Run away encoder count on a paired axis
Posted: Sun Jan 12, 2014 8:52 pm
Our GPIO4/MPU11 has been working great since July.
We are now having a problem with Axis 4 which is
paired with Axis 1 to move a gantry in the X axis.
Movement stops as soon as a motion command is given.
On startup homing, in the PID Menu, in the ABS/POS
column, axis 1's count correlates to no movement. Axis 4 on
the other hand runs away even after motion stops. It
even continues when the E-stop is pressed and
released. If the E-stop is kept pressed, it eventually
stops. But it resumes as soon as the E-stop is
released.
The only error message it usually signals is "stopped."
On one occasion I did get an "encoder differential error."
I replaced the Axis 4 motor with a confirmed good spare.
The run-away count resumes with the replacement
and its shaft gently turns. It can be stopped by
by gently grasping it but it resumes spinning when
released.
I also tried pairing axis 1 and axis 5. This yielded
the same results.
Any insight is appreciated.
Richard Rew
We are now having a problem with Axis 4 which is
paired with Axis 1 to move a gantry in the X axis.
Movement stops as soon as a motion command is given.
On startup homing, in the PID Menu, in the ABS/POS
column, axis 1's count correlates to no movement. Axis 4 on
the other hand runs away even after motion stops. It
even continues when the E-stop is pressed and
released. If the E-stop is kept pressed, it eventually
stops. But it resumes as soon as the E-stop is
released.
The only error message it usually signals is "stopped."
On one occasion I did get an "encoder differential error."
I replaced the Axis 4 motor with a confirmed good spare.
The run-away count resumes with the replacement
and its shaft gently turns. It can be stopped by
by gently grasping it but it resumes spinning when
released.
I also tried pairing axis 1 and axis 5. This yielded
the same results.
Any insight is appreciated.
Richard Rew