Shakes cutting circles

[seana]

I have been trying to troubleshoot the “shakes” while cutting circles.
You can see the z car shake just doing air cuts.
The “shakes” could be resonance but they aren’t happening in the 4 quadrants as I would suspect. Not the typical chatter marks that have been discussed before.
The worst “shakes” happen around the 7 O-clock area.
I have changed the feeds and speeds.
I have changed the computer.
I have manually changed the drivers.
I have checked the wires (OHM) test to look for bad connections.
I have assigned different channels in the software, may have been a bit better.
I have changed and stiffened the table, “y” car, welding adding bracing bit by bit.
The “shakes” happen anywhere on the table.
With the motors disengaged everything glides extremely smooth in all directions with no binding no effort.
Pinion gears changed a couple of months ago (18 tooth to 20 tooth).

Here is my next thought of what to try to figure out if it is resonance (mechanical) or software (control board/software).
I was thinking of changing the “Y” pinion gear back to the 18 tooth (and change the step value to match) and leaving the “X’s” with the 20 tooth.
My thinking is that the motors won’t be moving at the same speeds in the same spot.
So if the “shakes” happen in another place I could surmise that it is mechanical.

I can’t think of anything that doing this would hurt but I thought I would but it out there to see if there is something that I’m not thinking of.

Thanks for all of your help in advance.

Sean

[fleinbach]

Have you checked the pinion gear to make sure the set screw did not come loose since they where installed? I believe there are 2 screws on each.

[seana]

Frank,
Yea, i have chcked the set screws, but will check again.
They were tight.
Cutting straight lines cut pretty smooth and quite.
Jogging works fine and is quite also

Sean

[scottcox]

Sean,

Also check the v-rollers on your y and z cars. Make sure there's no play or ability to rock or pivot on any certain roller.

[fleinbach]

I should have added to check mainly the X motors. If one has a loose pinion it will cause shaking when it slips but the other one dosen't.

[paul60]

i had the same problem tried everything to solve the problem endup replacing the computer. that solved the problem