[msimpson99]

I had a project where I needed to cut slots in some 1" square aluminum tubing. The problem was its the cheap 3003 kind.

[ame=http://www.youtube.com/watch?v=Wui9MEO11Ug]KRMx02 Cutting Aluminum Booms - YouTube[/ame]




Details

My first attempt failed as it gummed up the bit.


I had some bit cleaner/ lubricant on hand and gave it a try.


Success.


Finished booms.


See my complete writeup here:
Cutting Aluminum Booms

[fizzissist]

3003 isn't "cheap" aluminum, it's just a particular alloy.....

Next time, try WD40. One of the few things it's good for is machining aluminum!

[BAMCNC.COM]

WD-40 sprayed while machining, not just before.

[msimpson99]

I would have tried WD40, but did not have any on hand. The stuff I used is defiantly more environmentally friendly, and cleans up well with water. It’s a little pricy though.

I call 3003 the cheap stuff cause thats what all the department stores use. I did find some 6061 tubing at Tracktor supply but it was at twice the price.

Dont need to spray while machining. The way I did it worked just fine. Need just enough to keep the aluminum from sticking to the bit. Not using it as a coolent.

[DonFrambach]

Thanks for the tips. Please keep making these kind of posts and videos! They are much appreciated!!!!!

[ssutton]

I cut aluminum all the time on my machine, soft alloys and harder alloys. In my experience blowing the chips out of the cut path is essential to successful aluminum machining. I find that it is more important than lubricant because the aluminum cannot melt on the tool if it is not allowed to recirculate around the bit. I use an attachment made into my dust collector hood that directs compressed air at the cutting tip. This solution has totally changed the way my machine cuts aluminum. Having said all that, any alloy that cuts dry will almost always cut better with lubricant, I have just found that with the proper tools air evacuation is MORE important than lubricant.

Scott

[louieatienza]

I found that with softer alloys, it helps to use a bit or endmill with a lower helix angle, or even a straight o-flute bit. This allows the chip to form and break off instead of stringing up. With the harder alloys the higher helix angles give more cutting edge engagement and smoother finishes.

It just so happens Onsrud makes a low-helix o-flute and extrusion cutter, specifically for softer alloys. Having coated bits and endmills can help with softer alloys.

[BAMCNC.COM]

A ZrN coated endmill doesn't need any lubrication for Aluminum, I would use air blast though.

[msimpson99]

What is the Onsrud Part number for the soft alloys cutter?

I was using a 63-610 which works very well on 6061.

[msimpson99]

I will also try using air. What CFM are you directing at the cutpath. I did not have my dust shoe connected as I wanted to record the process. However with the dust shoe in place I would be willing to blow the chips as they should be contained.

Since I got into making multi-rotor aircraft, I have been using more and more of the softer aluminum. In the past I just used my drill press to drill the holes. Now that I am into weight reduction I suspect I will be doing more milling.

I have a second 18"x14" KRMx02 CNC in the shop that is collecting dust. I was thinking of setting it up for this type of task. Ie removing all the wood fences/clamps, adding a blower and possibly a mister.

Any recomendations?

[louieatienza]

Low helix 1-flute slow-spiral aluminum cutters (ZrN coated)
63-420, 3/16", 63-430, 1/4". Onsrud recommends 13,250rpm at 100ipm.

Estrusion cutters
81-103, 5/16", 82-104, 3/8" (1/2" shank.)

Aside from preventing galling, using at least some lubricant (even on coated tools) extends tool life and provides a superior finish.

[ssutton]

I have no real solid data as to the CFM, it must be high, my compressor cycles about every 5-6 minutes when running and my compressor is a 90 CFM machine. I am using a needle valve and directing the blast at the tool with a small copper tube that is pinched at the tip to a fine point. My 2HP dust collector overcomes the added air volume under the hood and it still extracts the chips. I would follow all of louieatienza's recommendations as to tools to use, he has machined more aluminum with his machine than most of us here including me.

[ssutton]

Whats up with my reference to my dust collector having a hyperlink to a dust collector? I did not create the link?????????



Now the link has disappeared.........very strange

[ger21]

Go to the User CP, then Options, and disable Skimlinks at the bottom of the page.

Also, I think you guys mean PSI, not CFM.

[ssutton]

Thanks, killed the option, must be set on by default.

I think that the question was Cubic Feet per Minute, psi on my compressor is set at 125 cycle off and 90 psi back on.

[ger21]

Do you really have a 90CFM compressor??

[ssutton]

Well, I will have to check, not is the shop??????????????

[ssutton]

5.8 SCFM @ 90 PSI. Just a slight error certainly within the margin of error for this forum. But really we degress.

[msimpson99]

This project page has been moved. You can see it here:
Aluminum Booms — Kronos Robotics