Machining Aluminum with a CNC Router
Lubrication, holddown, RPMs and feed rate are the issues noted in this discussion. November 13, 2005
I need to nest some signage for a customer out of .080 aluminum and would like to know what types of bits others are using, what feedrates, and what RPMs. We do not have the ability to apply a mist lubricant to the cutter, so we will have to run dry.
Whenever I have a customer that has a special application, I send them to Greg or Joe at Courmatt International and my customers always rave about the expert advice and the quality products that Courmatt offers. Tooling is only half of the battle when dry cutting aluminum. You really need to make sure that the part is fixtured very well so that it does not have any vibration when it is being cut.
Cutting aluminum is not that hard. WD40 works great for a lubricant. Just spray on the tool. I usually put particleboard on my router table and fasten the aluminum to the sheet. This will protect your table from the WD40. Use 1/3 to 1/4 of the feed you would use on wood. Iíve cut up to 3/8 with multiple passes.
We (Courmatt) have a tool as small as .125 that can machine n-f products without lubrication. The feed speeds will depend on size of your parts.
We have cut .080 aluminum without any problems using a carbide upcut 1/4" bit. We ran a few sheets this way, but if you have volume, get a mister. When we cut, I think I was running 200 to 250 per minute. It worked much better than the slower feed rate. It was scary at first, but the results were there. WD is good stuff to use. We would spray the field with a mist before machining and then follow the tool with a little bit more. We ran out of WD with one sheet to go and used water in a spray bottle. It kept the tool cool, but we had to do a complete wipe down and re-lube the ways to be certain they did not rust. It wasn't ideal, but the job had to get done.