These brand-spanking new 12VDC motors are made to move automobile seats but are willing to change. They spin at approx 190 rpm, draw 1.5A no load, and stall at approx 25A. Threaded shaft is at a right angle and is 4-1/8" x 7/16". Shaft thread is non-standard, so treat it as a smooth shaft and mount pulley or gear with a setscrew. Measures 5-5/8" x 2-1/2" x 2-1/2" overall, not counting the shaft, and has power terminals opposite the gearbox with (2) 1/4" mounting holes opposite the shaft. If you're looking for a power supply, we've got one. Just snip the plug of this regulated switching power supply and wire it up. 

Attention robotics boffins: Here's a nice, powerful 12-24VDC Mabuchi brush motor with a gearbox and pulley attached. At its nominal 24DC, it spins 45rpm, draws 280mA no load, and stalls a 750mA. 7.5 in-lbs of torque and is rated for continuous duty. Has a 3/4" long x 5/16" flattened shaft with a 4-5/8" dia x 5/16" wide (3/16" ID) single-sheave pulley attached, with a matching O-ring. The gearbox measures 2-3/4" x 3" x 9-1/16". The motor measures 1-1/16"dia x 1-5/8" long and comes with 7" leads and a 2-pin Molex connector.

Our motorman, CJ, called this reversible 12-24VDC motor strange, mostly because it has the power contacts mounted on the face, bracketing the 11/16" x 1/8" mostly striated shaft, and has no mounting brackets. But that shouldn't stop a clever person like you. (Hint: it was probably made to fit into a sleeve of some sort.) At 12VDC, draws 100mA no load, stalls 850mA and spins approx 900 rpm; at 24VDC, draws 150mA, stalls 2.2A and spins approx 1800 rpm.  Measures 2-1/4" x 1-13/32" dia.

…with this nice little gear motor. Nominally rated for 24VDC and draws .2A with no load, this motor spins clockwise at 24RPM. The motor measures 2” X 1-1/8” and comes on a mounting bracket, but that’s removable. Shaft size is 3/16” dia. by 1/2” long, making the whole shebang measure 4" x 1-3/4" x 2". Rated for intermittent duty. Made in Japan, arigatou.

From Maxon Motor, this nice and efficient gear motor is nominally rated at 36VDC, 152 rpm and draws 130mA, but will run with as little as 3V. At 12VDC, it spins approx 28 rpm, draws 75mA no load and stalls at approx 300mA. Measures 2” long x 15/16” dia with a 5/32” x 1/8” flattened shaft, with (3) 1/16” mounting holes on the face and 1-1/2” leads. Made in Switzerland despite not being chocolate or a watch.