I’ve been cutting out signs lately (different species of wood and not every wood does this and I understand different species act differently and that’s understandable).
That said, my FnS and all that hasn’t changed much - as most of the woods I’ve been using are similar on the JANKA scale - but I’m just hoping there’s an answer to a more “smooth cut” without seeing that passes of .08 DOC I’ve been doing on the signs. (This photo is obviously the edges of the sign. (This is the center of hardwood boards and not end grain, FYI).
The first couple of signs I was using a Amana Tools #46202 Downcut.
Yes, the lines are very consistent all the way around (all parallel to one another all the way around the piece).
I tried a downcut and it wasn’t as noticeable IF barely at all but then I did the same sign (although it was a different species of wood - so that’s why I didn’t know if that could have been a thing) and that next sign (again, same design) was done with the compression bit I linked above and I was getting those lines.
Here’s the metadata from the sign with the downcut where the lines were NOT noticeable
A compression bit is upcut at the bottom, so I would expect a compression and an upcut to leave similar lines.
It looks like the wood is tearing (rather than shearing) at the bottom of the bit. It may simply be the nature of that species. Are you sure the bit is sharp at the bottom?
I don’t think stepover is a factor here, that comes into play when cutting a pocket wider than the bit.
Is the path you are taking a simple contour cut? That ends up being a ‘slotting’ cut, and that can be hard on the bit.
A couple of things you might try:
Initially, cut oversize, say.01" (1/4 mm) to .02" (1/2mm). Then run a contour cut right to the desired size to remove just that. Since you are removing so little, you may be able to have a higher DOC (so fewer passes).
Rather than cutting a contour (which ends up being a slot), make a pocket around the outside edge about 1.25 to 1.5 times the width of the bit, and cut that. This will reduce how the walls of the cut interfere with the bit.
