"Pete C." wrote in message
ster.com...

Ignoramus5687 wrote:

I have decided to dial way down this time. Again, I am making a mold
cavity in aluminum for making a kids wax toy (toy railroad supports).

This time I am using 1200 RPM and 1 IPM, and in addition I use WD-40.

The good news is that nothing gums up, the bad news is that the speed
is ridiculously slow. Yes, it is CNC, but still.

Next thing on my list is getting coolant to work. I have a
professional coolant tank with motor etc and also a little 1/70 HP
pump that works great in plastic buckets. I think that I will use the
latter Then I can go at the same 1200 RPM but at much higher feeds.

i

Iggy, it *aluminum*, aluminum is routinely machined dry. Coolant isn't
your problem, but it's getting you wrapped around the axle and not
focused on where your problem actually is. I machine quite a bit of
aluminum and pretty much never use any sort of coolant, or even sprays
of WD-40. The only time I use fluids on aluminum is when hand tapping.

agree with the above - with the last piece of aluminum I machined on my
Abene mill, I needed a 1/2 inch by 3/4 inch deep rabbet around the edges of
a slab - I put in a 1 inch end mill at whatever my table of RPM said for
aluminum and milled it in a single pass, I think I had the feed set to 4
inches per minute, but it's been a while - worked perfectly. of course this
is a manual mill, not CNC, but that shouldn't matter