I was cutting MDF earlier and accidentally set my Depth Per Pass at 1.0 instead of .1, causing the endmill to plunge way too deep and get stuck seconds later. I turned it off immediately but now when running it sounds higher pitched than before. It still cuts and follows paths accurately but sounds of a higher/louder pitch and perhaps a faint grinding sound and I’m concerned something is wrong. It sounds like it may not be reaching the correct RPM.
The collet is fine, I’ve checked connections, belts, and pulleys and they are good. The brushes seem to be worn and I’ve ordered replacements but I’m not sure that is the cause. Is it the motor? Is there anything else I should be checking? I haven’t found anyone speaking on an issue close to this and am hoping someone could help. Thank you in advance for any help on the issue!
Take your bit out and if it is a flat end mill roll it on a flat surface to see if it got bent. Since your buried it and the Shapeoko was trying to move it around it may have bent the bit.
Another possibility is the router bearings may have already been somewhat worn and now worn more. With the router off take hold of your spindle and wiggle it. It should not wiggle. If it does then the lower bearing may be defective.
If everything looks good then make a project cut and see what happens. Noise is subjective and changes with the weather and things moving around our shop.
I have one 4" long bit that cuts 1.5". If I do not seat the bit all the way up inside the router and then pull it back about 1/4" I can hear the bit making a strange noise when the router starts. It is the run out that I am hearing because the bit is not spinning true in the router.