> >Is there a metal tube through the middle of the washer >=20 > Yes, attached to the frame. >=20 >=20 > >so you don't over compress it when tightening the screw? >=20 > So I don't have to tighten them too tight? :D If there is a metal tube, then it doesn't matter high tight you do the scre= w, it won't over compress the washer and effectively take up all the resili= ence that should be giving the vibration isolation. But I wonder if you could use a softer washer to act as a more effective hi= gh-stop filter (yes I know that is a low pass filter, but the action you wa= nt is high-stop). --=20 Scanned by iCritical. --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .