A heads up to anyone considering where to buy their NEMA 17 stepper motors.
I made a mistake, probably first of many, and purchased a set of 5 stepper motors from another source not knowing when V1 would have them back in stock. They are rated at 84 oz. in. holding torque so I thought they would be perfect as a substitute. Silly me, I “assumed” all NEMA 17 motors had the same shaft length. Well that is not the case and the ones I received have a 20mm shaft which does not leave enough for the GT2 gear’s grub screws to capture the shaft end without a significant misalignment with the belt pulleys.
I tried flipping the gear but the shoulder height and limitation of the position of the gear on the shaft due to the flat on the motor shaft is such that it results in about 5mm of shim being needed between the motor and the truck mounting surface. Longer M3 screws, increased torque on the shaft and load on the motor bearings etc., etc. Not thinking that is a great option either.
I considered grinding the motor mount thickness down but the raised area is only about 1 mm which would mean I’d have to grind the whole thickness down by another 2-3 mm and I’m not thinking that will work out good in the end.
I can use one of my motors on the Z-axis but the 4 others will need to be exchanged or sold off while I wait to find replacements. There is no spec for shaft length in the V1 description but Googling the item number finds them to be a regular NEMA 17 with a 24mm flange to shaft tip dimension.
Anyone with any better ideas, I’d love to hear from you. Anyone want to buy a higher torque motor for your Z-axis, let me know. 
