Hello, im building a3wd triangle crab drive platform and are in need for a ball bearing turn table with a hole in the middle ofminimum 10.5 mm. The size of it side * side should not be more than 50 mm * 50mm.

The problem is the smallest I have seen is 3" * 3"

And I have been searching around for a while now ( ebay, google) andcan't find any one of use so I was wondering if someone now where to get one,or how would you make one by yourself, without it falling apart when you liftit.

2 extra question)

First question: How much torque from a motor do you think it takes to turn the wheels when its not moving and lets say the weight is 30 kg, with thin plastic el scooter wheels?

Second question:
is 0.5 second for a 90 degree turn a good reaction speed or should it be faster/slower, for a more smooth drive (I know i'll play around with the turn speed, but if someone know or have experience with it, it will make it easier for me to design a gearratio, now its 30rpm for a 90 degree turn in 0.5 second.