Simple One Cylinder Engine

Fully printable one cylinder engine. Use 1.75mm filament as a piston pin, it should be friction fit on the piston and lose on the connection rod.

It should work just fine after you have assembled everything, but if the crank keeps coming off the pin, I have modeled a little lip what you can melt to be a little wider so it locks the crank in place. You can do the same thing to lock the rods to the crank pin but I have found out that it's not needed for this version due to the thicker rod.
Ju