dynapath 40m z-axis problem

[lynchee]

My boss bought an used chavalier knee milling machine
with dynapath 40 control intended to be used for drilling.
It is 2-3 days that I am looking a strange thing.
Every time I push the cycle start button to start a program,
the quill (z) incrementally adds 0.8 mm in - direction.
This only fisically while the control shows the same position(i.e z0).
Also the z+ soft travel limit moves down so that, if I jog it back,
I get an "z+ travel limit reached" alarm, before the quill
is completely retracted. if I reference the z axis again
it can fully retract but then each time I push the cycle start
it does the same.
some of you can help me?
do I made anything wrong?

[HillBilly]

You need to go to the setup screen and set the display to show following error, TM5 I believe. then you will know if the control is seeing this as following error.

Darek

[MetLHead]

Sounds like either a feedback problem, or something is mechanically loose.

1) Check the motor pulley, belts etc. make sure everything is tight. Check for loose setscrews. Make sure the coupling between the motor and encoder is tight and not slipping. Check for any loose wire connections.

2) If you did not find anything wrong so far, check if you see the same behaviour when jogging manually. Set up an indicator on the quill and Go to Jog Mode and select 2 (fast) and jog the quill up and down several times. See if the quill will return to a known location after jogging. If not, you probably have a bad encoder.

Regards,
Scott

[Gitanes]

Hello Lynchee
Could It be that in your set-up mode you are offsetting the Z axis, if so, reset to 0 offset.
Gitanes

[lynchee]

hi all,
the problem has been fixed!
METLHEAD you was right. the belt was loosen and the encoder's screw wasn't well tighten too. Now is working fine.
thanks a lot to all who replyed
great forum
lynchee

[MetLHead]

You're welcome! Glad you got it fixed.

Scott