Edges Burning

[ase3558]

I am doing a project for a client and have been cutting a bunch of 3/4" Baltic Birch ply. Got half way through the first sheet and noticed the edges were starting to burn. I stepped away for a bit and came back and smelled burning. Some sawdust in one of the cuts caught on fire and got sucked down by my vacuum table and put a big hole in it. Thinking the bit got dull and got really hot but it was a brand new bit.
I was using a Rockler brand 1/4" upcut bit going at 12000 rpm and 3 ips and doing .125 depth of cuts...I have no idea what to do. Any help?

[dlcw]

Spindle speed is to fast and feed rate is to slow. I run 10K rpm at 6ips, .5" depth of cut. Have never had any burning on any plywood or composites

[ase3558]

Ok thanks. Ill try that

[ase3558]

going 0.5 depth of cut wont put too much strain on the 1/4" bit?

[ssflyer]

I run that all the time - sometimes full depth on 3/4" material, but it depends on your machine - what model do you have, and do you have a spindle or router?

[ase3558]

PRS 96x48 with a router attached. Would making shallow cuts be buidling up heat because only 1/8 of the bit is being used?

[Ger21]

I don't have a shopbot, but what you're doing shouldn't be generating enough heat to start a fire.

Are you sure the bit is not very dull, or even chipped at the end? Is it spinning the right way?

[ase3558]

It was a brand new bit when I started the cut. Unless that one sheet dulled it half way through.

[Burkhardt]

I agree with Gerry. While you can probably cut faster, this setting is not really slow. I do something similar all the time without problem and the bits last a long time. Something else must be wrong. I would say direction if it was a spindle but with a router that is almost impossible.

[steve_g]

Austin...
Here’s the possibilities as I see them...
1. The bit hit something embedded in the goods... that’s not unheard of especially if it was Chinese goods.
2. The bit was of poor quality. You don’t hear the folks on this forum singing the praises of Rockler bits...
3. I had a third point but old age has caught up with me... Oh well, closely examine the bit and see if it isn’t chipped, broken or horribly dull.
SG