Fuzz and Tearout with Soft Maple
What's causing machining problems with soft maple? Could be the hook setting, the knife angle, or just too high a moisture content. July 13, 2005
Question
We run a lot of soft maple and at times have a lot of fuzzy grain and some tear out. It seems to vary from board to board. The grain direction seems to affect tear out even with sharp knives and lower feed rates. The fuzzy finish is sporadic and our mc percent ranges from 6.5% up to 10% in the same hack of lumber. Does anyone have any thoughts or suggestions?
Forum Responses
(Solid Wood Machining Forum)
From Dave Rankin, forum technical advisor:
What is the type of tool: carbide or steel? What is the type of head: insert or ground to pattern? I was also wondering what is the hook angle of tool, the grind angle of tool, the type of machine the wood is being run on, the feed rate, the spindle RPM, and finally the amount of chips being taken by the cutter?
From contributor A:
I think the fuzz has mostly to do with the moisture content. The tear out is most likely just a normal mill issues. You can go to a 10-12 degree hook on your heads to reduce tear out, but chances are that will increase your fuzz. We run soft maple without too many issues. I think the dry climate makes just enough difference that we never have any trouble with fuzz. We run about 25 FPM with 20* hook. We have a little tear out, but still an acceptable run.
From contributor J:
Dave, right now I'm using hss ground to pattern. The hook angle is 15 deg and the grind angle is 30 deg. The machine is a bridgwood cm 757. The feed rate is 16 - 65 fpm, and I try to run slow on soft maple probably around 20 fpm. If I go too slow, I get slipping, a jerky feed, and stopping, in which case I increase to keep running. 20 fpm would be a good guess. Tpindle rate is 6000 rpms. The maple origin is unknown. The amount of chips - I joint 1/32 on my first btm cutter, which is the face of my product, and I take another 1/32 with my final finish btm cutter, which are both spiral heads.
