View Full Version : Milling aluminium advice needed

04-11-2017, 10:21 AM
Hello gents.
I've googled it and searched it and there's a lot of info I just don't understand about it.

I'm looking for simple advice, not links to tables or previous threads, as I know this has been asked before.

What is the best cutter, mill speed and feed rate to mill 10mm aluminium?

I've tried alsorts!
I have a 3040 cnc
I'm using a 4mm end mill.

I've tried 2,3 and 4 flute
16000, 20000 and 25000rpm on my Kress 1050w
200mm per minute and sped this up and slowed it down
I'm cutting .7mm per plunge and and still clogging and snapping bits like there's no tomorrow

Any advice greatly appreciated

Thank you

04-11-2017, 10:51 AM
Hi John,

I have found that single flute carbide cutters work better for ali. They need to be 'open architecture' to allow the chips to fly and you need air to shift the cuttings away.

I am experimenting with stiffening up my wibbly wobbly MD machine and the initial tests are good, both in terms of finish and also cutter breaking seems to less (I chewed into my first test at a far higher feed rate than ever before and the cutter did not immediately snap).

I have my Kress at full speed for most jobs.



04-11-2017, 11:19 AM
thanks Rob.
i had to stiffen the wobbles too. :smile:
i should have mentioned too that i'm dry cutting but shifting the chips with a hoover and a little spray of wd40 every now and then.

04-11-2017, 11:37 AM
You would find it better cutting if you moved onto the 6010 plus alloy much more forgiving on cutter, the 3010 plus is gummy to cut and you will brake more cutters as you have found.
single flute cutter are the best to use but 2 flute with a little wd spray will work just fine.


04-11-2017, 11:57 AM
thank you for the reply Phill.
it is 6010 aluminium i'm using, the 3040 is the machine i have ( a chinese desktop cnc)

could you advise:
a feed rate?
a spindle speed?
a cutter? answer seems to be single or 2 flute
plunge per pass?

04-11-2017, 12:04 PM
i'm making motorcycle thum brakes and sometimes they come out with no issues, then i go to do another with the same cutter, same speeds, same aluminium and have nothing but problems


04-11-2017, 12:36 PM

This is the blower nozzle on my machine, I use a Hailea 80L/min pond aerator pump and it shifts the chips away very well. When I have tested the new stiffened Z axis and dust extractor, I hope to make a post of it. My experience and the collective wisdom of the forum is that these little gantry machines really are not up to the job of cutting aluminium and giving consistent good results.

Perhaps you should do a finishing pass to reduce the 'chewed :black_eyed:' look.

04-11-2017, 01:16 PM
Single flute cutter, ramped profile path, optional finish pass, WD lube, air to shift chips, vacuum will not do it well enough to prevent chips being circulated and re-cut.
Single flute cutters have the massive advantage of being easy to sharpen by hand, with just a little practice,

- Nick

08-11-2017, 01:18 PM
Things I have sussed.

Kress at full power, 25000rpm
320mm/m feed
2 flute Alu Power 4mm cutter
1mm depth per pass
A mixture of lemon juice, old engine oil and water squirted into the path makes an excellent cooling/lube
Gantry cnc's are awesome

I've had zero snaps and cut 4 brakes out with the same cutter.

Hopefully someone will read this and find it useful.