This DIY Solenoid V8 Engine Can Produce 1000 RPMs

Traditionally, DC motors create force with a clever arrangement of spinning and fixed parts. Combustion engines, however, turn linear force applied to pistons — via a series of small, controlled explosions — into rotary motion. Of course there are a wide array of variations on either type, but in the video below, Emiel AKA The Practical Engineer, outlines how he made an eight-cylinder DC motor.

The concept works in the same manner as a combustion engine, in that force is applied to pistons that turn a central shaft via connecting rods. Instead of gasoline, however, Emiel’s engine uses electromagnetic pistons, actuated by coils that he wound with a hand drill. This isn’t Emiel's first try at such a concept, as he’s made a V4 and single-cylinder solenoid engine. The build video below focuses on the mechanical part of the setup, with a variety of parts made out of aluminum and brass. He even used a clever 3D-printed jig to help glue the crankshaft together accurately.

Electronics-wise, he’s using two different PCBs. One holds IR sensors to pick up the engine’s rotations, and another is concealed in a wooden stand with MOSFETs to control the solenoids. There was a “bit” of smoke along the way, but once getting it to run, Emiel’s been able to produce a maximum of 1000 RPM with the assembly!

For another take on this type of motor, here's a machined boxer engine that's (also) a work of art!