Milling VERY THIN aluminum .025"

I’ll be transparent right away, I’m a total rookie and haven’t even run a job on my Onefinity woodworker yet. I have a potential client asking about needing aluminum “tags” for telephone poles. The sheet aluminum I think I would use is laser-friendly and incredibly thin at only .025" thick, and I planned to use the CNC to cut out the tags and then put them into a template in my laser for engraving.

Can anyone lend insight on what type of bit should be used for such thin Aluminum material and potential feeds/speeds? I was looking at these bits 'O Flute' Spirals - BitsBits.com – For that matter, any advice at all would be greatly appreciated… methods for holding down such a thin work piece, tabs or no tabs? I want to do it safely but in an efficient timeline as well.

Thank you so much -
Christy

Those bits look pretty good, I believe they would do a good job for you. I would stick with a small diameter like 1/16".

As far as hold-down, that could be tricky. I use 2-sided tape extensively, but on that thin of material it would deform it trying to unstick it. I’m thinking a vacuum puck might serve you well, but that’s not really a very inexpensive solution, depending on the volume of tags. Do the tags have holes in them? If so, that could simplify things a bit by making a hold-down plate just slightly smaller than the outer profile of the tags. You’d have to process the holes first, then screw down the hold-down plate & tag onto a fixture plate.

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Any reason why you would choose 1/16" over an 1/8" bit? I figured the 1/4" was overkill.

That’s a great point you bring up about potentially bending the material if I used double sided tape. The tags do indeed have 2x 5/16" holes in each tag on either side. That sounds a little bit too laborious to utilize the holes for hold downs but sounds like an interesting idea if nothing else comes to light.

I would use a stubby 1/16" because it will easily cut through that material. You can use 1/8", but no need to remove that much material just to cut the profile (double the mess).

Not seeing much option aside from utilizing the holes for hold-down, unless you want to use tabs, but that would ultimately entail more labor than a well-made fixture plate. What size is the tag itself, and what size is the starting material? If you’re going to make hundreds of these, I’d make a punch fixture for the holes.

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I appreciate you sharing your expertise with me! That’s a great point about bigger bit = bigger mess. Thank you.

I really don’t want to use tabs considering what a nightmare that would be to clean up. The tags are 4"x2" with 5/16" holes and the starting material is 24"x12" so I have 5 rows by 5 columns of plates with 2 vertical on the side fitting 27 per sheet. There would be potential for me to make hundreds for sure… what is a punch fixture?

Again, thank you for all your time and help!

Christy, look up AluMark, It might be a better option. I have done a bunch of nameplates for doors/desks for teachers and staff at my school and it’s easy to cut and engrave. Ran them on a 30w CO2 laser cutter.

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Since you have the potential for a large volume of these, it would pay to build a custom vacuum holder that could work with both the LASER and CNC.

Is your LASER a separate machine or are you using something mounted on the 1F ?

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Agree on the stubby bit.

Glue the aluminum to a substrate/waste board with liquid hide glue. Let the glue dry thoroughly, clamp the assembly onto the OF bed, and cut it. When finished, soak the substrate and workpieces in warm water. The glue dissolves and you lift the aluminum off without bending it. Of course you throw the wet substrate/waste board away. I would consider using thin mdf or fiberboard for the substrate.

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Christy, envision 2 steel plates sandwiched together with a narrow gap between them (wide enough for the alum. tag material to slide into). Then there are (2) 5/16" holes at the proper spacing for the holes. Now you use a 5/16" dia. punch and smack it with a hammer to create the holes. Honestly though, I don’t think I would do it that way after all… too much extra time in that process.

Now let me ask you this: since these are just utility pole tags, perhaps they would allow some size allowance? If they could tolerate being slightly smaller, you could run 36 in a sheet with no waste. In which case, you would do all the holes first, then cut on the lines to cut out the tags. Then, and only then would I probably use carpet tape and gently scrape them off the table with a putty knife. This would be the most efficient production method.

I will be honest here… this does not sound like a great way to make tags. Once they’re all cut out, now you need to deburr all of them (regardless of cutting them 36x undersize or not). In production, these things are normally stamped out dirt-cheap. The CNC method may be alright to make a few, but it is not a great method to make them in general.

Another idea would be to have them supply pre-made blanks. Then all you have to do is laser them. In general, you can’t compete with how cheap you can buy blanks by the 100’s.

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Agree. Use precut blanks or I would investigate some alternate raw material that required less machining on your part. Ditch the sheet material and find some roll material of the proper width. Then just cut to length, punch your holes, and toss it under the laser using a vacuum fixture. The top surface is completely free of obstructions and you are free to work any area of the tag.

You could automate the whole process IF there was a large enough sales volume to warrant investing the time and work to set it up.

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Great point, Bob! Starting with 2" width material is a good processing plan. Even without hole punching. Machine 2 holes, cut 1 edge. Wash, rinse, repeat. Still not a job I would want to make potentially hundreds of though.

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Use your CNC to machine a die to cut and punch holes in one operation.
Build a machine to mount the die in with the capability to feed the roll material into position. Then drive the die with a pneumatic cylinder. Shouldn’t need more than 90 PSI to make it work. This is .025" Al so should be easy to cut and punch.

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I have heard of AluMark or AlumaMark but didn’t think it could be cut on a CO2 laser… I have a 50 watt Epilog. Did you get yours from Johnson’s Plastic Plus? If you don’t mind sending a link, I would be super grateful.

I have a stand-alone Epilog laser so it already has a vacuum table.

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Yeah I wasn’t sure if the aluminum would need any post-processing clean up or not. I did look into buying blanks but it does indeed have to be aluminum and exactly 4"x2". Not sure why they are so strict with their dimensions. Do you know of a good resource for custom sized aluminum blanks? My laser is quick and I know it like the back of my hand whereas the CNC is all new to me.

You’ll be laughing with 50w! Super easy to cut. I will ask my teacher where we order the stuff from, and get back to you. Engraving and cutting with one fixture setup will be wayyy quicker than CNC’ing and then Lasering.

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I want to get excited but I have never heard of anyone laser cutting aluminum with a CO2 laser… engraving AluMark, of course! Cutting…? Nowhere on any of the suppliers websites does it say you can cut it. Hmm.

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I could be wrong. Maybe it’s not brand-name but it sure cuts nice. I’ll take some pics when I go to school later today.

Try The Ring Lord. He does lots of aluminum blanks.

http://www.theringlord.com

His closest stock item would be 2" bracelet blanks. He sells those in 7" sections but also sells it by the foot. He does custom stuff too so likely able to get you 4" pieces.

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Hey Christy,

found this interesting:

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