bit advice

[dan_nelson]

I have been using a 1/4" up sprial with a 1-1/8 cutter length, carbide to cut black walnut solid stock. not thrilled with the results. Im cutting at 180 in/minute, 15k, 1/8 pass . after 12 pcs or so bits are starting to scream so I turn it down and they still scream. these are cruved pieces so I never reach 180. I also drill indexing holes with the same bit. question is should I try something different ? Ive had good luck with O flutes for plywood however I dont have the cutter length to make this work. Im open to any suggestions.thanks dan nelson

[steve_g]

Dan

A screaming bit wants to be fed.
http://www.talkshopbot.com/forum/showthread.php?t=15176 (http://www.talkshopbot.com/forum/showthread.php?t=15176)

SG

[Ajcoholic]

I'd drop the rpm to somewhere between 11k and 13k.

I generally run my two flute spirals at 12,000 now or less. When I started I was also running at mid teens and was reluctant to slow down the rpm, but I did after many suggestions here and learned it was much better.

[gene]

Since the bit is not getting up to 180 ipm then slow down the rpm . Like they say 11 to 13 k on a 2 flute cutter . I run 12 k @ 5 ips on 3/4 ply but it is softer than solid stock.