Prop Balancer

I ordered a balancer without any stand, so I went to my garage and found parts to model around. I used these 9x2mm magnets: https://www.fasttech.com/p/1140103 and made the space for the magnet to be glued into 10mm in diameter and 2mm deep. The nut and bolt was just something random I found in the garage and I don't know like the actual name for them (like M3, M4, M5) but from flat to flat on the nut is 8.65mm and the bolt is 4mm thick, I made the spot for the nut again 10mm and 3mm deep with the hole for the bolt at 4.5mm. I hope I oversized the spots enough for anyone to be able to find random parts around their house. I made it so there are about 53-54mm of floating space and it's 57mm from magnet to magnet (at most open position on screw).

Another thing, I used this prop balancer from HobbyKing https://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=55640 and I don't know if I was sent the wrong one but the ends were flat. I put it on a drill and spun it on a g