What I mean by this is a motor with a large hole in the middle, instead of a shaft.
Some motors I found allow to easily remove the shaft, but the bore/shaft diameter I need (at least 4 cm) and RPM (700-900) are not even close.
Where can I find such a motor?
(The motor has to be small. Why it is needed: http://i.imgur.com/eoL79BU.jpg )
A ready DC motor + gears + bearing assemply like this will also work. But I'd prefer not to as teeth will produce more noise and wear off faster.
I'm also skeptical something like this will allow about 900 rpm.
Best Answer
look at modern PMDC washing machine drum motors they often have the all the working out at the rim, and could probably be modified to have a large bore, in a normal machine shop fairly easily. I don't know if spin cycle exceeds 900 RPM or not,
something like this: http://www.fp.fisherpaykel.com/direct-drive-motors/common/pdf/4876_NZ_Motors_BRO_HR.pdf