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Hello everyone,

I have some problems with NEMA17 that come with the kit.
Now I need to replace some of them.
Could you please suggest a compatible NEMA17 for me?

I found A LOT of NEMA17 on ebay but not sure which one will fit my Hadron as motor dimension seems critical.

Thanks a lot !!!!

Help us help you. There is no one "the" kit -- there are several, from different companies, and I'm sure they have changed over time too. So, which kit do you have, and, ideally, what motor are you looking to replace? Almost all have part numbers on them, so give us that, and the name of the manufacturer, if known.

That said, there are only a few sizes of NEMA17 motors. They all have the same footprint, 42 mm square (1.7", thus NEMA17), M3 holes on a 31 mm square, and a 22 mm diameter boss raised 1.6 mm. Most have 5 mm diameter shafts, about 24 mm long (but watch out for more exotic shaft sizes, and for dual-shaft motors -- you don't want one of those). What differs is the length of the body of the motor, with 40 mm and 48 mm being very common. If you get a NEMA17 motor of the same length, same rated current (or close), and the same step size (either 0.9 or 1.8 degree), it should work.

Hi,

Thank you for your reply. I have checked and the p/n is KL17H247-168-4A
I found this item in Automationtech INC store but it is out of stock.
This is the specs.

NEMA 17 BIPOLAR STEPPER MOTOR 62 oz-in, KL17H247-168-4A (5mm single shaft with a flat) 62 Oz In.
Hybrid 1.8° /200 Steps Per Rev.
1.68 Amps Current Per Phase
4-wire Bi-polar
Rated Voltage: 2.8V Resistance:
1.65 Ohms Inductance:2.8 mH
5mm shaft

My old motors are 48mm. body length and as you said the faceplate is very similar to most on Ebay.
I am still not sure about different rated V and amperage which vary between shops.
Do you think flatting the motor shaft necessary? Some says it makes set screw binds better.

I would say a flattened shaft is not necessarily a good thing in the case of the Z axis. Depends entirely on what shaft couplers you're using though. If you have ones with a single set screw, tightening the screw can push the couple off center, inducing a slight wobble.

So, get any 48 mm 1.8 degree-per-step NEMA17 motor with a current rating around 1.7 A. If you're driving two motors from one driver, I recommend that you swap motors around so that you have two identical ones on the Z; if each motor has its own driver, it doesn't matter.

It doesn't have to be exactly 1.7 A. For instance, this one here http://www.alltronics.com/cgi-bin/item/ ... pper-Motor will probably work just fine, although not ideal (not affiliated, but happy customer: bought exactly that motor for my CNC milling machine more than a year ago).

I'm afraid I'm a bit too far away to help at a reasonable price -- I have a Wantai Motor 42BYGHW806, rated 1.7 A, 72 oz in (which would be a better fit), for US$21 plus US$12 postage to the US, but I'm sure you can find something cheaper locally. Anything with a rated current between about 1.4 A and 2 A will work, as long as the holding torque is 60 oz in or better.