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View Full Version : Anyone tested milling soft aluminium with Joes CNC?



Viperia
05-29-2007, 08:22 PM
Hello,

Im planing to build Joes CNC router as a project in school after the summer break since i think it is one of the most detailed projects here on cnczone and fit´s my needs for doing some wood/plastic cnc things. But as the title read is there anyone that have tested machining soft aluminium with this cnc machine?

Could be cool to know if it has been done and if someone did get it to work so please inform me about this. ;)

Regards,
Viperia

trajan
05-30-2007, 05:52 PM
Viperia, I believe that the rotational speed of a router is much to fast for machining aluminum. I have a mill and machine aluminum at approximately 300 RPM. The recommended router (Hatachi) for Joes CNC router has variable speed of 8,000 to 24,000 RPM.

After I get my Joes router done I plan design a motor mount system for a DC motor I bought on eBay. I will buy a 90 Volt speed controller and try to machine aluminum. The collet mechanisum will be challenging.

Richard

Viperia
05-30-2007, 05:54 PM
Well i know the speed of the hitachi router is to fast but thought maybe someone has used another router on his build.

Regards,
Viperia

Smackre
06-02-2007, 09:15 AM
Milling alum is possable. I seen a guy do it on a machine like joe's first model. He used very small tools so that got the rpm up alot. I have a commercial machine and i run 8k rpm on a 3/8 tool for alum and it works pretty well. I also use compressed air to blow the chips out.

As for milling alum on a router. Id advise using a roughing end milling as much as possable. Roughers cut at prolly 20% the pressure of a finish tool. I cut alot of parts out with rougher only. And use coolant if possable or air to at least remove the chips. Hardest thing about milling alum is keeping the chips from gualing up the tool.

But I do not advise milling alum on a regular basis on a home built machine. I would think it would vibrate your machine to death.

Hope this helps you out.

ger21
06-02-2007, 09:45 AM
Viperia, I believe that the rotational speed of a router is much to fast for machining aluminum. I have a mill and machine aluminum at approximately 300 RPM. The recommended router (Hatachi) for Joes CNC router has variable speed of 8,000 to 24,000 RPM.


You can buy router bits for cutting aluminum at router speeds. www.onsrud.com

Smackre
06-02-2007, 12:58 PM
Those onsrud bits call for a 300-400 cutting speed right? I do not think thats possable on a home built machine. Running them slower might burn the bits up.

ger21
06-02-2007, 01:12 PM
Those onsrud bits call for a 300-400 cutting speed right?

Depending on the tool, they recommend chip loads from .002-.010.
A single flute tool with a chip load of .005, at 15,000 rpm = 75ipm feedrate. With an 8000 rpm router you can get down to about 40ipm.

Smackre
06-02-2007, 10:02 PM
where do you get recommended chip load for the onsrud bits? I am looking at there single flute o alum cutting tools but I dont see chip loads anywhere.

ger21
06-02-2007, 10:11 PM
In the back of their catalogs.

Or here:

https://www.onsrud.com/xdoc/ChipAluminum

Smackre
06-02-2007, 11:22 PM
Thanks for the info. Even with those tools I would think it would be tough to mill alum on a homemade machine. Even one as Good as Joe's. I would think you would need linear rails to mill alum.

Shev
06-15-2007, 11:14 AM
K2CNC has 3 videos of milling aluminum with a PC router...

http://www.k2cnc.com/Videos_CNC.asp

foam27
06-15-2007, 12:24 PM
Hitachi M12VC router, 24,000 RPM, 1/4" triple flute flat endmill, 80 IPM.

Trapaezodial belt driven X axis no less....

No problem...

joecnc2006
06-15-2007, 01:08 PM
Hitachi M12VC router, 24,000 RPM, 1/4" triple flute flat endmill, 80 IPM.

Trapaezodial belt driven X axis no less....

No problem...

Good info. on the Hitachi router. it seems to be a good cheap alternative to the PC for the hobbiest.

What was your depth per pass?

Thanks, Joe

foam27
06-15-2007, 07:00 PM
Joe,

I always seem to forget some tidbit of info that completes the equation :)

I believe my depth was around .01-.015 on that one.

silver4dracs
10-09-2007, 04:18 PM
I just ran Joe's machine at 35ipm 24000RPM at .01 per pass and no problem. Cut file took 2 hours to cut. I broke a bit running at .06 per pass and 15000 rpm, the bit completely gummed up and broke.

joecnc2006
10-09-2007, 04:33 PM
I just ran Joe's machine at 35ipm 24000RPM at .01 per pass and no problem. Cut file took 2 hours to cut. I broke a bit running at .06 per pass and 15000 rpm, the bit completely gummed up and broke.

Any picture of cut piece?

i take it that the material used or bit was the cause of bit breakage? I know cheap bits will break with ease.

maybe list material (grade) and bit used, and aplication.

Joe

darkfred
10-09-2007, 06:27 PM
The onsrud catalog includes formulas for setting machine speed and pass depth for each bit. The parameters given look to be well within the range of joe's machine and the hitachi router.
Soft aluminum may need some lubrication to avoid welding to the bit if it doesn't get ejected by the previous twist. Other forums have recommended an occasional spritz of wd-40.

However, I have been doing some research on this topic. I think the ideal metal for joes machine would be ZA-12. It can be cast at insanely low temperatures, melted in a bbq or a small box made of firebricks and filled with charcoal. It is much harder than AL and better suited for machine parts. It has good wear characteristics and does not need to be tempered. It is machine part hard when cast. And, it machines just as well as Aluminum.

So...
1. Cut a block in the shape of the machine piece you want to create. Make it 105% (guess) of the final size you want the piece to be.
2. Make a sand imprint of the piece. And cast it in ZA-12
3. Machine finish the piece using your cnc mill and an onsrud aluminum finishing bit.

Lost foam casting could even get you completely 3d parts. But you would need SolidCam or similar to setup the face finish machining. And a jig to hold the piece for each face milling. (or a 4 axis mill)

This is what I intend to try as soon as I my kit arrives. I have been playing around with the casting but need a mold making machine now :)

Regards,

silver4dracs
10-09-2007, 07:11 PM
http://www.cnczone.com/gallery/data/500/dynaudioaluminumring.jpg
The material was T6061 1/4" aluminum. I used a regular wood 3/16" 2 flute endmill, no coolant, no air, just a vacuum for chip ejection. Cut depth was .01 per pass. To cut two of these took almost 2 hours with hole drilling. Speed is really not an issue with me.

I broke the bit being much to aggressive with the cut depth. At first, I set it to .06 per pass while slowing the router to nearly the minimum speed setting and the bit gauled up and broke.

joecnc2006
10-09-2007, 10:12 PM
nice looking mount.

technomage
10-10-2007, 07:19 PM
I have seen quite a few posts about cutting metals and certain plastics with wood router spindles. I got to thinking that what might be useful would be a very tiny torque converter like on a car except scaled down. Being a small fry I have no desire to create one from scratch so I went looking and found this
http://hi-tech-pr.com/goped/goped-liquimatic.htm
Its used on motorized skateboards. I was wondering if something like this might work to convert the 8000 rpms of a wood router spindle done to something more in line with machining aluminum.
Hope this is the right forum if not let me know and I will repost.sorry double post
Hope to hear what everybody thinks.
Technomage

mdframe
10-10-2007, 09:35 PM
nice looking mount.

Joe,

I hate to seek you down like this but I am not getting responses from you via e-mail so I can only assume your SPAM is catching me. I need to discuss the kit I purchased and awaiting delivery. Please contact me as soon as possible.

Thanks,

Matt

joecnc2006
10-10-2007, 10:10 PM
Joe,

I hate to seek you down like this but I am not getting responses from you via e-mail so I can only assume your SPAM is catching me. I need to discuss the kit I purchased and awaiting delivery. Please contact me as soon as possible.

Thanks,

Matt


Got your message on here and just responded.

Joe