Does anyone make a downcut bit that reverses to an upcutting bit after maybe 1/8" or so?
I’m working on a project where I’d like to use BB plywood, and get the best cut available. I’d be backing the bottom of the plywood up with scrap, so I wouldn’t expect to get much chipping on that side even if I do come through it with the downcut bit.
The problem with using a downcut bit all the way through, is the degree to which the downcut bit packs the kerf. But if the bit reversed after 1/16" or 1/8", I’d think it could still evacuate chips.
This wouldn’t technically be a compression but, more rather an expansion bit (I’m coining that phrase). A downcut bit with optimized chip removal, as it were.
Hmm… so, what we really want is a bit with a somewhat downcut actual cutting flute coupled with a more emphatic upcut-like flute (continuous or segmented) that is slightly undersized so as not to actually cut into the stock. It’d work like a single-flute downcut bit as far as cutting, but like an upcut bit with respect to chip evacuation.
This is what a compression bit looks like (this one is single flute, it’s easier to see) - which is sort of the opposite of what you want as the others have pointed out.
