3D printed steam engine

[GordonL]

Have any of you 3D printed a steam engine. This came to mind when I was working on the internal gear for Elmer's Geared Steam Engine and it was suggested that the entire engine could be 3D printed. Is this possible to make a working model of this engine? I would assume that some things like the axle and slide valve and perhaps the piston would be made from steel I would think that the cylinder would be the most difficult to make. I would think that some things would be finished by reaming. Any pointers or cautions? Material/PLA?

[crueby]

I've  printed lots of prototype  parts for engines, mainly to use as guides while machining real ones from metal. Some non structural and  non moving parts too. Plastic parts from pla or petg are not well suited for frames, cylinders,  or any moving parts, too flexible and  wear too quick. Definitely not  for live steam, the heat is too high and the plastic will soften. Any decorative  parts, printed is great.

Printed parts are not dimensionally accurate enough for things like cylinders, and reaming will solve that but wont leave a good enough finish, though you could use a metal liner.


Now, for a hand cranked demonstrator, that could work, with tolerances left loose.

Thats my 2 cents worth, bound to be exceptions!

[gbritnell]

In most of the parts I have printed I find that on assembly they will vary from the model by up to .004. If I really want those parts to fit well I go back into  my CAD model and adjust it. Even then a little filing is generally necessary.  Another thing is which way the part is printed. Changing orientation can sometimes help.

[GordonL]

I may just try it. Perhaps a simpler engine would be better. There are several engines available on the Thingaverse  site so downloading one of those and looking at the parts may give me an idea of how others have done it. I am well aware that any engine 3D printed is not going to perform like a machined engine. Mostly just something else to try.

[Roger B]

Slightly off your topic however Miles has built a selection of working Lego engines using high volume low pressure air from a vacuum cleaner:

https://www.modelenginemaker.com/index.php/topic,11830.0.html

The tolerances don't have to be that good to get something that runs. Runs well is a different subject