Make Yourself a Third Hand

By Jay Miller
Updated on December 21, 2023
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by Jay Miller

There must be a mathematical formula somewhere that solves the problem of how much effort it takes for an old fat guy to start a 3 to 6-hp engine all by himself! The older one gets, the harder it is to be in two places at once to close the intake valve and use both hands to hold a starter stick or turn a crank.

I doodled around, figuring out a mechanical motion that would reverse the pulling action of a rope into a pushing motion of a shaft to press open an intake valve. Fortunately, there is not a great deal of force required to accomplish this.

I made a mock-up from tongue depressors and old-fashioned round-head paper fasteners bought years ago when we had real office supply stores. After some adjustments, it looked like it would work. A few simple parts were machined, such as pivot bearings, spacers, a shaft, and shaft guides. All were attached to a piece of 3/4-inch plywood.

I wanted the stand to be easily portable and adjustable for different heights of engine intake valves. A 4×4-inch wooden post and some straight 2×4-inch boards did the trick. A pair of 3/8-inch carriage bolts allow the contraption to slide up and down in a slot cut in the plate.

Be sure you allow yourself enough rope (I used parachute cord) to safely reach the Third Hand from the back of the engine. Keep the alignment as straight as possible. And be careful … don’t let the rope get caught in a spinning flywheel!

Rube Goldberg would be proud! If you know who he was, you may really need a starter stick and a Third Hand!

Jay Miller has 40 years of experience writing for hobby magazines in model and prototype railroading and amateur radio. He authored two books on Collins Radio equipment and edited the Santa Fe Modeler magazine for ten years. He is a professional photographer, radio engineer and accomplished machinist. Jay resides on a ranch near Crawford, Texas, and is semi-retired. Contact him at jay@kk5im.com


More Info From the Author

Author Jay Miller will walk you through this project and others on his YouTube channel @RadioTexas.

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