Working air motor keychain

Downloading, you'll get two STL files (motor body and crankshaft). You need to print these two parts and then snap them together.

If you'd like to add your own text to the engine, please download the simple customizer program (you can purchase just this design or subscribe there to receive many other customizers).
https://www.patreon.com/PrintInPlace_fun

Please watch this short video https://youtu.be/EdCQewq0VxY

This is a highly optimized motor, an engineering masterpiece! :) It's everything at once:
a) very compact (40 x 30 x 20 mm),
b) very powerful (10 mm piston diameter, 12 mm stroke),
c) very technologically advanced: it prints quickly and assembles quickly (no supports, just two parts),
d) quite beautiful. I hope so :) Just look how wonderful the motor looks in silver silk PLA!

Pneumatic motors are a personal topic for me. As a child, I dreamed of making such an engine. And when I got a 3D printer, I was finally able to create such engines. For six years, I've been making these engines increasingly compact and easy to print (see photo).

if you want to legally sell these motor keychains or STL models created by the ASCM3 program, please become an active subscriber of my Patreon page:
https://www.patreon.com/PrintInPlace_fun

3D printing settings:
Print-in-Place, no support
Any PLA (but not fragile).
Most common settings: nozzle 0.4, layer height 0.2 mm, printing speed 50 mm/s
Printing time is 1,0 - 1,5 hours

Further instructions seem complicated. Just print and assemble the motor, and if something goes wrong, check here. 

1. How to assemble motor: 
a) Two parts are printed separately: the motor body and the crankshaft. 
b) After printing the crankshaft, wiggle all the joints to ensure they rotate freely. The more you wiggle them by hand, the freer the joints will rotate. 
c) Insert the crankshaft into the housing bores. Note the L-shape of the middle connecting rod. It should be offset in the same direction as the middle cylinder. 
d) If you're printing large motor (120% or more), you can avoid machining the cylinders and pistons. Just assemble the motor and rotate it, and it will clean itself. 
e) If you're printing small motor (100% scale or less), 3D printing defects may interfere with piston movement. It's recommended to use a 10mm drill bit (for 100% scale) to remove any print defects in all three cylinders. 
f) Feel the cylinder walls of the pistons and the valve core (the middle piston). If there are any defects, use a file or sandpaper to remove them. 
g) Tip: sanding or filing the entire cylindrical surface of the pistons will roughen the surface. This will reduce friction and increase compression. The motor will run 50% better. 

2. How to blow into a motor: 
a) It's better to blow not like this h-h-h-h-h, but like this PPP-h-h-h-h (with a sharp front PPP: this will initially spin the motor). 
b) This "steam engine" scheme has two dead points from which the crankshaft will not start to rotate. Turn the crankshaft by hand and remember any position of the crankshaft from which it starts to rotate well. 
c) The more you pre-rotate it, the more friction decreases and the better it spins. 
d) The motor rotates best when it is upside down. 
e) You can use your hand to help the motor start turning, until the motor is self-cleaned. 

I've printed about 30 of these motors in different plastics, at different scales, and with different print settings. Reliable motor rotation is achieved in all cases (though sometimes it might take 60 seconds of drilling and filing). 

I'm happy to answer any questions you may have.