Cutting .090 al sheet

[dubliner]

I have to cut 10 ft sheets for a sign shop in town, Big arrow shapes with big letters inside and need to do it tomorrow, cant get my hands on an O flute in time, what else can I use, speeds & feeds on an Alpha PRS & spindle, thanks in advance

[mitch_prest]

what bits do you have.. in the past couple of days I have struggled with some 1/4 aluminum till I got a single flute upcut O.. then I finally got close to what I what I wanted..

m

[knight_toolworks]

you can just use a standard 2f. 8000 tp 10000 at 1 ips is fine.
your going to have problems keeping these flat on the table they will want to lift up.
you may want a downcut if you can.

[dubliner]

Thanks guys. I have a 9-15 vac, I have some Onsrud, 2 fl down twist. Steve, I have a few questions about the cut sequences, would you mind if I emailed you directly? TIA Neville

[knight_toolworks]

sure no problem. thin plastic is a pain. most of the time I end up gluing it down but they are small pieces.

[blackhawk]

If you have a metalworking supply near you, just goto them and buy an endmill made for aluminum. They should have a decent selection. If no supply stores are around, goto a local machine shop and see if they would sell you an endmill. Any machine shop would have to have a few endmills made for aluminum lying around.

[mikek]

Neville, call Aaron or Nancy at Stokes Sign and ask what they are using. I think Onsrud 1/4" O'Flute from a supplier in Kyle. His price is a lot less than Onsrud direct. They buy large qty at a time and have just finished a very large Rough Hollow order using mostly 1/4" aluminum.

[aaasigncom]

ALUMINUM sheet and plexiglas cut in the same way with the same tool - single edge 0 and the same settings. i don't like spiril bits in thin material. use a spray mister, i think a must for alum. i use pegboard type material on top of my spoilboard so i can cut through the material to keep from cutting on the tip which is where the heat is. either way you want chips that look like fingernail clippings. slow down and allow the tool cut and not bulldose your way through the material. melting means too fast. i use ramped entry 50 ipm 9000 rpm

[john_l]

Neville, How did the job work out? What bit, feed and speed did you end up using?

[geneb]

This is something I'm going to end up doing a lot of. I've tried all sorts of variations and I break a lot of bits.
What would you folks recommend for an 1/8" cutter in 6061-T6 sheet? I've been trying it with a four flute end mill at 6000rpm and a VERY VERY slow speed. I use a 16 divider to slow the bot down (VU<lots of commas>,16). While this works for the most part, the last job I ran took four hours to complete and the part wasn't very large. I also take tiny bites out of the material - typically about .015 per pass.

Thanks!

g.

[navigator7]

My guess is less flutes and a vary fast speed on the router.
Everything I've seen with that material is done at a high speed.
Machinists I've talked to say aluminum knows no limit.
You need to take a chip.
I can't give you a feed rate...to me it's sound and the flow of chips.
To my knowledge...slow is not good.
Cooling air is good.

6061 T-6 is heat treated I believe. This could explain the tiny bites.

[aaasigncom]

definitely not a 4 edge tool. tell us about your chips size. single edge 0 or see this amana tool http://www.toolstoday.com/p-5801-aluminum-spiral-o-flute-solid-carbide-router-bits.aspx

8108 - this shot is .080 alum cut in one pass

[blackhawk]

Gene - You need to use no more than a 2 flute cutter with 1/8" bit in aluminum. You definitely need an upcut. I would try your speed at 10,000 rpm. MSC has a 2 flute Cleveland endmill made specifically for Aluminum. HSS part # is 87420212, they also have TiN and TiCN coated ones.

[donchandler]

I used router bits for aluminum made by Micro 100. They work great. I cut .060 deep @ 1 ips and 15000 RPM.
8109

[eaglesplsh]

I just cut more aluminum yesterday - clean cuts with no coolant/compressed air necessary.

I cut both 6061 and 6063 (Ultra-Corrosion-Resistant Architectural Aluminum) using single upcut "aluminum" O-flute bits from Onsrud.

McMaster sells several sizes/lengths of Onsrud's bits. I try to use the shortest LOC possible to avoid chatter. Here's the part numbers for 1/8" and 1/4" short versions: 3317A21 and 3317A25

Yesterday I ran the 1/4" bit at 1/16" depth per cut and 1.5 ips feed. Porter Cable router was set for full speed - 21,000 rpm I believe.

Tony's remark above matches my experience - you get chips that look like fingernail clippings or silver confetti pieces 1/16 wide by 3/16 long.

[geneb]

Thanks for the advice guys. I'll be printing this thread for reference.


I may end up getting some of the Micro 100 cutters. The price is a bit easier on my limited budget.

tnx!

g.

[dubliner]

It worked out very well thanks to Aaron at Stokes Signs who gave me some bits as I couldnt get them when I needed them. Last night I cut 7 sheets of .090 3003, with Onsrud High Speed steel upcut/2 flute. 18k rpm. .8 in.x.5 Z.in one pass. These bits cost $4.85. All of the advice above is pertinent, but what I learned was that ZERO vibration/100% hold down is a key factor. Vibration will re-weld & snap the bit in 2 seconds. Chips are the thing, ( theyre hot too )BTW I was using 1/4 in last night but used 1/8 in for smaller letters. This was the first Al I have cut & it was very cool having only used wood to date. I think I will beef up my vac table & create a good pick up method ( chips everywhere )and cut metal more often. Thanks for all the tips from everybody.

[mitch_prest]

is it possible to change the name of this thread to read aluminum instead of just AL.. that way it will show up in future searches

Don ...what size was the bit used to cut the Ford insignia ..

[donchandler]

Mitch,
I used 3/16 bit on the FORD logo. The ribs were cut with a 1/4" bit

[geneb]

Neville, could you tell me the Onsrud P/N for the bit you used?

I've been using 3M77 to hold down material to an HDPE spoil board that's been clamped to the table.

I've used that method with both aluminum and acrylic and as far as zero vibration hold down, it worked great. I'm concerned about using an upshear cutter on it though. The last thing I need is for the material to be lifted...

g.

[eaglesplsh]

Gene,

McMaster also sells a straight flute version of the Onsrud O-flute bits for aluminum.