Help!! Machining Alum with a cnc router.

[duraflap]

I need help with machining alum with my cnc router.
Can you help me out?
Thanks in advance

[psychomill]

What kind of help do you need? Can you be a little more specific? What problems are you having?

[duraflap]

Hi there
I'm using a .250 spiral up bit with a spindle speed of 10K, the slowest speed on my Porta Cable 3 hp router.Cutting dry at about 40 ipm feed speed and multiple passes of .05 using kerosene brushed onto the work surface for a lube. This all works great on T6 alum but not on softer material. I've played with the feed speed and cutting depth with no improvement so far.
The problem is that the soft alum sticks to the bit and if I continue, will fuzz up the cut and pile the material up the sidewall instead of creating chips.
I realize the spindle speed and dry cutting are not prefered, do you have any options for me?
Thank you for your help
Dennis

[DareBee]

A 4 flute cutter should run closer to 80 IPM at that RPM (2 flute would be about right), but your biggest problem is coolant/lube. You really need to get a heavy dose of it on there. You could also try a TIALN coated cutter, might help keep the chips from welding.

[psychomill]

Coolant!!

Kerosene is not enough lubricity especially at your minimum RPM with that size cutter. May want to try a slower helix tool as well since you can't get slower on the rpm. The helix angle may pull the material too fast for your set up. Are you cutting an extrusion?

[duraflap]

Tomorrow I get to play with this problem again. I'll try these suggestinons and hopefully have a home run. Thanks to you all, I appreciate the helpful suggestions.
Dennis

[duraflap]

Just a different thought. Does anyone know of an electronic speed reducer that will work on the big Porta Cable router? Anyone know how to slow the router down?
Thanks

[JRoque]

Hello. I've had problems cutting aluminum with 4 flute endmills. TiAlN, 2 flutes @ 6000 RPM does the trick for me.

As for the Porter Cable speed control, there's nothing you can add externally to slow it down. If you really want to do that, and void the warranty in the process, you can remove the speed control on-board the router and wire it directly so you can use an external speed controller for universal motors. A few things to keep in mind: common speed controllers might exceed the power rating of the motor, at lower speeds you won't have full HP output, lower speeds will not operate the fan at the required rate and overheat the motor.

I also own a PC router which I used for about 2 months before giving up and making my own spindle with a DC motor. Life's good now or at least better than before.

JR

[Nono]

Anytime that I have cut aluminum there has been a high stream of coolant. Sounds like high RPMs means faster feed rate and less depth of cut but definatly more coolant. Sound fun whatever you are cutting

[duraflap]

Well, The T-6 x still cuts just fine and the 4043 still gums up the bit and makes a mess out of the work piece. So... JRogue, how did you go about building your spindle from a DC motor? Would you care to share your ingenuity with this dummy? I think it is a great idea!!
Dennis@duraflap.com

[duraflap]

By the way, thanks to all of you for your input, it is all helpful...many thanks
Dennis

[JRoque]

JRogue, how did you go about building your spindle from a DC motor?

With a little help from my friends. Actually, a lot of help. Until I can get all the details under my machine log, check this thread for the entire discussion.

Regards,
JR