Hey guys,

Does anyone have any experience in dealing with chatter marks on industrial belt sander systems? a bit of a head scratcher this one.....

Hey guys,

Does anyone have any experience in dealing with chatter marks on industrial belt sander systems? a bit of a head scratcher this one.....Only experience is as a customer in the past:
I've been told chatter usually means one of two things

belt is loose and "bouncing" (tension needs adjusting)
something in the material of the workpiece is "grabbing" the sanding medium (moisture? wrong grit? some buildup which leads to smooth spots and rough spots?)

What's the material you're sanding? I've seen 'chatter' in polishing, not to mention 'sanding' (manual and robotic).

We're sanding fiber cement....hard hard stuff......

We're sanding fiber cement....hard hard stuff......Describe your setup.
Are you using a belt sander in a mounted fixed position in a manufacturing setting or are you using a free-standing floor sander?

Is the chatter occasional or a regular occurrence? (Anything you can think of which might be different?)

What quality and grade of sanding medium are you using (possibility of uneven distribution of grit? heavy seam?)

Have you checked the rollers - any debris between roller and sanding belt?

How much pressure do you apply to a cut? (shallow cuts are more prone to chatter)

How level is the fiber cement before you begin? (high spots or dips affect operation)

Ultimate repair - rotary sander to smooth out chatter.

We are using stationary belt sanders set up in series increasing grit. I've mostly figured out why we are getting chatter marks but am now faced with another plaguing question: How do I come up with a spec for it and how do we measure it?

2 factors that could be correlated would be frequency and depth...? any thoughts on instruments for depth for sinusoidal patterns?