal the cut away area :)
The other end is easier to drill but not as easy to hold because the shape of the casting does not fit in the vice very easy. If you don't fancy using a vice it would probably be easier to use a stud up through the cylinder bore and clamp across the end of the cylinder. This would also allow you to see the swarf coming out of the cylinder port when the drill gets that deep.
One of my holes on the short end was a bit off to one side in the port so I gave it a little tickle with a bit in a dremel to open up where it broke into the port :-X
Jo
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Still following in the background :ThumbsUp: :ThumbsUp: :wine1:
Deep drilling is a fun sport ::)
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Usual quality work Jo, I shall be a happy person when I reach that stage on mine :ThumbsUp: Terry
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Making studs is not what it used to be 1 :ShakeHead:
(http://listerengine.com/coppermine/albums/userpics/10007/IMG_5450.JPG)
I chose to mount the steam chest on 10 10BA studs, the drawing calls for 12BA which struck me as a bit small. It might look better with 12BA nuts but there are already 12BA nuts on the valve gland so these should be a bit bigger.
A point to note: the clamps get in the way when I try to put the lower cover on - the clamps won't turn round far enough to clear the cover. So it is going to be necessary to full remove them each time to take the cover off.
Jo
1. Back before "woke" made it unacceptable to use a bit of engineering stud humour to make the job of turning up these fiddly little bits a little less tiresome ::)
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Coming along great! :popcorn: :popcorn:
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Parts are lookin good Jo :ThumbsUp:
Sorry to hear that Studs don't give you the same satisfaction as they used to :embarassed:
Per :cheers:
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I would have thought the clamps can be left off for testing and only really need to be fitted once it is all painted and assembled rather than having to take them on and off lots of times but they do add a nice touch.
Woke and PC has never stopped you enjoying your studs before ;)
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Thanks guys
Sorry to hear that Studs don't give you the same satisfaction as they used to :embarassed:
I was told it’s an age thing :old: you get to a point that everything goes south and all you can look forward to is warm knees :facepalm:
Jo
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I just noticed this thread, great looking engine and a great build! Your treatment of the columns improves it immensely.
With so many projects on the list, I probably shouldn't be thinking this way ...... but there is no mention of the castings on Blackgates site. Any knowledge on whether they still sell them?
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It's in their Clarkson Catalogue
Quite like the look of that A frame engine anyone ever seen a complete one and got a photo?
http://www.blackgates.co.uk/Clarksons_Catalogue.pdf
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Quite like the look of that A frame engine anyone ever seen a complete one and got a photo?
Eric has a set ::)
Jo
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You and big ears must be loosing your touch if you have not procured them for yourselves yet. :stickpoke:
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It's in their Clarkson Catalogue
Quite like the look of that A frame engine anyone ever seen a complete one and got a photo?
http://www.blackgates.co.uk/Clarksons_Catalogue.pdf
Hi Jason, Not a model but may give you food for thought https://prestonservices.co.uk/item/thomas-t-crook-true-vertical-engine/ (https://prestonservices.co.uk/item/thomas-t-crook-true-vertical-engine/)
michaelr
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I've finished the valve spindle. Point to note is that it does not provide any adjustment: that will have to be provided by the rockers arm position. The 10.3mm threaded end is a bit short if it is to include two 7BA full nuts and washers. And there is less valve clearance on either end than the throw of the eccentric :noidea: Something for later.
So on to the Valve links. These are long and thin with lots of opportunities for exciting things to happen :paranoia:
(http://listerengine.com/coppermine/albums/userpics/10007/IMG_5462.JPG)
I will be making these out of 5mm square bar with extra material on either end to allow for centres and some machining that will need doing after. First to drill the holes:
(http://listerengine.com/coppermine/albums/userpics/10007/IMG_5455.JPG)
Because the material is so thin I cannot use a wobbler to set up the measurements. Instead I have used my 5mm wobbler to find the back vice jaw and zeroed on the wobbler centre. Before mounting the piece of bar level with the top of the vice jaws and then measuring off somewhere near the end of the bar (remember there is spare on there ) the 7.5mm to the first hole and the 71mm to the next. Drilled with a nice new drill so the hole is the right size.
Time to mark off the centre between the two holes and the end of the tapered part. Noting that one end of the drawing is not drawn right as the slot needs to extend further up the rod:
(http://listerengine.com/coppermine/albums/userpics/10007/IMG_5456.JPG)
Starting in the centre of the tapered section: Turn the centre 4mm round for 10mm either side of the centre:
(http://listerengine.com/coppermine/albums/userpics/10007/IMG_5457.JPG)
I know it does not look like it is in the centre of the rod but it is:
(http://listerengine.com/coppermine/albums/userpics/10007/IMG_5458.JPG)
;)
Now to start the barrel turning. The smallest diameter is 2.35mm so the rod is in danger of becoming our "flexible friend" if we don't keep it under control so all of this turning will be done up near the lathe nose with tailstock support in the centre drill (Did I mention those?) . I will be turning the taper using the top slide. To get it to the correct taper I first wind the top slide to the far left, loosen the clamp and move the top slide a bit and touch the tool against something parallel and wind the top slide back the distance I want to cut the taper at this angle. Measure the gap between the tool and the parallel work piece and initially I want it to be 0.4mm. This will take off 0.8mm from the 4mm diameter.
(http://listerengine.com/coppermine/albums/userpics/10007/IMG_5459.JPG)
Having marked up the centre I can now start blending in this taper with the bit already turned:
(http://listerengine.com/coppermine/albums/userpics/10007/IMG_5460.JPG)
Yes I am cheating and using a 3mm diameter parting off tool to do this turning as it will give me the required shape below the ends of the rod:
(http://listerengine.com/coppermine/albums/userpics/10007/IMG_5461.JPG)
Can you see the line just showing in front of the collet? That is going to be the start of the thinnest part of the taper and as I have the saddle locked the tapers on both rods will be identical :)
Lunch over I better go and do the rest.
Jo
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Good to see you back at it.
Do those taper dimensions need looking at or are you doing the taper in two cuts? 0.8mm off dia sounds like you will end up with 1/8 ", 2 x 0.8mm would give the 3/32" shown on drawing.
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Do those taper dimensions need looking at or are you doing the taper in two cuts? 0.8mm off dia sounds like you will end up with 1/8 ", 2 x 0.8mm would give the 3/32" shown on drawing.
I have used three different tapers to give a nice barrel shape. You can see I used a green pen to mark the end of the second taper before doing on the top rod the third which ends on the line I scribed earlier:
(http://listerengine.com/coppermine/albums/userpics/10007/IMG_5463.JPG)
The thin bit is only 2.5mm diameter.
Lets be honest: The finish on those is still horrible so time to polish it with some emery. A word of warning here: NEVER WRAP EMERY ROUND YOUR FINGERS NEAR MACHINERY. I know it is tempting to hold either end and pull it too and fro but the lathe has more speed and strength than you. I use a flat wooden stick behind the emery and let the lathe do the round and round bit ;)
(http://listerengine.com/coppermine/albums/userpics/10007/IMG_5464.JPG)
I have some delicate machining to do next so I am not going to push my luck I am going to leave it there for today and do some very important stitching :wine1:
Jo
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I had to do a number of slender fishbellied rods, up to 8" long for Locomotion. Rough b---r that I am, I turned the centre section to size, maybe an nch long, then the ends, maybe 1/4" long, complete with finishing radius. Then I simply changed to highest speed and attacked the rod with a series of increasingly fine files until I got the required shape, followed by polishing. It didn't take long and saved a lot of heart stopping moments turning long slender workpieces.
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Nice taper work Jo! Thats some small work, well worth taking a break between steps (learned that lesson the hard way. A few times.)
:popcorn: :popcorn:
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Nice shape Jo :ThumbsUp:
Good to see you back in the Shop :cheers:
Per
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Those cleaned up nicely, Jo.
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As always well thought out and very nice work throughout this whole build thread Jo. :cheers: Having to catch any drawing errors before making scrap parts and then having to do it all a second time isn't always easy.
And I'm certainly not trying to throw your thread OT. But I've run across a method in a few of my old M.E. magazines that mentions using the lathes tail stock and off setting it 1/2 the amount of reduction between the larger middle of the rod and it's small end to machine each taper into that large fish belly radius. Accurately center drill each end of all your shafts, turn each rod to a few thou over it's major diameter between the two ends in the 3 jaw and with a tail stock live center. Then offset the tail stock half the included amount of the small end. That forces the rod to be bent in a natural curve. The lathe obviously has to cut a straight line, but once the part is removed from those bending forces it then forms one half of that fish bellied shape. Reverse the part in the chuck and manually bend it over that slight amount and extend the tail stock quill until the live center will again hold it in that slightly bent position.
Has anyone here tried doing it that way? Yes you'd then have to reset the tail stock back to it's original position for accurate parallel turning, but that's easy enough. Because of the amount of grip the chuck would need to rigidly hold that shaft from moving, my thought was to start with over size round stock, added length on each end for chucking purposes, then fully machine that fish bellied shape. Then mill the ends square, rectangular or what ever other shape those ends might be. The cross holes can then be drilled, reamed or bored since the rest is already done. Your method was more than successful, but I thought it worth mentioning another I've so far only read about.
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Yes in the early days I tried that but it is easier to use a boring head in the tailstock to provide the offset. A few pages back I used this technique to turn the tapers on the column using a ball as the bearing/pivot in the boring head.
Jo
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Thanks for the confirmation that it does work Jo. And I just happen to have the correct MT shank to fit my boring head and lathe tail stock :).
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Finally some swarf :)
I have been making studs for the cylinder cover. These are so exciting to do that I got side tracked and thought that tapping and fitting the 12BA screws on the side frames would be more fun :headscratch: I started by using a little drill to check that yes the holes in the cylinder lined up with the holes in the side frames before using the UPT to help me tap the first three screws :paranoia: Very cautiously.
(http://listerengine.com/coppermine/albums/userpics/10007/IMG_5466.JPG)
Then I screwed that side to the side frame and checked the other side and I may have claimed this before but even that lined up ;D I will have to decide if I want to make some 12 BA CSK screws of counter bore to fit these rather nice cheese head ones:
Both sides now has screws in place:
(http://listerengine.com/coppermine/albums/userpics/10007/IMG_5467.JPG)
Back to the cover studs :Doh: all 8 done:
(http://listerengine.com/coppermine/albums/userpics/10007/IMG_5468.JPG)
And that little gap is still visible under the cover but I suspect it would have been adequate to just chamfer the bottom of the cover rather than having a true gap:
(http://listerengine.com/coppermine/albums/userpics/10007/IMG_5469.JPG)
While I am enjoying making these small fiddle studs :hellno: time to do the easy 5BA ones for the bottom of the cylinder and:
(http://listerengine.com/coppermine/albums/userpics/10007/IMG_5470.JPG)
:wallbang: :wallbang: The base of the cylinder is different thicknesses caused by a slippage in the two halves of the pattern. It will need sorting before I can continue the joyful stud making adventure. Maybe the 20 10BA studs for the side frames would be more fun to do :thinking:
Jo
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Glad to see you back making swarf :) :) :wine1:
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Looking great!
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Great to see you back on it, Jo! I've been enjoying your build :popcorn: :popcorn:
Kim
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The error in the casting is annoying.
What can be done?
Make the right side narrower or apply material (but what?) to the left side.
Difficult.
The model will be incredibly beautiful. Good job.
Michael
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Great to see you back in the Shop and making swarf Jo :)
Per :cheers:
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Thanks Guys,
I decided while I was on a roll to avoid starting with sorting out the casting and did the 4 packing gland studs:
(http://listerengine.com/coppermine/albums/userpics/10007/IMG_5475.JPG)
Enthused with getting that behind me it was time to find the arbour that I used previously and to mount the cylinder between centres on the mill:
(http://listerengine.com/coppermine/albums/userpics/10007/IMG_5474.JPG)
Then we can mill round the base of the casting to get it a nice constant depth:
(http://listerengine.com/coppermine/albums/userpics/10007/IMG_5473.JPG)
While I am on a roll do I want to do another 4 studs :thinking:
Jo
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Nice work, glad to see you back at it Jo! :popcorn: :ThumbsUp:
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Still watching your excellent progress Jo :popcorn: :popcorn: :ThumbsUp: Terry