I've perused the threads on how various guys have made prop balancers, but I wanted one like the Du-Bro so I could balance spinners too. So here's my design.



It's a wood framework, a piece of 8-32 all thread, a magnet and a razor blade.

You gotta get the razor blade level with the framework.



I tightened the screw down, then leveled it, then CA'd it in place.

The shaft is the biggest part of the job. I ground a slick spot to ride on the razor blade using my CNC lathe (hand drill and Dremel).



Grind a point on the other end as sharp as you can using aforementioned CNC lathe.



The prop holders are pieces of plastic cutting board. I drilled them then ran the shaft into the holes to make threads, then used my trusty CNC lathe to make them conical.

The accuracy of the system is based on how well you eliminate friction and on how level you get it. I tried props down to 9 inch diameter and it was easily sensitve enough for that. I'll see in the next few months how well it does for spinners.