Hardest aluminum long mill can CNC

Hi all,

I’m looking to make some things out of aluminum and wanted to know what’s the hardest I could mill? Can I work in 7075?

Thanks in advance.

Hey Sky, welcome back.

If you have a choice, use 6061. 7075 is harder, and therefore harder to machine. I have done a fair amount of 6061 machining on the LongMIll but I have not tried 7075. With a carbide 1-flute end mill I think you could do 7075, but the slower feed rates may be an issue. Remember that machines of this size are not rigid or powerful enough to push very hard. I’ve been doing depths of cut of about 0.010 - 0.015" with step overs of 10 - 20% and feed rates of 18 - 24 in/min depending on the toolpath. I think you would need to start at 50% of these numbers and increase - or decrease - with trials.

Please let us know how it works if you try.

Have fun. Stay safe.

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Bill, thanks for sharing your settings and speeds and feeds for aluminum, that is really helpful. I want to give this a try once I find some pieces to machine. Hopefully thinngs will calm down soon and I can get over to the metal supermarket.

I’m also planning on cutting some 7075 so would be interested to know what others have experienced with feeds and speeds.