I read up a little and I don’t see how finishing it with a vee would solve this. What am I doing wrong?
This is 1/16th anodized aluminum that came in a sample pack for a laser engraver. Perhaps it’s the wrong material? Any suggestions where to buy thin and colorful aluminum sheets?
Is it the toolpath? The end mill? The direction of the cut? I want to cut out little letters and it cuts just fine, except that it’s obviously not.
I stopped the job when it went back to cut out the center of a letter (inside cut), and it lifted the metal with the bit and I had to stop the job. I was using tape and CA glue. I’ve seen the machinable fixturing wax, is that the best solution for holding small bits?
That looks a lot like my first attempt cutting aluminum i cut lots of things from thin aluminum sheet and still struggle a little with that perfect recipe. A few things that should help alot…
Know the alloy you’re machining. 6061 often gets recommended here as it machines quite well. Softer alloys are near impossible to cut well and often results in what you’re seeing in your photos.
Single flute endmills are also the way to go. Multi flute endmills have a tendency to get clogged with chips resulting in poor cut quality.
Keep the cut channels clear of chips with a air blast or somthing similar. If the endmill recuts chips you start running into issues like you’re seeing.
I wouldn’t give up on tape and glue for your workholding, i pretty much use it for all my projects and it works well. Are you using the name brand scotch blue painters tape? I only ask because i tried to save a few bucks once by buying some no name tape at the dollar store and it didnt hold well at all and my stock pulled up during cutting.
I use the Scotch Brand plain old painters tape. There are many different types of 3M painters tape but the plain old blue 3M Scotch works best. I use Titebond Medium CA Glue. That has worked best for me. The thin tends to run more than the medium. You will have to do a trial and error to get the right amount. You want enough not to spread out too far and not enough so the parts come loose. With the medium it stays where you put it but flattens out when you put the material on top. I buy the 2" tape and make sure the edges butt up against each other and NOT overlap. Just match the pattern on the material. I squirt out the CA in an S shape about the center 3rd of the row of tape.
Knock on wood, I have never had the Scotch 3M plain old painters tape and Titebond Medium CA glue fail me. As others have said I have used on 100’s of projects. The only issue I have ever run into is really big projects. It takes a lot of tape and glue so I usually use my long L bracket and cam clamps to secure really big projects.
Another thing is to use bottom of material instead of the top. This method keeps my spoilboard from getting cut up. You still need to measure your project properly. I measure the material but after the painters tape and super glue are applied I measure it again with the calipers from the spoilboard and go back and edit the CC file before cutting.
I engrave and cut out a lot of Christmas ornaments every year out of this stuff. The #102Z and #274 work great but I find the #274 does give you a cleaner cut. As everyone else mentioned, tape and CA glue under the entire area to be cut and outward a little, just in case.
When I started cutting aluminum sheets like this I was using a light air blast from a hand held blow gun to clear chips and spraying a drop or two of WD40 ahead of the cut. That worked for a clean cut but I found that the WD40 had a tendency to loosen the tape under my work piece. I later went with a air blast alcohol mist setup and never looked back.
Thanks. This is really fitting because the blue sheet in the picture is from the link you sent me!
Good to know I can make this material work. My new end mills arrive today. I have air built into my table but haven’t configured it yet. It sounds like I can manage test cuts with alcohol and compressed air right from the hose.
My CA glue experience so far has been perfect, but as mentioned throughout this thread, covering it all is vital. Previously I wasn’t making these small cuts, so I went for the less costly approach of adding “just enough”. Lesson learned.
I bit the bullet when I started and got a 6 pack of the 2" good blue tape. Was hoping I could find cheaper glue than the medium Starbond I have, but it seems these are 2 essentials that shouldn’t be skimped on.
This forum is amazing. I look forward to contributing more as I pick this up.
When you say to “cover the entire area to be cut”, are you mentioning taking care to cover the bottom with that tape, or is the top also in need of treatment?
Sorry my reply was unclear. The tape and CA glue should cover the entire bottom surface. I use cheap tape without issues. You can’t really find bad CA glue in quantities larger than the tiny kitchen drawer tube, but I use starbond, stick-fast, and I think fastcap with success.
The main thing with aluminum is the chipload. You need to run faster feed than what you might think.
Your anodized layer is slightly harder than the base material beneath and can cause the bit to dull quicker than just milling plain 6061, in my experience (I do a lot of anodized aluminum on a Bridgeport). As mentioned above, I also use a diluted mix of Isopropyl and water in a spray bottle to help lubricate, cool as well as knock down the dust. First pass cuts are skim thin usually around .002, just to get through that anodized layer.
The first place to start is what actual alloy of aluminum it is. Some is super gummy and hard to dial in. Most thin sheet aluminum is 5000 series as that alloy is designed to be better at bending as sheet material often does. If that is the case, it really needs a single flute, fast feed rates, and low depth of cut. I have cut it on my S4Pro before, but it took a few cuts to dial it in.
Also, the adhesive workholding is as good as it gets with sheet goods unless you go vacuum table.
i cut lots of things from thin aluminum sheet and still struggle a little with that perfect recipe. A few things that should help alot…