Hi Karl,I know you are planning a V4 TQ at some point.I was hoping I would be able to mod your designs myself, but Fusion is proving way beyond my learning curve for now. I was hoping to extent the TQ stem down below the body and add an toothed/geared arc that couples with the motor.(I only started 3d printing at christmas when my wife gave me a sidewinder x1.Its going really well for last 5 days, only one bad print so far because the bed was not leveled. I've printed a dozen parts so far.) Anyways,regarding motorised TQ, I came across these a few years ago when I last attempted to build a TQ.They are friction based clutch. I successfully prototyped with a direct drive motor via metal gears with the clutch. I used Pololu Metal Gear motors and a Pololu controller plus these clutches:www.conrad.comMentor 716. Safety Slip Coupling | Conrad.comConrad - your technology specialist. More than 550,000 products for professionals. 95 years of experience in electronics, information technology, mea Just thought you might be interested in them when designing v4 TQ!