Cutting Aluminum

[GlenP]

Hey everyone. I have had several requests in the past to cut aluminum on my PRS standard and have always turned it down. Now I have a customer that I cut wood and acrylics for needing me to take on their aluminum parts. I have a fellow botter that has done metal with the proper bit and cooling fluid misting on the bit. If I did it this way I would need a tray to catch coolant and not make mess of cnc bed. Anybody cut 1/4" or 1/2" aluminum?
Hope your all busy.

Glen:)

[dlcw]

Glenn, cutting aluminum has been touched on several times on this forum. If you do a search I think you will find lots and lots of really good info.

[dana_swift]

Glen- when I cut Al, I just put compressed air directly on the bit. It blows away the chips and helps cool the bit. No fluids at all.

Keep the cuts very shallow and much smaller chiploads.

Its worked for me, I have cut Al, Copper, Brass, etc..

D

[GlenP]

Thanks Dana. What type of bit did you use? I have seen some solid carbide ones on different sites.
I am going to get some aluminum from the customers as they will be supplying their own. The company I am going to be doing this for is one of the largest Canadian suppliers to municipalities so there will be lots of cutting. I have been looking into plasma cnc machines but I would like to have the bot do it if it can.
Love to have a dedicated machine for metal but shop and budget doesn't allow it.....yet ;)

[dana_swift]

Here is a snippet of a video of how I have done it:

http://www.youtube.com/watch?v=CzigLEGIFkM

That was an early effort (very successful). Since then I have used pretty much the same method, with better air blowing on the bit.

In this case I used a 1/8" end mill. I have also used 1/4.

D

[dhunt]

Here is a snippet of a video of how I have done it:

http://www.youtube.com/watch?v=CzigLEGIFkM

Interesting!

Didn't someone in here speak about misting with alcohol while cutting?
Alcohol cools like crazy ..while evaporating away ;)
.

[araugh]

Here is a snippet of a video of how I have done it:

http://www.youtube.com/watch?v=CzigLEGIFkM

That was an early effort (very successful). Since then I have used pretty much the same method, with better air blowing on the bit.

In this case I used a 1/8" end mill. I have also used 1/4.

D

What bit are you using here? Thanks!

[GlenP]

I just order couple Onsrud bits # 63-622 which are a o flute end mill. They recommend misting or fluid to make last longer but I am going to try Dana's suggestion of air and see how it goes. Thanks for the help. If this works for me it will open some new doors and opportunities. :)

[kg4mon]

I cut aluminum all the time with by bot. I use a onsrud o flute 1/4. I move at 1.25-1.5 ips and .015-.020 deep per pass. No fluid at all. Just air.

[donek]

I cut aluminum all the time with by bot. I use a onsrud o flute 1/4. I move at 1.25-1.5 ips and .015-.020 deep per pass. No fluid at all. Just air.

Just ran 250 1in X 2in X1/2 parts over the weekend with this bit:
http://www1.mscdirect.com/cgi/NNSRIT2?PMAKA=71177190&PMPXNO=20571202&cm_re=ItemDetail-_-ResultListing-_-SearchResults
no air or coolant and the bit is still working fine. I actually sharpen these bits all the time on my grinder. A single flute bit is very easy to regrind the bottom surface/cut down. Machine time was 24mins per 8 parts, so a total of 12.5hrs. I use a PC router at 1800rpm. Typical feed speed is 1.2in per second on finish cuts and 2in per second on roughing cuts. Pass depth of 0.050in. If you don't need/want sharp corners at the bottom of your profiles, slightly rounding over the point of the cutter will produce a better surfacing finish.

https://lh6.googleusercontent.com/-dPEZkGjwa6E/UEkVIcC8ZBI/AAAAAAAAAMk/5VtZekrbAUE/s1059/0906121525.jpg

[feinddj]

I use a Vortex air cooler when I cut in al or acryllic. It takes compressed air and drops the temp by about 35 degrees farenheit. I use a rigid tubing to blow the air right on the bit under the dust skirt. It works very well.

David

[GlenP]

Does anybody have more info on these vortex air coolers? I did a goggle search and get allot of info on enclosure cooling or fog machines etc??? :)

[Brady Watson]

Just to be clear...you don't need ANY coolant (air or liquid) to cut AL. Tooling geometry is the most important. Cooling will certainly help - but it isn't required.

Before you go out and plunk several hundred dollars on a Vortex - and if you believe you need coolant in order to feel good about cutting - then go to Depot & buy a Husky blowgun with football inflator kit (all in one pack). Then get a couple 90 deg elbows and an 8" nipple and a few 3/4" close nipples that fit the football inflator adapter tube. Then mount it to your spindle shooting at the bit. 25psi is plenty. Tape over the safety hole...Get creative - you'll have $30 into it max.

-B

[donek]

Just to be clear...you don't need ANY coolant (air or liquid) to cut AL. Tooling geometry is the most important. Cooling will certainly help - but it isn't required.

Before you go out and plunk several hundred dollars on a Vortex - and if you believe you need coolant in order to feel good about cutting - then go to Depot & buy a Husky blowgun with football inflator kit (all in one pack). Then get a couple 90 deg elbows and an 8" nipple and a few 3/4" close nipples that fit the football inflator adapter tube. Then mount it to your spindle shooting at the bit. 25psi is plenty. Tape over the safety hole...Get creative - you'll have $30 into it max.

-B
As Brady said, cooling really isn't necessary. The primary goal is to avoid cuting a chip a second time. If you need a small amount of air to remove the chips, then Brady's tool will work as will a piece of copper tubing connected to an air line. The cutters designed for cutting AL with a router expect cut dry. Just get your chip load right and everything will be fine.

[mryan]

I have not cut aluminum myself yet but have being investigating this option. In my research I came on this device which looks worth trying.
http://www.arizonavortex.com/spot-cooling/
Cheers
Mryan

[rustnrot]

Sean, just to be clear I think you meant your Porter Cable router cut this at 18,000 rpm?

[donek]

Sean, just to be clear I think you meant your Porter Cable router cut this at 18,000 rpm?

Did I say something else?

[Pete M]

The Bot can do almost anything, including cutting aluminum(god's favorite metal), but cutting aluminum is not its strong point. Glen's original idea of declining aluminum cutting was not a bad choice. The best results cutting aluminum on a bot are really not all that good, compared to real metal cutting CNCs. My Bot is a hobby for me, but I earn my living with CNC machines, cutting everything from plastics to hasteloy, and aluminum cuts like butter. Rigidity, speed, and coolant make the difference. There are reasons why some machines cost hundreds of thousands. The small Tee nuts,(i presume), that Sean made certainly look functional, and the cycle time seems reasonable, but the chatter would be a deal breaker where I work. I don't mean to be rude, but...right in the scrap barrel.

[twelchPTM]

the scrap barrel is my favorite place in the shop. "dat der is beer muny"

[donek]

The Bot can do almost anything, including cutting aluminum(god's favorite metal), but cutting aluminum is not its strong point. Glen's original idea of declining aluminum cutting was not a bad choice. The best results cutting aluminum on a bot are really not all that good, compared to real metal cutting CNCs. My Bot is a hobby for me, but I earn my living with CNC machines, cutting everything from plastics to hasteloy, and aluminum cuts like butter. Rigidity, speed, and coolant make the difference. There are reasons why some machines cost hundreds of thousands. The small Tee nuts,(i presume), that Sean made certainly look functional, and the cycle time seems reasonable, but the chatter would be a deal breaker where I work. I don't mean to be rude, but...right in the scrap barrel.

Thanks Peter. I agree the finish is not as good as the Drag Knife parts we outsource. These parts are burried inside the device they go in and the machined surfaces will only be seen by the customer that disassembles the device.