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Looks like a good start on the chests and covers for the shovel Chris. Don't forget to order your 45 gallon drum of Brasso!
The Stanley stuff out to be split off into a separate post. Until then here is an idea, why not just spilt the cylinders laterally (see attached)? These 3D printings were some 1/4 scale proof of concept(s) that I did a few years back. Yes, everyone has an idea of doing a scale Stanley engine! The idea was the upper and lower half would be furnace brazed together. Perhaps with a little weight on the assembly in the furnace to get a tight (and the strongest) joint. It would require some potentially onerous lapping of the valve seat face after the fact, but on the positive side would make machining the steam passages easier. At that time, I created four registration pins in the corners of the valve chest, which you can see in the parts at the top of the image. But since then I think a better way would be to leave the cylinder bores solid and plant the registration pins (which could be large and further from the center) in that area. They would be drilled away when the cylinders were punched through. Perhaps ball milling a gutter down each side just in from the finished bore so the flux and spelter would have a place to ooze into, and reliving the center so the joint lay tight where the spelter would be. That way the upper half would not float on a entrapped area of flux. Could whip up a screen shot if that is not clear. Models were based on several original engines that passed through the workshop for rebuilds. And yes, the commercial available plans are not 100% correct, but more of a 'stylized' 20hp engine mostly based on the 735/740 series. 1907 20hp cylinder on the left, and a 1913 20hp cylinder on the right (before they had truss rods from the cylinder block to the rear axle.) -Doug
Quote from: gary.a.ayres on March 12, 2019, 06:55:21 AMChris - how big will the Stanley car be?garyI do have a set of plans for a small car, but the main project is a scale engine only. The boiler style for a Stanley is quite different, not that suitable for a model. I am more interested in the engine, not sure yet how big it will be, maybe in the 1:4 scale range.
Chris - how big will the Stanley car be?gary
Quote from: crueby on March 12, 2019, 02:00:35 PMQuote from: gary.a.ayres on March 12, 2019, 06:55:21 AMChris - how big will the Stanley car be?garyI do have a set of plans for a small car, but the main project is a scale engine only. The boiler style for a Stanley is quite different, not that suitable for a model. I am more interested in the engine, not sure yet how big it will be, maybe in the 1:4 scale range.I was kind of hoping you would say you were going to build a full-sized car!
I don't have a foundry but I do have a CNC mill, so my thought was to surface mill the two halves from billet. The inner features are sort of prismatic, so not too much difference between the end results whether one manual or CNC machined them. The steam ports would likely be simplified into an orthogonal s-bend where as with CNC it could be a nice curve closer to the original; but the differences would not be too great. Externally though, it would be a tedious bit of nibbling away to sculpt it on manual machinery. Not impossible, as various model engine build blogs using that approach have shown, but it would consume a lot of time. The commercial drawings I was thinking of were the full size set published by the Stanley Museum in Kingfield, Maine. The valve faces can be cut with a single point tool in a shaper, just. Some sort of lapping to smooth out the planning marks was likely done. They were an incredibly light engine for the time; perhaps a little too light and the rod frame is about as rigid as wet pasta and prone to breaking. Some of the design details were really bad engineering practice. I mean, even things the Victorians already knew not to do! They were constantly evolving as things broke, and seemly changed about every fifth engine. There are innumerable detail variants. Some of these can make modeling easier, or conversely more challenging. -Doug
Hello Chris,I might have ask you this question before, but when you are milling Brass do you over cut or under cut? All you milling looks so clean.Have a great day,Thomas