[MrForbes]

we were planning on 8:1 chain with a 64:1 or 128:1 BB gearbox, and either the BB motor or the weak Mabuchi motor. Arm weight is similar to yours. We are planning on using a gas spring to take most of the weight of the arm.....and we are also planning on being able to start over and put a window motor or two on it to replace the gas spring and BB stuff if it doesn't work out.