Hi, I`ve designed and 3D printed a "Piston install jig" fo easy installing your pistons with piston rings in to your engine.
The tool is tapered so the top is wider then the bottom. In this way you can easily fit the piston rings, slide it down and drop it in the bore. Tested it and works great.
The "bubbles" on top are for easily recognizing the top of the jig
Here we go, pictures are self explaining:
And an other piece of 3D that I`ve drawed lately, cuz the speaker caps are mostly gone...
The supports are different left and right and are trapezoid shaped so keep that in mind.