Scrreeech! PC going bad?

[team08]

My bot is about 1 year old with VERY little use, maybe 100 hours max. Today I cut some ultra light MDF with and onsrud downcut and everything sounded fine. Tonight, I cut some regular MDF with the same bit and immediately it began to screech really badly when I plunged and cut. It managed to cut the part fine but the noise was horrible. The bit had some built up brown gunk and was brand new today. I was running at 4inch/sec at .4" depth (if that helps). It sounds fine when it is not cutting. Any ideas, is it time for a router replacement? Thanks!

[richards]

I get a lot of screeching if I spin the cutter too fast (or have my feed rate too slow). When I have my spindle speed set properly for the cut, it sounds wonderful. Someone said that it almost sounds like paper tearing.

With a router, you may be more limited in your RPM selection.

Also, I get a lot more screeching noise with Freud and CMT cutters than I do with Whiteside and Onsrud. The CMT brand, in particular seems to be really picky with RPM - but it cuts very well - even when I have to hold my hands over my ear protectors.

[harryball]

I found a good set of headphones, preferably with a radio, take care of about 95% of the screeching. If you use ear plugs and headphones your up to 99.5%

:-)


I don't know if the screeching is harmful, but I find it comes and goes as I change RPM's and material. Generally I look at my cutting speed and either slow down or speed up until the noise changes. I mostly notice it in MDF.

Robert