So here's last night's handrolled and tonight's CamBam-generated.

So here’s last night’s handrolled and tonight’s CamBam-generated. I’ve discovered that 40mm/min with an ⅛" endmill is too fast (especially with 0.4mm cuts). Even 0.2mm cuts had chatter. The 0.4mm cuts were a mistake, I didn’t doublecheck the settings in CamBam. The right-hand slot is crooked because my Z axis is not very stiff in the Y direction and it deflected with the deep cuts.

I managed to repair the slot using a ¼" endmill, which worked fine at 40mm/min, 0.2mm depth.

This isn’t pretty but it’ll do the job.

Wow. Yeah, that’s brutal. Milling aluminum is not easy. Your first milling job at the bottom looks really good compared to tonight’s. The rigidity on Shapeoko is not super awesome, so that’s why I think aluminum milling is so hard to do on it. What if you go back down to 10mm/min?

I know! Sigh.

Yes, next job I’m going to try at 10mm/min and 0.1mm cuts. At least I have a verified data point now.

Gordon, would you be up for sending me your Gcode? I just got my 3040 running and I want to do a comparison mill of aluminum on it just so folks in the community get a feel for the differences out there. I’ve never milled any aluminum on the 3040, but I’m dying to give it a try. I’m hoping I can get 100mm/min with a 1/4" endmill but we’ll see.

No probs. I’ll give you two: one for the groovemount pocketed with a ¼", and another for the screw slots pocketed with a ⅛".

@Gordon_Broom what cnc/spindle are you sporting?

It’s the inventables 300W spindle on my ShapeOko 1.