I finally waited for my a350) Very satisfied with the 3d print, successful tried milling wood. I want to try milling an aluminum plate, but I have no experience at all. Tell me how to choose bits, how to choose the feed speed and what are the nuances when working with aluminum?
On A350, there are no nuances: Just Don’t. It’s a very light duty machine, with a small milling motor that matches its not-very-rigid frame.
My general advice for CNC milling of metal, aluminum included, is that you should know something about manual milling first. You don’t need to buy your own machine to do this; taking a class somewhere is adequate. It’s very easy to spend a lot of money on broken tooling, broken fixturing, and broken machines when you’re a newcomer to metal cutting and self-teaching.
And the SM2 is a very expensive machine to break testing it out on somthing its really not designed to cut.
Step One: Unplug SM.
Step Two: Push it in to the corner.
Step Three: Use a dedicated CNC that’s made for milling aluminum.
Hahaha y’all have no chill. Lmao.
I think with an engraving bit you could have success. Maybe even with an endmill doing miniscule engagement.
@Freimor If you want to learn about desktop CNCing one place to start would be to read through this guide for the Shapeoko: https://shapeokoenthusiasts.gitbook.io/shapeoko-cnc-a-to-z/ It will give you a crash course in milling in general, and can serve as an introduction to many new topics you can research more. There’s no simple answers here though, there’s a reason CNC operators can earn up to $30/hr or more.
I’m willing to push my SM as hard as anyone and try it on any material (and have) but there’s some things it just can’t do.
Engraving on aluminum is one thing. Actually milling it is another.
There are different levels of hardness within aluminum, so it is probably possible to mill some varieties on an SM.
My biggest concern would be cooling. I’d want to add some sort of air jet. Not sure if that would be enough. With the placement of the y axis modules I wouldn’t even start to try water cooled.
As with anything on the SM, feel free to try it with the understanding you may be purchasing some replacements parts that won’t be covered by warranty.
Man, it is funny that this is coming up on the SM forum and the FB forum at the same time. Uhh, so yea, I am not willing to experiment with milling aluminum on this machine myself, BUT…! (here it comes…) Today, while browsing the FB SM channel, I stumbled upon this gem today (not my picute) -
Also, it was accompanied by this picute (I am guessing the settings used) -
(Good thing my membership updated on here so I can upload multiple images now!)
Anyways, I am one of the people who took a CNC class, and as other users have commented, they type (hardness) of the aluminum makes a huge difference, also that heat is the enemy. I do think the SM could do aluminum given enough time, and I mean SLOOOOOOOOWWWWW IT DOWN!
But, I just had to comment, if you’re gonna try it, please keep us up to date with your progress, also please note any observations you make, noises, temperatures (especially of the module and linear rails), pretty much anything you notice. I hope this helps get you in the right direction! Best of luck!
5 years later…
From what I understand you don’t want to slow it down.
You need to keep the tool moving and creating chips. Go too slow and you’re just creating friction and heat.
On the link from @brent113 that had examples they were running 600mm/m.
Yes and no, again it depends on the hardness. What you’re referring to is called sloughing, it is where the heat is concentrated in the discarded material (most common with brake pads which is why surge braking is preferable when heavy). Your bit should be sharp enough to cut the material rather than scratch it, the speed that you move will be dependent on many factors, but slow is relative, you can work fast, with more steps, like here, the goal is to reduce the stress placed on the machine to an acceptable level while still getting the job done. Also, CNC milling is very different than say sanding or filing: in those, for fine movement u push lighter which makes more friction like you’re saying, but in CNC the torque is at maximum until the destination is reached, so the force is the same fast or slow, you’re controlling the size of the chips you’re creating (and the surface area that must be cut to remove each chip).
I’ll note that this guy does seem to know what he’s doing, because he says a number of things that machinists talk about that novices do not. One is his selection of a four-flute mill for heat removal (I doubt heat removal is a limiting factor here, but that’s beside the point). He says right at the outset that he’s using a soft aluminum. He did not, however, state what alloy he’s using. Just as well. If you don’t know “soft” means here nor how to obtain it, you probably should be trying this.
I was genuinely surprised with his (to a novice at least) seemingly aggressive feed rate. He got excellent results considering the flexibility in this large gantry system.