Cutting 0125 Aluminum on Dimension 200

[heymatthew]

Hello all,
I'm new to the Gerber Routers and am using a Dimension 200 with T-Vac, etc. I'm trying to cut some 0125 Aluminum and I keep snapping bits.

I'm using the Gerber lubricant through the compressor system with the small black nozzle/hose aimed directly at the bit to keep it well oiled. There's a very fine mist coming out, which I'm assuming is correct. If this sounds incorrect, please let me know if I'm doing something wrong.

Is there anything that I can do differently to keep from snapping bits?

My settings are as follows:
Bit: 3/16 Belin Aluminum Bit
Total Depth: .125
Depth Per Pass: .042
Total Passes: 3
Feed Rate: 20
RPM: 18000

Any help would be greatly appreciated. I've had great luck with PVC, Extira, Acrylic, etc. The aluminum is snapping bits 30 seconds in (or less) every time. I think my boss is going to start taking them out of my checks.

Regards,
Matthew Morse
TheSignChef.com
Charleston, SC
843.345.0186

 

[daveb]

What's your feed rate, we cut .125 on our Sabre in one pass with a 25-30 feed rate.

 

[heymatthew]

What's your feed rate, we cut .125 on our Sabre in one pass with a 25-30 feed rate.

My feed rate is 20 with the RPMs at 18000. Too slow I'm guessing?

 

[daveb]

You can bump up the rpm if you want to but I don't think that's your problem. The only thing I can think of is the aluminum is too soft. I you didn't tell your supplier you were going to rout it they could have sold you 5051 or something that wasn't meant for routing. You need 2024 or some similar alloy. Is there burrs all around the edges where you're cutting? Does the aluminum come out of the bit in chips or goobers? If you're using a good mist coolant and a carbide bit you shouldn't be having a problem unless you've got the wrong aluminum. Check with your supplier and see what you got.

 

[John L]

Is there burrs all around the edges where you're cutting? Does the aluminum come out of the bit in chips or goobers?

Dave are you saying that these are signs of an improper alloy for routing? I ask because I have had those issues a time or two with aluminum .125" and ticker but always managed to dial it out with feed and speed changes to get nice little smile chips before the bit broke. But I'm thinking maybe I was trying to rout 5051 or something.

 

[daveb]

Low mist coolant can cause similar issues but from his description his mist coolant was working properly. I've been out of the router room so long I can't remember all the numbers but the harder the alloy the better for routing, you can actually see the difference... the good stuff will have an almost mirrored finish to it (shiny anyway). The better the aluminum the bigger the chips will be if your feed rate is right. I never will forget... I had a sheet of 1/4'' on the table cutting letters out and about halfway through the router started bogging down, there was a spot in the middle of the sheet about 10'' around that was softer than the rest of it, the aluminum hadn't been mixed properly before it was rolled. The right aluminum is fun to rout... the wrong stuff and it's a pain in the butt.

 

[Tony Teveris]

Check out the FastFact on the Gerber web site #5049.

If you can not find or get to it send me your email and I'll email the PDF

 

[J Hill Designs]

also make sure you are held down very well - chatter and cutting aluminum dont really mix

 

[heymatthew]

Thanks for the responses guys. I'll try all of those things. I've just put an order in for a handful of the Belin bits. I'll keep you posted.

 

[synergy_jim]

my guess would be too soft of an alloy also.... I ran a job with 5051 once and it wasn't pretty....

 

[epatsellis]

been a while since I've run a router, but I tend to prefer more rather than less coolant. 5XXX aluminums can be easily cut with a single O flute bit with .001" to .002" chipload, with proper cooling and lubricant. (not just coolant) chipload is critical, as the chips carry the heat away, too thin and you'll build too much heat in the sheet.

Is the metal building up on the bit as it cuts? (you may have to look at the broken part to see it), if so, you need more/better coolant/lubricant and to increase your chipload, too slow can be worse than too fast, especially with aluminum.

My feeds and speeds probably won't have much relevence to you, as we typically ran at around 35K with 40 to 70 i.p.m. feed rates with a water cooled high speed spindle single pass with lots of coolant/lube, not just a light mist. Many coolants only cool by evaporation, with softer aluminum, you want a lubricant as well. I can see if I still have my notes from when we had our router if it will help.

 

[Tony Teveris]

Although the basic set-up should do the trick, is the aluminum you are trying to rout tempered?
Is it a good grade aluminum?
If it's a "3000" series aluminum with no heat treat (temper) it will give all kinds of problems.
This type of soft aluminum will easily melt to the flute of the cutter even with the coolant flowing. Turns the bit into a butter knife.

A good grade to use would be a "5052 - T6" - the T6 being the heat treat (temper) rating.

 

[epatsellis]

Tony, I'm curious what the reccomendation for 3XXX series aluminum would be. My experience was that you needed a rather aggresive chipload (3 to 5 thou is a starting point), sharp (as in brand new) single flute cutters, a micromister with lubricant and a very aggressive feed rate (as well as a spindle capable of those chiploads and feerates). I found a huge difference between the common cutting coolants and lubricants, though the lubricants cost more, the cut quality improved so drastically that secondary processing became unneccesary and the labor savings were greater than the price differential.

I had a heavily modified Cybermation 8x12 and the high speed spindle was great for some things, but cutting 3003 requires such a heavy chipload that you really needed more than a 2 hp spindle. I do have clients with 5-7.5 hp Perske and Colombo spindles that have no problem routing it however.