In April of 1941 Popular Science Magazine had an article on how to build an oscillating steam engine. This model is a reproduction of that engine using the part details in the article. I tried to stay true to the parts in almost all aspects. Some things were altered to allow 3D printing.
This model has a reversing lever that redirects the air flow to enable CW and CCW rotation.
While originally designed out of metal for use with steam, this engine runs on compressed air. Please don't try steam. It is a very leaky design.
This engine is running around 1500-1600 RPM.
Build Details:
While the Assembly list calls out 8 mm screws. 6 mm should work in most places, especially the cylinder heads. Item 3 12 mm screw can be shorter.
Spring is 23/64 Dia x 1 3/8 Long
IMPORTANT: Make sure you assemble the lower cylinder cover (12) to the Piston before assembling the piston crank. Attach with Super Glue.
Assemble the Rocker Shaft (20) to the Cylinder(6) with Super Glue.
The mating surfaces of the Cylinder(6), Reverser Plate(19) and Frame(9) need to be smooth.
Parts 4 and 5 have been combined.
Please let me know if you need more details or find any issues.
Enjoy
UPDATE: Added .step file of the assembly - 18 FEB 18
Video of engine in motion
https://www.youtube.com/watch?v=K9ak1Hcorfg
Video of engine in slow motion.
https://www.youtube.com/watch?v=iP8OPRIgomE
Link to Original Article
https://books.google.com/books?id=iycDAAAAMBAJ&lpg=PP1&dq=april+1941+popular+science&pg=PA188&hl=en#v=twopage&q&f=false
http://www.jefferyjensen.com/dw/engineer-mechanical/steamengines - About 1/2 way down the page.
Printer Brand:
Printrbot
Printer:
Infill:
100%
