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Z axis failure

Posted: Wed Aug 18, 2021 11:17 am
by Robert Taylor
I have a 3 axis vertical mill using an M400S control; s/n 60060. In the process of running a cycle, it was moving down into position and at the approximate point of transition from rapid to feed, it stopped. I now get error code 411 on my screen. I have verified that it did not crash into a stop of any kind and nothing I can find indicates the head is tied up at all. I have checked my limit switches and they seem to be working properly too. With power on or off, I can turn the leadscrew by hand freely in either direction. I have checked fuses and tried everything I can think of.
Is there a way to check the servo motor? or what else can I check before calling someone? I have the motor information from the tag, that's all there. Note: the machine was working as expected just prior to this failing. Ideas?

Re: Z axis failure

Posted: Wed Aug 18, 2021 9:24 pm
by cncsnw
K60060 would probably be an M400 (with a SERVO1 drive), and not an M400S (with a SERVO3IO or DC3IO drive).

Do you get "411 ... full power without motion" for any axis you try to jog, or just the Z axis?

Assuming you have a SERVO1 drive (see http://www.cncsnw.com/Drives.htm#SERVO1), when you release Emergency Stop, what is the DC voltage across terminals 10 and 9 at the bottom of the drive? Are the green UV and USV LEDs on the left side of the drive lit?

Re: Z axis failure

Posted: Thu Sep 01, 2022 8:45 am
by rabreu1969
I have a 2 axis Hardinge CHNC using an T39 control; s/n 2188. I'm about to sell it. I started it weekly and always worked perfectly In the process of startup today and pushing home position, Z axis moved to home then X started to move into position, it stopped. It didn' hit the limit switch yet. I get error code 411 on my screen. It didn't hit the limit switch yet. I have verified that it did not crash into a stop of any kind and nothing I can find. I have checked my limit switches and they seem to be working properly too. With power on or off, I couldn't turn the leadscrew by hand freely in either direction. It felt notchy. On the operator side I took off the small CHNC silver cover and used a 3/16 Allen and felt notchy resistance back and forth. Then I could rotate it in either direction but still did not feel smooth. I put my left hand on the body as I was rotating and could feel grinding in the motor body. I have checked fuses and tried everything I can think of.
Is there a way to check the servo motor? I'm assuming the motor went inside. I have the motor information from the tag, that's all there. Note: the machine was working as expected just prior to this failing. Ideas?

Re: Z axis failure

Posted: Thu Sep 01, 2022 8:48 am
by rabreu1969
Part#3879 SN#2044-77
Torque 17 in/lb 2 5 AMPS
WRPM 2350 @ 120VDC
Ferrite Brushed DC Servomotor

Re: Z axis failure

Posted: Thu Sep 01, 2022 1:45 pm
by cncsnw
Take the belt off, then see whether the notchy resistance and grinding are in the motor, or in the ballscrew.