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  • brian Rupnow
    replied
    The only other radical departure from the "casting style" is the connecting rod. On the left you can see the original "as cast" connecting rod and rod cap. On the right is the same con rod and cap machined from solid. Now remember, I have shown the "machined" con rod with no radius on any of the sharp corners. If you wanted to, for "aesthetics", you could file in any number of nice radii on the machined rod, but other than for "pretty" they aren't really needed.
    Last edited by brian Rupnow; 09-05-2017, 10:51 AM.

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  • brian Rupnow
    replied
    The base casting for this engine is only 5/8" deep, and as a consequence, both the flywheel and the crankshaft extend below the bottom of the base. This makes it necessary to use a built up sub base with the engine as designed, to give clearance for the crankshaft and flywheel to rotate. I have kept all of the features of the upper surface, but extended the "skirt" another 1/2" so no sub base is required. The original base casting had sloping sides, partly for ease in casting the part and partly for "aesthetics". I have opted to make the sides vertical for ease of machining. This will have no impact on how the engine functions.

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  • aostling
    replied
    Brian,

    One nice thing about going back to steam is that you can run this two-cylinder engine quite slow. That should be possible with an air engine too. If the latter, you could make the cylinders from transparent acrylic, to show the moving parts in motion.

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  • Rich Carlstedt
    replied
    The parts name is called a "Standard"
    When I bought a Stuart Turner kit back in 1972, it had no standard.
    I made mine with a cast iron flanged bushing for the crosshead part.
    I made the legs out of brass strips 1/8" by 1" by X and 1/8 " by 1/2 by X for the "Leg" of the "T"
    Bent the 1/2" leg to the angle and then silver soldered the 1" flat bar to the lower portion with some extra beyond the bend .
    Then clamped the upper portion in the vise and then used a ball mill the same diameter as the bushing diameter.
    Then silver solder it to the bushing and then soft solder to get your fillets and when painted, it looks like a casting

    Rich

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  • David Powell
    replied
    I did that years ago !

    Originally posted by J Tiers View Post
    Silver solder is the plan, I assume.

    Should not be a problem to do that rib etc with silver soldering.
    IF you make the individual pieces from steel ,cast iron , or brass about 1/8 " larger than the finished size, silver solder them together, then machine you can make a good replica of the Stuart part. There is a book by Edgar T Westbury giving machining and assembly instructions for the Stuart !0 engines. Hope this is encouraging David Powell.

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  • J Tiers
    replied
    Silver solder is the plan, I assume.

    Should not be a problem to do that rib etc with silver soldering.

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  • QSIMDO
    replied
    Originally posted by brian Rupnow View Post
    Well, maybe not insurmountable if you are an experienced tig welder with your own tig set-up. Keep in mind though, that the small outside diameter of the round part is only 13/16" in diameter.
    That would be a problem, wouldn't it...3" bore maybe?

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  • Mcgyver
    replied
    you'd do well to make it out cast iron like durabar like the Stuart original. Its good bearing material as the cross head runs in this. For sure the kits have become very expensive so I don't blame you for wanting to whittle one, but if you wanted to maintain the look, I believe Stuart sells (or did) individual castings.
    Last edited by Mcgyver; 09-04-2017, 09:18 PM.

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  • brian Rupnow
    replied
    Originally posted by RB211 View Post
    Hell, I'll 3d print it for you out of PLA for free, just pay postage
    Thank you for the kind offer, but I'll fight my way thru this with a fabricated part. (Generally, that's where the fun is, for me.)

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  • brian Rupnow
    replied
    This is going to get interesting. Although the solid models have been designed in inches, it appears that in some places the numbers used may be direct conversion from metric. Also, the bolts used are 7BA and 8BA, which I am not familiar with. I will be converting the fasteners to Imperial sizes, mostly #5-40 and #4-40.

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  • Cuttings
    replied
    I have a similar problem. I have been working on William Harris steam donkey off and on for quite some time. I machined the steam cylinders out of Durabar round bar stock by boring them undersize then setting them up on the rotary table to mill the outside. That's all done now and the end covers, pistons and rods are all made and the bores are finised. I just finished lining everything up and drilling the mounting holes. That is all looking pretty good thanks to my new DRO on the new mill. It made the job of getting the holes exactly where they should be a lot easier. Now I have to figure out how I am going to cut the steam ports in the cylinders. The problem is they don't go straight through. I have two ideas. First was to mill slots in the cast iron and then make a cover plate out of some nice thin brass material I have to cover the parts of the slots that don't need to be exposed and go between the cylinder and the steam chest. I am not sure how I can make a good tight seal between the cast iron cylinder and the brass. The other method I had in mind was to try and drill or mill the holes through the cast iron cylinders then plug the ends that should not be open with something like JB weld or Marine Tex. I am making the rest of the parts first so I know exactly where the holes or slots need to be. I might have to take some scrap pieces and do some experimenting before tackling the real thing. As anyone who has tried to build one these knows. The drawings in the book leave a bit to be desired as far as accurate dimensions go. This one will be interesting to follow Brian to see how you make out.

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  • RB211
    replied
    Originally posted by brian Rupnow View Post
    ---If I cared to spend the money, I'm sure I could have it 3D printed. However, I would rather fabricate the parts. For me, the important aspect of making something like this is more about making a functional part with the machinery I have in my little shop.--Brian
    Hell, I'll 3d print it for you out of PLA for free, just pay postage

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  • brian Rupnow
    replied
    Originally posted by awemawson View Post
    3D print the GrabCAD parts with a suitable filament and get then cast as 'lost filament' bronze or iron castings. Some PLA filament is suitable
    ---If I cared to spend the money, I'm sure I could have it 3D printed. However, I would rather fabricate the parts. For me, the important aspect of making something like this is more about making a functional part with the machinery I have in my little shop.--Brian

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  • Baz
    replied
    It is the Stuart Double 10, basically two 10Vs on a common base casting.
    I thought everyone knew these basic Stuart models, they have been so all pervasive for half a century.

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  • sid pileski
    replied
    That's a Stewart model. 10 double v I think.
    My first casting based steam was the Stewart single 10V.
    Some of pu U.K. Folks should recognize it

    Very good castings at the time.
    Should be relatively straightforward to duplicate

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