milling aluminium

Harm,

Brave to start with the most difficult material.
Aluminium has many different types Alloys so if you want to mill try to get some of the NEN 5000 or 6000 series.
If you get your aluminium from the hardware store it is mostly soft alu of the 1000 series, this is very hard to mill.

But regardless what you use make sure to take the following in account:
- slow speed of the mill (8.000 - 12.000 rpm)
- slow to medium feed (100 - 150 mm/min)
- don't go deeper than 0.2 till 0.4 mm per turn to be save for the first time go 0.1 per turn
- use a 2 flute millbit for Alu
- good clearance of chips (airblower or brush)
- good cooling (spirit or cooling liquid) apply by airbrush or pipet
- be alert of nasty sounds, hand at emergency stop

Be gentle and you will succeed

Hi,
I did quite a lot of testing with 6000 aluminium on a Stepcraft 600/2 with a Stoneycnc Industrial quality small HF spindle.
Here are some of my results.
I found higher spindle rpm with a single flute bit worked better.
pd = pass depth
ss = spindle speed
fr = feed rate
pr = plunge rate.

pd 0.2 mm
ss 15000 rpm
fr 10 mm/sec
pr 3 mm/sec
very low vibration, clean cut, oil

pd 0.4 mm
ss 18000 rpm
fr 5 mm/sec
pr 3 mm/sec
very low vibration, clean cut, oil

pd 0.4 mm
ss 18000 rpm
fr 5 mm/sec
pr 3 mm/sec
very low vibration, clean cut, washing-up liquid

pd 0.5 mm
ss 18000 rpm
fr 5 mm/sec
pr 3 mm/sec
very low vibration, clean cut, washing-up liquid

pd 0.7 mm
ss 18000 rpm
fr 4 mm/sec
pr 3 mm/sec
low vibration, clean cut, oil

pd 1 mm
ss 18000 rpm
fr 3 mm/sec
pr 2 mm/sec
low vibration, clean cut, oil

pd 1 mm
ss 20000 rpm
fr 3.5 mm/sec
pr 2 mm/sec
very low vibration, clean cut, washing-up liquid

pd 1 mm
ss 20000 rpm
fr 3.5 mm/sec
pr 3 mm/sec
low vibration, clean cut, no lube

I haven’t listed all my results but hopefully these should give you some idea.

Thank all for the input i'm going to try it and let you know what the result is like.