Odd noise

[nat_wheatley]

I tried to create/run a file today to clean the table using the CR command. At one of the corners of the rectangular toolpath, I was getting a loud grinding noise. I believe that at the corner, the spindle moves in both the x and y directions to move the spindle to next/smaller rectangle.

It was setup with a move speed of 8ips, cutter diameter of 4" and 0 overlap between passes.

Anyone know why I'm getting the grinding noise? I'm sure that if I slowed down the move speed it would eliminate it, but I would think that it should be able to move that fast, as there is no resistance.

[Brady Watson]

The 'grinding' noise is most likely motor resonance, which all steppers do at certain speeds. What do your ramps (VR) look like? A screenshot of just your VR values screen would be helpful. (hold down Alt and press printscreen, then paste into a photo program and post it up here)

-B

[nat_wheatley]

When I create/save a screenshot in 'Paint', I can't figure out how to save it in a file that isn't too large to post, but that is large enough to see. I'm saving as a .Ping file...

[gabepari]

Brady, I have had a similar issue with particular sequences of move commands. I sent the file to Frank thinking he would just attribute it to motor resonance. But he ran it through their simulator, I guess just a control box with speakers hooked up to the motor outputs (I'm sure it's not that simple), but the grinding and jumping noise could be heard on the simulator. He was thinking it was a software blip, so my file has been shuffled off to a different department. I haven't heard back in a while, so I'm not sure what it is.

I get them from time to time, pretty rare though. I know it's not static, grounding, electrical noise, or any mechanical problems with my machine because they are completely repeatable on Shopbot's simulator. Hopefully they can track it down.

Gabe

[nat_wheatley]

I'll post the ramp values manually tommorrow

I've changed the size of the saved screenshot so many times that even I can't read it!

[nat_wheatley]

Ramp Values in the order they appear (I'm working in metric):

XY MRS 10.16
Z MRS 10.16
A MRS 10.16
B MRS .4
XY JRS 10.16
Z JRS 10.16
A JRS 10.16
B JRS .4
MRR 5.08
JRR 5.08
3D RT 100
MIN DTC 2.54
SCS 65
FST 5.08
KPST 44.45
KPRR 20.32