Servo runaway error stops/halts our cnc mill

[bglad]

Hi,
We have a 1994 Lagunmatic VMC-3516 Challenger with Dynapath 20M control.
When doing a rapid move in X axis, we get a servo runaway error and it halts the motion, which requires a complete shutdown and restart.
The maximum rapid speed for this cnc is 650 ipm. When we get the runaway error, the monitor shows the speed to be about 740 ipm.
Is there an easy fix, or adjustment for this ? If anybody can advise us, we will be exstatic
Thank you, Bruce

[underthetire]

Don't know that machine, but I do know Dynapath. My guess would be you have old DC motors in that machine. First thing is check the motors for shorts, blow out the carbon dust, check the brushes. Then get the drive tuned. If it still does it then a tach or encoder is failing.

[bglad]

Thank you for your reply tire guy.
We will do as your instruction.
Bruce, and company