Crossing streams
I think this is the core discussion thread for this topic.
I’m trying to figure it out too.
I have a linked dicussion at Repeatable process for setting Feed Rate and Depth of Cut in Easel and elsewhere with a spreadsheet calculation tool that may or may not help.
your situation is … interesting,
The guidance so far has been to experiment with materials and zero in on what your machine can do.
We’ve documented in the spreadsheet the ideal speeds/feeds for the spindle rates for the deWalt: an XCArve cannot acheive the optimal settings so you are left with a need to compromise in one of several directions.
if you think of feed rate, depth of cut, and spindle rate as an iron triangle, all inter-related,
then I guess it looks like this:
- The spindle on a deWalt goes at 16k RPM minimum.
- The feedrate for a spindle at that rate is unachievable, so go as fast as you can: in a hard wood the target rate is somewhere around 60 inch per minute if that is achievable
- to push the spindle faster, make depth of cut shallow. The rule of thumb is half of your tool diameter: for a 1/4" bit use a 1/8" DOC, and do so on.
The easel program uses preset feedrates and DOC based on the material.
these are in the spreadsheet.
I am still trying to make sense of them;
they seem arbitrary if you consider material hardness to be important.
for instance, here is a list with the hardness rating for the woods:
Two woods with very different hardness ratings will have the same settings.
This implies the settings are a bit arbitrary and experimentation is required to get it optimal.
in this context, tool life is going to be difficult to optimize for.
we are running tools at the wrong speeds to keep them cool, so the bits will burn out sooner than in a more controllable situation.
there seems to be an assumption this is unavoidable;
the advice is to buy the clearing bits in 10 packs,
and be very deliberate in the settings you use.
I hope this helps.