Let’s start with the obvious. I’m not a videographer. I’m not a machinist. Yes, this was REALLY aggressive.
I figure as long as things don’t break right away, I can figure a reasonable recipe and tweak from there. Plus, it’s a lot easier to convince myself to back off when things aren’t going well than to get more aggressive when they ARE going well. I tend to be more of a “If it ain’t broke don’t fix it” kind of guy.
Endmill is SpeedTiger coated 4fl, and they suggest something like
Sidecutting
13k RPMs
0.0003"CPT
0.375" DOC
25% stepover
Slotting
10.6k RPM
0.0003"CPT
0.050" DOC
Here, I used:
Sidecutting
16k RPMs (Limited by Dewalt)
0.0003"CPT
0.18" DOC
25% stepover
Slotting
16k RPM (Limited by Dewalt)
0.0003"CPT (50%stepover for extra roughing pass)
0.010" DOC
I’ve got some small aluminum parts to mill coming up, so I’ll post those here when I get to them.
Ultimately, I think ramping down the tabs was too much, but there is a small possibility the endmill just started to pull down because it was so short (see the end of the video) and caught on one of the tabs as it backed up to start a new ramp.
It was really taking some bites out of that steel on the adaptive! Then the endmill just…broke. I had enough to grab on to, and the flutes looked OK, so I chucked it back in and started over!! Went really well for a while. Slotting took time but no real problems. The little chips were super hot when they hit my arm but the stock didn’t go over 105F and was usually between 90-95F. I thought I was showing my thermometer to the camera, but remember what I said above? Yeah, sorry.
I really didn’t expect it to cut far at all, but I think taking adaptive stepdowns to 50-80 thousandths is a good idea, and the RPM/Chipload seems adequate, given the final condition of the endmill. I think I always knew I was going to be better off with adaptive over slotting, but I really wanted a torture test here (and I got it).