First Successful Cut in Aluminum Figured I'd share it

(Richard Patterson) #1

While the part isn’t pretty, that’s almost entirely due to in being some scrap aluminum plate I had. So ignore the random half cut hole, scratches and gashes in the surface. But I’d like some feed back on the finish where it was actually cutting. The 2 intentional holes were 8.1mm and they came pretty darn close at 8.07mm (± .02mm). I haven’t set up any air or vacuum system yet so I sat there vacuuming the chips as it cut. (Ears are still ringing, the 2D contour cut for the profile can make some serious noise). My speeds and feeds were 10k rpm, 20IPM, .01" step down. Used F360 pocket and contour. Total time was approx 32min. The stock was 3x6x.375", the part is 2.75" across, .625" thickness, and then full depth of the stock (.375"). If anyone has any tips or comments let me know.

(mikep) #2

It’s a great start!

(Richard Patterson) #3

Great thank you! For those 2D contour cuts where the cut is the full diameter of the end mill, serious noise is to be expected correct?

(mikep) #4

Well, depends. Usually that indicates chatter, and looking at the cut, that’s exactly what you’ve got going on there. Try reducing the feed rate. There’s a balance to be had around depth of cut, width of cut, and feed rate. It can be hard to find and depends on so many things I can’t just tell you “The answer is…” but the nomad feed+speed chart is a great place to start. the nomad takes some patience to get through things like this.

(Neil Ferreri) #5

I’d avoid that when possible. Clear an area wider than the endmill, so you’re never slotting or cutting in both sides of the endmill.

(Richard Patterson) #6

Okay good to know. I thought it seemed loud, and “from looking at the cut” you’re referencing the “wrinkled” or rough look it has. If you look at the top photo, the very top portion has a more mirror finish (which is actually the bottom of the part). I’m new to CNC/CAM so maybe did my finishing pass only pertain to the very bottom (top of picture orientation wise). Or could it have been that with that little material left at the end, that it was putting up less of a fight for the mill to cut through? I’m just analyzing it from my amateur perspective.

(Richard Patterson) #7

Good to to know, so should I plan on milling parts with the intent to mill away the entire stock from the outside? I only say that because I would assume that to cut any part from a plate, at some point you’re going to have to be cutting full diameter of the endmill, unless you machined it in multiple stages?

(Neil Ferreri) #8

No, but a 10mm “slot” for a 1/4" end mill gives you room for adaptive clearing.

(Phil Gorsuch) #9

Second that. Usually takes some mucking about in F360 but do a narrow adaptive around the part with enough space that the mill sweeps across the slot face instead of just contouring around it.

(Richard Patterson) #10

Sorry for the delay in responding, busy week. That makes a ton of sense thank you!