First attempt in aluminum

[DarinB]

I had a project at work and thought, "I can do that!" It took me 2 bits, but I finally got the feeds & speeds down. I used an Oflute 1/8" @ 50IPM, 13k. My first bit went to going too fast on ramping. I slowed it down to 5ipm plunge rate and it went like butter. Very smooth and easy the second time. The pattern looks odd, but it is for an IR laser that will mount up to an IR thermal camera. I made it to be adjustable in elevation and windage so no shimming would be needed.

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[elcar903]

Nice,

I use 4 flute end mills with AlTiN coating on them and I like to put some WD-40 on it while its running to help the aluminum from sticking to end mill
and because I don't have coolant I use air cooling from my air hose to keep it cool which seems to work for aluminum.

[DarinB]

You run a 4 flute on a Shopbot? I've always thought that it was too much for a regular cnc to handle. Most of the posts in here suggested running a single flute at slow feed rates. I know the industrial grade machines run the 4 flutes and up, but I've never tried it on mine. What feeds & speeds do you run with it?

[elcar903]

here are the settings I use on my SB Buddy, also I do have the spindle not router head so it does handle it better,

if it chatters try slowing RPM or feed down, keep plunge rate low as well and keep air cool on it for long jobs, plus the WD-40 helps too.
other than that I have no issues using it.

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A vacuum plate I made for with my SB out of aluminum.

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[DarinB]

The only thing that showed up was the pic of the vacuum plate. Very nice btw. I'll have to try that next.

[elcar903]

hmm not sure why they didn't show up but I'll re post them.

RPM is based on machine and feed rate so adjust it as needed

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[DarinB]

Interesting speeds. I've never ran my spindle lower than around 10k rpm. I'll have to try these numbers next time. What kind of parts do you cut on the vacuum plate?

I found a good page on this : http://credentiality2.blogspot.com/2009/06/shopbot-aluminum-feeds-speeds.html

[elcar903]

I do engraving and plastic parts with the vacuum plate mainly

[RossMosh]

With a router there are two ways people recommend cutting aluminum.

1. Fast and multiple passes. You might run at 100+ipm but only take .02"-.05" per pass.

2. Slow and deep. You need a machine with some horsepower to do it, but with a high HP spindle (5hp+), coolant/lubrication, and air you can make some pretty heavy passes. .125" no problem in one pass with 3/16" cutter.

You'll absolutely find pocketing is way easier than cutting. When cutting you need to keep the kerf and area around the cut very clean. It's very easy for aluminum to weld itself on to the bit. If this happens, you will snap a bit. A blast of air is very effective along with a spray every once in a while with WD40