Instrument Rotator for newtonian

[RyanParle]

Does anyone know if there is an instrument rotator available that will work on a Newtonian telescope?

from what I can see most of them are pretty bulky and consume 2-3" of backfocus, which will probably be way too much for use on a Newtonian.

Also it will need to have enough aperture to take a 2" eyepiece sized fitting on the instrument side to accept a Baader MPCC

I've been thinking about the potential for a DIY job, but its not exactly simple & I no longer have access to the lathes, mills & other big engineering equipment that i used to