On 23 Apr 2007 15:32:39 -0700, woodman"
wrote:

I need to cut many 3 in. and 6 in. holes in 1 inch MDF. I figure on
using a template and cutting on a shaper or router table ( my shaper
goes to 10K rpm) I am not sure what type of bit to use.
It would have to be bearing guided. Any input would be welcome
Thanks
Woodman


The effort is making the template with a perfect round hole in it. I'd
use a circle cutting bit in a drill press using hardboard. If you
want to cut perfectly-spaced holes make at least two same-sized holes
in your template--that way you can use one hole as an index. Use
either clamps or double-sided tape to fasten to the MDF. A
spiral-cutting bit with a bearing would be ideal. A straight-cutting
bit would be my second choice. Use good DC, dust mask. MDF is rough
on cutting tools and lungs.