Dynomotion

Group: DynoMotion Message: 12128 From: easydigisoft Date: 8/19/2015
Subject: Z Axis is dropping slowly down...
Hello.

This is second machine we retrofit.
We have problem with the Z Axis.
When we run program for drilling or other program where there are a lot of Z movements, the Z Axes is slowly going deeper and deeper then it needs. The encoder is ok and shows that everything is ok. I tough it might have some loose parts but I checked everything and all is ok. Everything is tight.

When I zero the Z axis in most down position and when I go up, then go down at zero, the KMotion shows that the Z is at 0 and the encoder is 0 but the head mechanically is about 0.1mm deeper. Then if I repeat this process, the head will be 0,3mm deeper and it goes down. It is not exact value. Sometimes it is 0.15mm, 0.4mm, 0.32mm. I can't find pattern. What could be the problem?

We are using software version 4.33l. I am really confused. X and Y are fine. Z is connected at channel 2.

Please help me I am running out of options.
Group: DynoMotion Message: 12129 From: Tom Kerekes Date: 8/19/2015
Subject: Re: Z Axis is dropping slowly down...
Hi easydigisoft,

That would indicate the encoder is not working or being counted correctly.

I assume this is a differential encoder connected to Kanalog?

If so you might check for a broken wire by scoping or checking with a voltmeter right at the Kanalog J1/J2 Screw terminals.  The signals should always switch from low to high where low is < 0.4V and High is > 2.8V relative to Kanalog GND.  The + and - signals should always be complimentary (if one is high the other is low).  There is a 470Ohm terminating resistor across the + and - inputs so if one is not being driven (broken wire) it will tend to follow the other rather than being complimentary.

HTH
Regards
TK

Group: DynoMotion Message: 12132 From: easydigisoft Date: 8/19/2015
Subject: Re: Z Axis is dropping slowly down...
Yes it is differential encoder connected to Kanalog.
I'll check the voltages tomorrow and report back.
Group: DynoMotion Message: 12133 From: easydigisoft Date: 8/20/2015
Subject: Re: Z Axis is dropping slowly down...
Yep, we fixed it. It was broken wire from the B- signal. Thank you very much.