My Altmill MK2’s Y‑right closed‑loop motor just hard‑failed. It’s tripping the E‑stop instantly, and when I tested it on another circuit, it popped that one too. Meter shows 0.00 Ω on both coils, so it’s a dead short inside the motor.
Before I order a replacement, has anyone else had a Y‑axis motor short out like this on the Altmill? Any similar failures or causes you’ve seen?
Thanks for any quick insight.
Have a brand new 2’ x 4’ Altmill running V carve 12.0. The same thing just happened to me. Less than 6 hrs on the machine. Slammed stop no matter what I did. Went through the trouble shooting algorithm. Nothing helped. Scieni has been wonderful diagnosing the problem. Sent me a new Y2 motor. Arrives tomorrow.
Glad to hear they’re working with you. How long did it take for them to resolve your issue?
It’s been a full week for me now with no progress. I haven’t been able to get anyone on the phone, so I dug deeper into the failure myself. There’s a strong possibility that when the closed‑loop stepper motor failed mid‑carve, it caused the Y‑axis to go out of sync. That explains why the machine shifted and cut a hole where it shouldn’t have.
When I hit the E‑stop, the machine shot completely in the opposite direction of home, which now makes sense — the Y‑axis wasn’t synchronized anymore.
Based on my diagnostics, the capacitor inside the motor has failed and is causing a hard short. I can’t wait any longer, so I’m going to attempt to replace the capacitor myself and see if that gets the motor operational again so I can resume my work assignment.
“For anyone else reading this, I went ahead and replaced the capacitor, and the readings stayed exactly the same. That rules the capacitor out completely. The coils still drop to 0.00 Ω, which only happens when the windings inside the motor are shorted turn‑to‑turn. At that point the motor becomes a direct short and can’t be repaired. So the motor itself is definitely faulty.”
Don’t forget that the Altmill motors have the motor drivers incorporated in the same housing as the motor. It is much more likely that the electronics are fried rather than the motor coils being shorted. Unless you completely disconnected the motor coils from the driver before testing, you can not say the coils are shorted.
Having said that, it makes no nevermind because the assembly (motor and drivers) is toast.
Got the replacement motor installed—thank you. I was back in business immediately and finished the project perfectly, just as planned before the failure. “Came back the next day to kick off project #2, but now it’s throwing Alarm 14 and the spindle won’t spin. And yes, I did the troubleshooting exactly as written.”