1/4" End Mill with Aluminum

[haley]

Does anyone have any suggestions on router setting, feed and speed for milling Aluminum (6061). Attempted 12000 RPM with feedrate around 500 mm/min and the end mill started to gum up slightly. 

[Hommer Woods]

Try the calculator on the Millright site.


www.millrightcnc.info/#calc

[Derek the Admin]

How many flutes on that end mill? Be sure to avoid a 4 flute with aluminum. I think you need to pick up the feed rate some.

[haley]

2 flute 1/4" end mill, cut depth around .3mm

[Derek the Admin]

If the end mill is sharp I'm surprised its gumming really. Are you certain that it is 6061?

I would still pick up the feed rate, but that should be a piece of cake without any gumming with your current settings.

[ttabbal]

Aluminum can be a pain. If you can keep the cutter lubricated it will help. WD40 works decently, a koolmist setup works well too. A good budget setup would be to have a compressed air flow over the cutter with some WD40 on the metal. Coated cutters will also help. Another option is roughing endmills and use a normal version for a finish pass.

What grade of aluminum? 6061-T6 is ok, 7075 can be nice as well. There's a guy that sells "Fortal" brand drops on ebay in a hobby box that has been good material to work with. The random stuff at the big box stores should probably be avoided.

Also make sure you're using a nice sharp tool. Dull tools will get built up edge faster.

Speeds and feeds are critical on metals. Check into that as well. Knowing which machine you are using would help as well, the various machines have different rigidity. What works on a Power Route might well have trouble on an M3.

This is all based on manual milling, I don't have my CNC in had yet, expecting Monday.

[freik]

When milling aluminum, I used the feedrate calculator (here) set to 8000 RPM with the aggression set to 'conservative' to keep bits from breaking, and then kept dousing it with Tapmatic Natural cutting fluid (less smelly than WD40, and not toxic, unlike most other cutting fluid I could find). Putting a ring of hot glue around the cutting area helps keep the mess at "minor catastrophe" levels, as opposed to "Superfund site" without it. (Seriously: cleaning up aluminum shavings *sucks*!)

I've carved 6 aluminum keyplates, as well as a nice depth detector block. Without cutting fluid, the bits tend to break and dull much more quickly.

-Kev

[jamesterm]

Nov 15, 2018 20:31:34 GMT haley said:

Does anyone have any suggestions on router setting, feed and speed for milling Aluminum (6061). Attempted 12000 RPM with feedrate around 500 mm/min and the end mill started to gum up slightly. 

I have been using M3 on 5052 aluminum... Derek is right about the feed rate. Look for my post back to the Curivator project as I have details and video on what works for M3. I'm on the road on a phone right now otherwise I'd post a link. I also have details on drilling holes too. It's in the project talk. The solution I use requires no lube or coolant. The main thing I can tell you is to take a leap of faith on these settings... if you do what I did and go slower because it sounds louder... it starts a vicious circle that leads to gumming the bits. Finally I use a tabbing strategy that relieves the bits chip load and heat... as a way to forgive if my settings are not quite spot on.