After owning my machine for a few years I was never quite happy with it’s performance in aluminum, so I threw a little money at it to see if I could get some satisfactory results.
8" CNC4Newbies Linear Z-Axis w/ fast screw - direct drive 270oz stepper
9mm belt upgrade (thanks tbd!)
270oz steppers all around
2" Y-Axis lift with braces (thanks tbd!)
Makita RT0701C Router
Bit - Destiny Tool Viper DVH 1/4" #V21624S (1.5" CL, 3.0 OAL)
So, after some discussion with Haldor, I made a simple toolpath in Fusion 360 for my first test in aluminum.
It’s a very simple set of pockets, 0.20" depth, with each of the three at a progressively deeper depth of cut. The pocket starts at a 0.02" DOC (0.5mm), and moves to 0.03"(0.75mm), and finally 0.04" (1.0mm). This is a roughing 2D Adaptive clearing toolpath without a finishing profile, so the edges will look a little rough.
Pocket 1 (0.02")
Pocket 2 (0.03")
Pocket 3 (0.04")
All Pockets Completed
It should be mentioned this is a specialty bit with an extremely long stick out (~2.0") which probably has some blame in the final finish, as I expect it increases whatever flex and runout my spindle has.
Overall it would seem a DOC of 0.3" seems to be the best looking finish of the bunch. I did notice chatter at 0.4" DOC, not sure if I want to push it any further with this particular bit. I will pick up a much shorter bit for profile and slotting work as this is definitely not ideal. I wanted to get peoples opinions on what I could improve, and how it looks so far.
Ultimately the purpose of these upgrades and this particular bit is to machine a FCG pocket in an AR15 receiver, which is about 1.25".