milling aluminium without coolant ?

[andy55]

Hi all,

I've got access to a nice Isel router which I've fitted a 700 W 10-30krpm spindle on. I'd like to do some work in aluminium with 4 mm or 6 mm end mills taking maximum 3 mm deep cuts. The router can do at least 5000 mm/min feeds if neccesary.

I'm wondering if there is a combination of feed/rpm/endmill material etc. with which this could be done without coolant ?
I'm asking because the router is and will be situated in an office space so I can't really mess about with fluids etc.
pressurized air and a vacuum cleaner close to the endmill would be ok.

thanks for any answers,

AW

[ClockedOUT]

i have a large isel router. I usually cut acrylics and wood, aluminum sometimes.

Maybe you could try a high pressure "air blasting" coolant hose/nozzle.

I guess its an alternative to liquids. Otherwise at such high speeds, its pretty hard to keep the cutters cool, especially that small.

good luck

[kong]

What about micro-drop lube? No mess, just a nice smell!
http://www.tricomfg.com/store/Produc...D=31&ProdSeg=4

[Xterrian]

I've been cutting home cast aluminum (pop cans mixed with intake manifold) with a 4mm end mill. I've cut up to 25mm per minute at about 15,000 rpm (half the max speed of the rotozip) with no coolant and no problems. I'm currently cutting a box with thin walls inside that are only half a milimeter thick. I make sure to vacuum the chips after each pass and am taking a single milimeter off at a time at 21mm per minute with no chatter, no galling and no coolant. I tried using WD-40 when I first started cutting aluminum, but found the cuts weren't as sharp and smooth or quick. I just make sure to keep the mill loaded so that the chips are big enough and leave often enough to take the heat away with them. I recommend lots of experimentation with scraps.

[Xerxes]

Isopropanol (alcohol) works great with aluminium. At least it doesn't leave any mess behind but air must be ventilated.

[mxtras]

I don't have one of these machines so I can not speak from exact experience.

I don't think heat is the problem with the smaller tools - it's getting the flutes cleared to prevent clogging (as stated by Xterrian). I finally resolved an issue I was having on a coolant-less machine with a directed blast of air and backing off on the chip load. I recorded the exact conditions but I do not have that in front of me right now. I seem to recall running a 1/4" two flute tool, 1/8" deep in 5000 series aluminum at 12,500 RPM and a feedrate of 8 or 9 Inches per minute (230mm/min) with the air jets pointed to evacuate the chips. This is shooting from memory but the numbers sound reasonable. But this was on a different machine - a commercial router. Does this help at all?

There is a thread on this site that has a listing of good speeds and feeds for routing aluminum. I can not locate it at the moment but it is here - it was done maybe 2 months ago. It's good information. Dig around a bit.

Pay attention to your chips. You want them to be substantial enough to take the heat with them but not large enough to clog up the flute or to be difficult to extract. If your tools clog, slow something down and keep the flutes cleared out.

Scott

[Switcher]

Good luck with the chips, in a office!