Hi,
I cut aluminum with a 3.25 hp router at work and with a 2.25 hp router at home. I use a water and oil mist coolant at work, but it's messy so I went with a Lenox Micronizer Jr. oil mist coolant system for home that works just as well. It blows compressed air at the bit, and adds 3 to 6 drops of cutting oil per minute to the air.
I use a 1/4" 2 flute up-spiral endmill TiN coated carbide router bit whenever possible, and 1/8" when I need sharper corners. I have heard of people using a 1/16" or smaller bit with aluminum, but I haven't had any luck with those bits.
The speeds and feeds I use are 10-15 ipm depending on the edge finish I need, 16,000 rpm for 1/4" bit and 19,000 rpm for 1/8" bit.
I cut up to the diameter of the bit per pass, and between 50 and 75% step-over for surfacing, again depending on the finish I need.
I use 6061-T6 whenever possible, increase the feedrate for utility grade to avoid melting and plugging up the bit.
Steve |