gomex design inc.
New Member
im getting ready to cut 3/4" aluminum on a Multicam M series and using onsrud 1/4" bits (63-622). any suggestions, as far as RPM and feed rate and/or how many passes I have to do?
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3/4" aluminum
- Thread starter gomex design inc.
- Start date
SebastienL
New Member
Send it to have plasma or waterjet cut. 3/4" is a little thick for a router imho.
SebastienL
New Member
Oh, and welcome to S101...
Biker Scout
New Member
3 or 4 passes, coolant or forced air on the bit. You should be fine. There is an average feed rate for cutting aluminum, however, I do it by eye and the shape of the chips. Should be coming off like little "C's"
theskipman_98
New Member
First thing I see is the bit is exactly 3/4" CEL. The bit will end up shouldering on the last cut (assuming multi-passes ). After you take into account for the over all of cutting through the material and a little into the mat, the shouldering bit may heat up and break. Or cause a weird looking finished edge at the least.
Maybe try a 65-025 (1/4") or a 65-021(3/16"), with oil/water mix mister. With that said, on my machine I cut 1/4" sheet aluminum, 2 passes, x-y=30ipm, z=3ipm, rpm=18000
Just keep in mind it's slow going.
My attached is of letters I just cut. 4'x8' 1/4" aluminum and it was just over 7 hrs.
Attachments
astro8
New Member
Good advice...only thing I'd add is you may want to add a cleanup pass as by the time you've cut through this lot your tool will have worn a little and you may get a slightly stepped edge. All depends on the finish required of course. So leave a couple of mm depth for a .2mm clean up pass (just enough so the tool will cut and not rub and set it for climb) or change to a new tool for the last pass if you want a perfect edge.
You can add a little detergent to the oil/water mix as well to keep your mister from gumming up. You can just clamp the sheet to the table for the initial cuts( 3/4" aluminium sheet isn't going to lift). If you have a vacuum bed, turn it on for the final cut as it'll help with any vibration and also if you have a vacuum (dust extractor) fitted to the spindle, let it ride on top of the aluminium to stop lifting on the final cut through.
Check your toolpath as well and make sure you've optimised start points (manually if needed) so the tool won't get jammed on the exit points. I find most tools are broken on the last pass as the tool gets jammed between the now cut out letter and the substrate. Don't under estimate this...I've had a 8" high 20mm thick acrylic letter fly out of the router and break the glass door of a microwave oven in the lunch room 30 feet away.
Send the job to a waterjet shop and get superior results in a fraction of the time.... CNC routers are great for lots of things.... cutting metal isn't one of them.
The 6mm 8x4ft sheet is a perfect example. On a router these letters take 7 HOURS to cut and require a lot of fiddling about using messy lubricants and expensive tools. With a water jet the exact same job in the exact same material would take less than one seventh of the time.... a realistic time is about 40 minutes from start to finish. The cutting process is much kinder on the metal and it's a straight through process... no passes required just punch through in one hit.
Cutting 3/4" aluminium on a router is never going to be an economical option and you'll struggle to even get close to the quality water jet cutting can give you as standard.
The 6mm 8x4ft sheet is a perfect example. On a router these letters take 7 HOURS to cut and require a lot of fiddling about using messy lubricants and expensive tools. With a water jet the exact same job in the exact same material would take less than one seventh of the time.... a realistic time is about 40 minutes from start to finish. The cutting process is much kinder on the metal and it's a straight through process... no passes required just punch through in one hit.
Cutting 3/4" aluminium on a router is never going to be an economical option and you'll struggle to even get close to the quality water jet cutting can give you as standard.
theskipman_98
New Member
I have to agree with those ppl that say to outsource to a plasma or waterjet company. My project being 1/3 of the thickness took over 7 hrs. I asked that ours be outsourced or find something with Gemini, but I am just an employee. I guess my labor is cheap LOL!
ASTRO: wanted to ask more about the detergent in the mister...
And as ANDY says the waterjet has a VERY nice finished edge. It doesn't heat the metal and cause distortions like the router does. When we go to attach some of the letters to an aluminum backer, sometimes (esp on bigger letters) you can see the warping in the letters.
Hope this is helpful, and to the others thanks for the advise
ASTRO: wanted to ask more about the detergent in the mister...
And as ANDY says the waterjet has a VERY nice finished edge. It doesn't heat the metal and cause distortions like the router does. When we go to attach some of the letters to an aluminum backer, sometimes (esp on bigger letters) you can see the warping in the letters.
Hope this is helpful, and to the others thanks for the advise
The Sign Dude
New Member
+1 for Plasma cutter
I did a job a few years back using .75 aluminum. everybody I talk to with a router didnt want to cut it. The reasons range from too much wear on their machine or was afraid of messing the sheets of aluminum up. We wound up having it cut on a plasma cutter in 2 pieces and having it welded together.
I did a job a few years back using .75 aluminum. everybody I talk to with a router didnt want to cut it. The reasons range from too much wear on their machine or was afraid of messing the sheets of aluminum up. We wound up having it cut on a plasma cutter in 2 pieces and having it welded together.
If you can't send this job to water jet however, go 18000 rpm with slow but not too slow feed rate. I would cut this in 3 or 4 passes 18k RPM and start with slow feed rate. Adjust on fly and cut whatever you need.
After you are done with this project you will understand why people sugested water jet cutting.
Once upon the time I had to cut 3/4" alu ribs on our SF multicam and had n problems. Would I cut 3/4" alu. on router ? sure when I need prototype or something small.
and....... don't forget to check what aluminum you will be working with. (grade)
After you are done with this project you will understand why people sugested water jet cutting.
Once upon the time I had to cut 3/4" alu ribs on our SF multicam and had n problems. Would I cut 3/4" alu. on router ? sure when I need prototype or something small.
and....... don't forget to check what aluminum you will be working with. (grade)
gomex design inc.
New Member
thanks to everyone for the input... just finished cutting. i ran it @10000 RPM with 60 IPM @ 10% feed using 4 passes and with one mister flowing tri-cool @ full blast and my vacuum on. it took 40 minutes for a piece that was 14" x 30"
theskipman_98
New Member
wow... I need to start messing with my speeds some more then. Was this just a rectangle cut to this size or some sort of shaped piece?
gomex design inc.
New Member
i have pix for those interested. this was a base plate and my first time cutting 3/4" thick aluminum. total success, i think waterjet was not an option, i knew my machine would kick ass. and it did...