Bit heating up too much

[foamcarver]

We are cutting with a 1/8 inch ballnose and a spindle speed of 15000 rpm. I have cut out 11 other shapes, of the same size, but yesterday, The bit kept heating up and melting the foam to the bit. Nothing has changed in the file itself. Anyone have any ideas as to why this is happening?

Thanks
Nikki

[stevem]

The bit is dull.

[foamcarver]

Thanks, I actually just figured it out. I forgot I changed the inches a second from 4.5 to 6 and then I changed it back to 4.5 and have been cutting good for about an hour. I'll have to keep that in mind for the next time it happens

Thanks
Nikki