When I was thinking of the R7 cutting aluminum was very low on my priority list but I have found a use for some. What cutter is recommended for 1/4" plate?
An upcut endmill
Smw3d have some good upcut single flute 4mm bits which work well. I have also found 2 flute 1/8" bits work well. I am cutting a lot of aluminum right now with some great 1/4" 2 flute diamond viper black coated bits which are awesome but send chips flying across the garage almost hot enough to burn. It’s quite the experience.
I would recommend starting with "1/8 2 flute end mill. Start slow, until you get the feel of it. Shallow passes to start. Start with a slow plunge rate. You feel find any loose part/ weak point in your set up, the keep kicking up the speeds as you feel comfortable