On Sun, 14 Jun 2009 15:28:20 -0400, Bob Engelhardt
wrote:

$30, free shipping. 15a, 20 - 80v with TACH feedback (not encoder).
Not for CNC, but good for running a spindle with excellent low speed
torque.

It'll work just fine for most any position or velocity control app,
including CNC. The encoder feedback returns to the controller. The
tach feedback is optional, and generally not necessary with a modern
controller and high line count encoders.

If there's no motion controller in the system and the goal is tight
speed regulation, then the tach feedback is useful.

--
Ned Simmons