i have a project that i need a very precise power transfer to a ball screw driving a hydraulic cylinder. it has to be very quiet and able to have very high torque. at first i thought i would have to use a planetary gear box, but that would be noisy. but i think a cyclical reducer would be perfect. i can seem to find any kind of site online that sells them or even gives any details and types that are out there. youtube has lots of vids about them though, but i need to find one to buy. needs to be about 4"X4" size.