[jeeybee]

We have converted an old Correa A10 to Linux CNC and when we run the Z-axis up and down we get a strange pounding sound that was not there before the conversion.
The Z-axis has some kind of hydralic compensation for the weight which we cant find much info about and maybe that is causing the sound?
It also has a brake or clutch but we have tried to remove that.

Any ideas?

[chevydyl]

You may be moving the z axis too fast. Hydraulic it probably has valving and your causing it to over pressure and possibly relieve through a bypass. That could be the pounding you hear. Try slowing down to see if the noise subsides.

[jeeybee]

Thanks for you answer.
We are on the same track but the sound is there even when we move it slowly, although the frequency increases with the speed.
I think we may have missed something that was regulated by the old controller, how would this kind of hydralic weight compensation be regulated?

[chevydyl]

Maybe there is a solenoid somewhere in the system that blocks fluid flow while powered off. So with the new controller you are forcing fluid through the bypass circuit. Maybe. Get some pictures posted up of lines or anything related to the hydraulics.

[svenakela]

Aah, SWEET! Oh man so many hours I've spent by a C A10 and A16.

Can you record it? Even the crappiest phone video and a youtube upload will help a lot.
If you replaced the drivers with new ones they might have different behaviour causing the motors to shatter etc. It can be the hydraulics too, who knows...

[jeeybee]

We can record it
We did not replace the drivers, we control them with a Mesa 7i77 analog servo card.
What do you mean by shatter?

[chevydyl]

i think he meant chatter.....or shudder could be interpreted the same. post the vid so we can help

[svenakela]

Off coarse Eye meen chatter.

[chevydyl]

Off coarse Eye meen chatter.

funny lol