I’ve been doing test cuts to see how fast I can successfully cut redwood (which yes, is very soft): I have plans to do a piece a good 20" wide x 30" long x 1" deep, and based on my current speeds & feeds, my time estimates are… large (like, do roughcut for 9 hours day1, pause the machine overnight, finish pass for 12 hours day2). So I thought I’d start doing some test cuts to see how fast I can push the machine and still maintain quality. My findings (so far) are below, but I’d love to hear what others have done.
I’m using a .25" 3 flute upcut ballnose for my rough and finish passes currently. On all tests, DeWalt has done fine set at speed 1: I start it faster concerned that I’m going to fast, but slowly dial it back to 1 in the first minute, and just leave it there.
For rough cut, I’m cutting .125" deep with a .125" stepover (1/2 bit width), leaving .125" of stock behind.
For the finish pass, I’m doing a .025" stepover (10% bit width).
If you’re wondering, the test pieces were modeled in Autodesk Maya, and gcode generated via MeshCAM.
(Edit: Based on below comments, my plunge rate is actually being limited to 20"/min)
My first test was done with the roughcut at 120"/min feed & 60in"/min plunge, and the finish at 150"/min feed & 120"/min plunge. This piece took 50ish minutes, 4.5" x 8", 1" max cut depth (mainly for the votive hole) :
(the crack you see is from the reclaimed wood, not the cut)
The machine didn’t even blink, so I did…
My second test: Roughcut at 150"/min feed & 60"/min pluge, with finish at 180"/min & 120"/min plunge. This piece took 30 minutes, 4" square, 1" max cut depth:
And again, in both cases the machine seemed to have no problem, even with the DeWalt on 1.
I know using a 3-flute is greatly helping the speed, and I plan to push it even more… but I’m wondering if there is an actual maximum for the machine? I’d love to just jump ahead to some known good numbers rather than doing this step by step, as entertaining as it’s been.
Any thoughts appreciated!