Cheap high torque servo motor.

I needed some high torque servo motors for a CNC and found some Electrocraft E661 for $27 (including shipping) on eBay. These motors come with a 1000 line encoder mounted on the rear.

Couldn't find exact specs but the closest I found with Google search is from a Electrocraft E660 motor.

Nema 34 size
27.6 oz-in/amp
20.4 volts/1000rpm
26 amps peak
No continuous current rating but assuming around 6amps
550 oz-in peak torque at 20amps

The motor arrived nicely packaged but it does show signs of corrosion on the aluminum surfaces. A bit of clean up, drop of oil on the front bearings and the motor runs fine. Brushes show very little wear.

Tested with a gecko320 servo drive. Runs smoothly from slow to fast. I should be able to get 160oz-in continuous torque at 3000rpm with a 60volt power supply. I plan to use 3:1 GT pulleys to increase the available torque. A good eBay find since a new encoder costs more. As of 5/12/2015 the eBay seller still has some for sale.

[Ripaltico]

Nice vid, what kind of controller are you using? i heard that is hard to mantain the precission when you run it at high rpm.