I'm very happy with the purchase. Shafts can be made or purchased at ondrive. I swapped the stepper for a dual shaft to allow manual movement and used a modified Mt1 shank 2" 3 jaw chuck. The gearbox is perfect and the 30:1 ration works well. The stepper shaft is 6mm with a 2mm cross pin so it is not a direct swap for normal nema23
these units ( I bough 2) must have been salvaged from very high quality equipment. The motors are very powerful NEMA 17 steppers and there is no backlash between the worm and gear