aluminum

is it possible or has anyone ever machined pieces out of aluminum? Just curious.

All the time! I made a video about it: [youtu.be]

very nice. I wasn't thinking anything that thick by any means but nice to know. Is there a place that maybe has a list of different materials and different bits and the recommended speeds for them?

I am just now getting around to my first aluminum project. I am using a double fluted 1/4" up-cutting carbide bit on some .1" thick aluminum to make some trim rings. Can you give give any help on feed/speed rates?

The double flute is going to generate a lot of heat and lead to aluminum buildup on the bit. I’d recommend an “O-flute” (single flute up cut) but for aluminum. However, if you wanna try with your current bit I’d recommend some kind of lubricant. WD 40 evaporates quickly and pulls away heat. I’d run the cut at 2 ips with 0.01” passes

I agree with Brian on everything except I've never had good luck with lube including WD40. It tends to make chips stay in the grove and get recut.
(as always, take both sides and find what works for you)
I blow on it with compressed air to both cool and clear the chips.

How much luck you have after proper setup is much to do with the aluminum itself, some formulations do quite well but others gum up horridly making it almost impossible to cut.

so it sounds like I am off in the wrong direction. I got some .1" thick aluminum plate and thought the softer 3003 would be better. I would assume this is probably one of those alloys that I should not use. I did order some of the O-flute bits after watching a video about it. I have some cutting oil or wd40 I could use.

6061 will be the best alloy to cut. A little harder and forms better chips. 0.1” is pretty thin—so you might be able to get away with it—but I think you’ll find 6061 much more pleasant to work with.

any suggestions on how to mount it? Assuming I will be using oil on it I am considering how to make a mount for it out of hdpe or something similar so it will not degrade the spoil board over time but not sure what is best.

A piece of scrap wood will do fine. It is is large enough to sit the handibot on you can drive a few screws through the holes on the front/back of the handibot base to secure it to your sacrificial board—then screw the aluminum down to the sacrificial piece as well

I finally got around to starting this. I got the aluminum mounted, homed the tool, zero'd the Z and got started. I only did a light test pass .02 deep the first time to see if the feed and speeds were ok and it looked nice. I went in to do the full cut and for some reason now I can't get the tool to go below the zero point on the Z-axis when its cutting. It shows that its lowering when its moving but as I watch the bit it never gets down to the material surface. I tried re-zeroing the z a few times, checked to make sure the bit was tight in the router and the router tight in the cnc and it all was. I can manually move the tool past the point while zeroing it but when its in cutting mode it seems to stop right about the surface. I bumped the cables that snake up to the router/z motor while I was changing bits but that was before I started so I am not sure why the test pass was ok the first time. Now when I try it it again it stops short.

What does the preview in vcarve look like? If you’re doing 0.02” passes, you should see a bunch of blue lines tracing out each pass, going down into your material. Good to confirm that you’ve got something that looks right in preview.
Also—how do you have your aluminum mounted? Sometimes when I am cutting aluminum, I’ll use a small vise. I’ll zero the tool off to one side and it will be able to make the plunge. But once I’m over the vise, the aluminum plate behind the router bumps into the jaws of the vise, preventing me from getting low enough.
You could also try shifting the router slightly lower in the bracket. If it continues to stop exactly at the surface even after changing the position of the router in the bracket—that would be very strange.
Feel free to post your sbp file here as well for me to look over.

the preview shows it going down .02 per pass the way it is supposed to. I have the aluminum mounted down to my spoilboard with two 1/4-20 screws and it is not moving. I know that it has the room to go down further as I can move it down on the screen enough to go past the material. While its cutting it shows on the screen that its going down but it never goes past the 0 point for the Z. Last night after some thought the only thing I didn't do was to power it down and see if that helped but other then that I am stumped

Today I tried unplugging it, removing the router to be sure there wasn't anything blocking it, rezero'd it a couple of dozen times and for some reason the Z-axis is drifting from .02-.08. Every time I ran the program it was off a bit and sometimes even just raising and then lowering it caused a difference. I checked the software update but it said I was current. Any help

I was finally able to finish up the little part I was making but not with out cheating. In the end I had to zero the Z-axis at what was a -.06 to be able to get to the bottom of the aluminum. Is there a chance it has to do with the fact I had to create the cutting bit parameters for the 0-flute for I got for the aluminum?

sorry for the repeated posts but I have been working on it and thinking about it in between. Today I think I figured out that I was just not being aggressive enough with how much material it was taking out. When I cut the number of passes in half it started to work better and then by removing a few more it was throwing chips everywhere. This will be the flashing led when the alarm in my car is on. I have been making other things that were similar in design but I always use an acrylic trim ring instead of aluminum. The aluminum looks 100x better.
[www.youtube.com]
security led



Edited 1 time(s). Last edit at 08/08/2019 05:54PM by cuervo.

how about copper?

Copper is very soft and doesn’t want to form good chips when you cut it—it will kind of deform around the bit, making for a really lousy finish. This is where something like WD-40 is helpful..not as a lubricant but as a heat absorber—the evaporating liquid will help keep the copper cool...and you’ll need to make really gentle passes.
There are some copper alloys that are better for machining like 145 copper — if you don’t already have the material you plan to cut from.

I have already learned how helpful a syringe of cutting oil is with aluminum and figured it would be helpful here as well. I assume the same o-flute for aluminum is good for copper as well?

Yep that'll be your best bet!