I do a lot of sign hand carving and want to use my XXL to simplify the initial rout. For the initial cut, I have been using the Amana Tool - 46282-K CNC 2D and 3D Carving 5.4 Deg Tapered Angle Ball Tip 1/16 Dia x 1/32 in a handheld router, cutting boxwood or jelutong at 1/2-inch depth and finishing with gouges.
With the handheld I have been doing the entire 1/2-inch cut in a single pass and it has worked well, but from what I have read, it sounds like this will need to be done in multiple passes with the Shapeoko. Since I am brand new to CNC, can someone please give me a “starting point” for cut depths and feed rates for something like this (stolen from another poster as an example)? Thank you:
18.000RPM, 1xD depth per pass (so 1/16" here), 40ipm, granting a chipload of 0.0005" (which is reasonable for a sub-1/8" tip)
If that works, you could then incrementally try deeper depths per pass (and faster feedrates, there is probably scope to almost double it with no ill effects), since those tapered endmills are actually much more rigid than a regular endmill of the same diameter (1/16" in this case)
I like to think of tapered endmills as a middle point between a regular endmill the diameter of the tip (1/16" here), and a regular endmill the diameter of the shaft (1/4" here), so when selecting feeds and speeds I will go for something in between the excessively conservative values required to run a 1/16" endmill without breaking it, and the brute force values that one can use with a 1/4" endmill. In-between, but still steered towards the small diameter end of the tool. Hopefully this is not too confusing.
Experimentation is key, I would start with 18K / 40 ipm / 1/16" DOC, and then bump settings until it sounds like the machine/cutter is struggling.
