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Project Notes

#200 Solenoid Motor

A single-cylinder mini-solenoid engine.

The Build

Here’s a quick video of the circuit in action:



Solenoid motors are an interesting curiosity. They are quite impractical, as there are much more efficient mechanisms for converting electrical potential to kinetic energy.

But that doesn’t stop people building some impressive models like this V8 Solenoid Engine.

What I have here is much more modest - a “single cylinder” engine powering an impromptu-wire-art drive train. The mini-solenoid used here has a very small effective stroke - about 8mm - which necessarily constrains the gearing.

I was inspired by 30GB’s similar credit-card mounted model for the layout.

Switching Circuit

The switching circuit is completed by a ~135˚ extra rim on one of the flywheels. It makes contact with a free-standing wire during the “pull” cycle. The flywheels, axle and engine mount are all copper, so the base of the engine mount is grounded to complete the circuit.

The switch controls the power to the whole circuit:

  • 12V battery (at the upper end of the solenoid’s voltage range for max power)
  • mini solendoid with 1N4001 flyback diode
  • an LED indicator with current limiting resistor



The Schematic

The Build

Credits and References

Project Source on GitHub Project Gallery Return to the LEAP Catalog

This page is a web-friendly rendering of my project notes shared in the LEAP GitHub repository.

LEAP is just my personal collection of projects. Two main themes have emerged in recent years, sometimes combined:

  • electronics - usually involving an Arduino or other microprocessor in one way or another. Some are full-blown projects, while many are trivial breadboard experiments, intended to learn and explore something interesting
  • scale modelling - I caught the bug after deciding to build a Harrier during covid to demonstrate an electronic jet engine simulation. Let the fun begin..
To be honest, I haven't quite figured out if these two interests belong in the same GitHub repo or not. But for now - they are all here!

Projects are often inspired by things found wild on the net, or ideas from the many great electronics and scale modelling podcasts and YouTube channels. Feel free to borrow liberally, and if you spot any issues do let me know (or send a PR!). See the individual projects for credits where due.