Balancer for small-medium airplanes

I wanted to make my own balancer for planes with ruller.
Ruller will allow to measure distance of CoG in mm from leading or trailing edge of wing. No need to mark it on wing bottom and balance plane on fingers.

Size of vertical part of leg is 10x10 mm. So, center (balance point) is 5 mm from front/rear side. Scale on ruller started from 0 (leading edge), you should deduct 5 mm from required distance and this length should be between vertical part of ruller and side of leg. Example: you need