Cut my first piece of aluminum with my ShapeOko and ChiliPeppr. Unfortunately half of 13 is not 7.5 so I need to recut. CP is the best interface to GRBL bar none!
Nice. There’s always a lot of questions as to whether Shapeoko can cut aluminum. It looks like you pulled it off. What feedrate did you use? What type of endmill? I assume it’s the softest aluminum?
that’s a great cut. I have the same questions as John. 
It’s the standard 1"x⅛" bar stock from Home Depot. It’s pretty soft, I don’t know the formulation. I’m using the Inventables BLDC spindle on my ShapeOko1, and an Inventables ⅛" endmill. I was taking .2mm deep cuts each time, and a feedrate of perhaps 8-12mm/min? I was playing with the feedrate adjuster on CP but I didn’t see things change. 10mm/min would probably be OK. I used WD-40 as a cutting fluid every so often.
The ⅛" endmill did chatter a bit, if you can get away with it use a thicker mill (I needed the thin one for the 4mm slots).
When I recut this I will verify what feedrate I actually use. Because 8mm/min seems too slow (based on how long it took me).
FYI, unless this has changed, the feedrate control is interpreted at the start of the job, and not re-interpreted during the job.
Aha @Kevin_Hauser that explains it. Thanks. So I really have no clue what feed rate I was using. Trying again tonight…
OK, so tonight I used CamBam to create the gcode instead of hand-rolling. Results. 40mm/min with a ⅛" endmill is too fast at 0.2mm depth cuts. Really really too fast with 0.4mm depth cuts. With a ¼" endmill 40mm/min and 0.2mm cuts are fine.
Gordon - What wattage spindle are you using? If you plan on doing a lot of this, you might want to invest in a laser tach so you can measure actual spindle RPM under various load conditions. Great info, by the way
It’s the inventables 300W spindle running at 48V. I have not hooked it up to a PWM pin so it’s still in manual speed mode. Although I was running it full out.