I’ve been using a spreadsheet I found here in the forums to do some feed rate computations for my Dewalt and realizing that, in my first days, I was definitely running the bits at too high RPM and too slow for the feed rate. I was getting fine sawdust. Now that I’m decreasing RPMs and increasing feed rates, I’m getting what I assume to be the lovely chips people describe. It’s also taking far less time to cut my various test pieces.
One thing I’ve been working on as a project requires some facing to thin down the wood to the proper thickness. I was using the 1/8th flat end mill I already had in the collet to do the facing and the initial cutting. I realized later that I had a 1/4 flat end mill I could use for the facing portion to speed things up. I did some calculations and came up with what seemed a rather high feed rate (285 perhaps?), but I decided to see what happened. I put it in Fusion 360 as in/min and it comes back with the metric calculation (since I default to metric). To my surprise, the actual rate of movement appears to be much slower than the former 1/8th end mill. The last cut uses a 1/16th end mill and I had kept the 1/8th feed rate settings… it appears to be insanely fast.
So… I assume the feed rate / surface speed relative to mill diameter represents amount of material CUT per minute rather than being the raw speed of the X, Y movement of the spindle? Or am I misreading something?