Simple Boxer Engine

thingiverse

Fully printable boxer engine. Use 1.75mm filament as piston pins, friction fit on the piston and loose on connection rods. I've modeled a little lip to the crank pin that can be melted wider so it locks the rods in place. However, don't melt the parts together! In my case, they stayed in place well enough without needing this modification. To widen the lip, heat a flathead screwdriver tip and use it to make the plastic malleable but not melting it, which would fuse the parts together. Put the thumbknob through the center hole in the block and attach the crank after that, as shown in the second picture. The thumbknob should spin freely on the hole in the block. In my case, it was a perfect friction fit after sanding the hole of the crank slightly, but you may need some glue to secure it. Make sure the glue stays between the thumbknobs axle and the hole of the crank. If this project generates interest, I can create a video to demonstrate its assembly. For optimal results, use 0.2mm layer height and 0.4mm nozzle, but I've managed to print with 0.25mm layer height and 0.5mm nozzle with some difficulty in getting the piston pin into place, requiring some sanding on the side of the piston. Print the piston and rod twice for better results. Check out my other projects: One Cylinder Engine (uses the same piston) - https://www.thingiverse.com/thing:3667733, V-Twin Engine (uses the same pistons and rods) - https://www.thingiverse.com/thing:3353257, Radial Engine (uses the same pistons and crank) - https://www.thingiverse.com/thing:3671312