broken stepper shaft

[barnett]

So I'm printing along fine and on my third print of the day. I come back in to the room to check on it and the z carriage isn't moving. I abort the job, try a G28 and z does not move.

Tried testing the board and wires and the problem seems to be the motor. I was hoping maybe the pulley was slipping. Went to investigate the pulley and the shaft came out.

Any ideas why this would this happen? It did not appear to have crashed anywhere, but I wasn't watching.

I'm guessing the fix here is to buy a new stepper motor. Any suggestions for a good source?

Here's a shot looking in where the shaft goes.

[Eaglezsoar]

One of the best Nema 17 motors I have found for a reasonable price of $15. It has a holding torque of 70 oz in and
is one of the best out there as far as torque. Check out the link:
http://www.ebay.com/itm/3DMakerWorld-NE ... 2a2c00a9db

I have never seen a stepper fail in the manner yours has, but you never stop learning. You could try to epoxy the shaft back in there but I would not trust it. Buy the new one.

Carl

[cambo3d]

that's definitely a manufacture defect, there's no way that a rostock/3d printer could do that..

[Eaglezsoar]

Cambo3D is correct and you should attempt to get a new one from Seemecnc if the purchase was within the last year or so.
They can be reached at support.seemecnc.com

[barnett]

Thanks for this info guys. I'll contact seemecnc today.

If I buy the replacement Nema 17 motor Eaglezsoar suggested, would I have any issues since the other two towers use the motors from seemecnc? Do they all need to be the same motor or any Nema 17 would be fine?

[Eaglezsoar]

You would want to buy a Nema17 motor that has torque ratings the same or more than the other motors.
The motor I pointed out has more torque than the ones from Seemecnc. I would buy the new motor and put it on
the extruder and the old extruder motor would go on the axis you lost, then all the axis motors would be the same.
You may have to adjust the digipot settings in your firmware for the new motor but you should be fine.
If you are concerned then you can purchase another motor from Seemecnc but they are expensive. Is there a reason
that Seemecnc should not be contacted for a possible warranty replacement?

[barnett]

Yes I have emailed support@seemecnc regarding this issue. I'm just trying to understand what to do in case they won't replace it.

Your suggestion about swapping with the extruder makes sense too.

Thanks!

[geneb]

I'm quite sure they'll replace it. It's obviously a metallurgical defect in the shaft.

g.

[tom10122]

They'll replace it, they replaced my 4-axis board a few months ago that skipped steps

[barnett]

You guys are right. Julie sent me a UPS tracking number for it this afternoon... no charge.

[Flateric]

I've only seen this one other time and that was on a nema34 stepper that was brand new. It was also a manufacture defect.

There is no possible way epoxy would ever work in that spot.

Glad the see me guys are on top of things and always doing the right thing though.

The nema34 failure I witnessed was not pretty and not safe. It was mounted up on a very largish knee mill and caused a head crash, broken expensive bit and burned out a driver board on two other axis. The motor maker only covered the motor of course.

[JakeCShake]

So I'm printing along fine and on my third print of the day. I come back in to the room to check on it and the z carriage isn't moving. I abort the job, try a G28 and z does not move.

Tried testing the board and wires and the problem seems to be the motor. I was hoping maybe the pulley was slipping. Went to investigate the pulley and the shaft came out.

Any ideas why this would this happen? It did not appear to have crashed anywhere, but I wasn't watching.

I'm guessing the fix here is to buy a new stepper motor. Any suggestions for a good source?

shaft-1.jpg

shaft-2.jpg

Here's a shot looking in where the shaft goes.

shaft-3.jpg

FYI Barnett.....I was watching that print. It did NOT crash into the bed. Definitely defective stepper...