Summary

Simple propeller balancer for up to 9"

Required:
1 metal screw M3 50mm long - our axle :)
3 screw nuts M3
2 or 4 neodimium magnets (circles 6mm diameter) - 2 on each side depending on magnet magnetic field strength if not enough add more magnets.
4 metal screws M3 25/30mm to mount sides to the base

Simple guide how to:
Cut off screw head and file/lathe both ends to make them sharp (cones).
Put magnets into holes on top of the left and right side element.
Carefully put 1 "Cone" on the axle then block using screw nut to keep it in place (to make it un movable).
Second cone will be movable so you don't need block it with additional nut
Using M3 25/30mm screws attach side elements to the balancer`s base.
Insert propeller on axle and scre it tight.
Put axle with propeller between magnets.

Now you can start performing balancing process.

Enjoy :P