Friction Wheel Flyball Governor

Target Driller

New member
I started this fun little Friction Flyball Governor project in the spring and now it fits up perfectly to a Hercules Electric Wizard Model AC generator. The shaft size on the Wizard AC is .374 and the bore size on my governor is machined to .3750"
I used leather strips which I cut to size and turned on the lathe so it spins perfectly true to the shaft.
Functions like a charm against the engine flywheel. … Just thought to share a few pics.


Paul Ellzey

That is a great job you did with the leather wheel. If you would consider doing a few more, I have some in need of repair? Would like to get them going so I can put them on an engine.
Thanks in advance


Beautiful work! I like the friction drive mags. I've probably got 50 or more sitting around. A few are on engines but I'd like to have one on every engine as I think they really add to the finished product. I don't know what process you used to turn the leather on the lathe but when I've done it I have punched the center hole in the leather, then put them on a straight shaft the same size as the hole. I then put a heavy washer (I've used a heavy fender washer) that perfectly fits the shaft and is about 1/8 less than the finished size I want on the leather. I put the shaft in the lathe with the washer against the chuck and then take a piece of steel tubing that just fits over the shaft and extends beyond the end of the shaft about an inch. Put the live center in the end of the tubing and squeeze it up tight. You can easily cut or grind the leather this way and it turns out perfectly centered.

Target Driller

New member
Hey thanks for the nice comments guys!
Tommy is very close to the process I used of fabricating the leather wheel.
I purchased the leather in strips from McMaster-Carr and stacked two layers together for the desired thickness I was after.
I traced (sharpie-fine) a circle for finished wheel outer diameter and punched 4 additional mounting holes to secure to a machined steel flange.
The center hole is 1/2" and was punched out with punch and arbor press for needed leverage. The square leathers were razor blade trimmed close to finish circle diameter as possible.
The leather was inserted onto a 1/2-13 threaded shaft and secured on each side with machined washers and nuts to secure at both ends. I turned the leather on a Hardinge Tool lathe at my work. The leather turns (cuts) very smooth and easily shaped or tapered to any desired angle. The lathe-turned leather wheel is perfectly true to the steel flange center axis.
All steel parts are machined from D2 tool steel for toughness and dowel-pinned to prevent rotation.
The brass balls were drilled and secured to dowel pins (loctite 680) .... I had measured the spring force on another donor Wizard and purchased the same SS spring to match compression force. Prior to final assembly all steel parts was wiped using Birchwood Casey Perma Blue to give it the black oxide finish.
I made a couple of these friction wheel assemblies during the winter months as fun projects. A fun project to help pass some cold winter months.