I'm looking to mill a 1" x 1/4" slot through the middle of some 80/20 1010 extrusion. I'm a noob with CNC. Would it be best to drill 1/4" holes on the ends of the slot and then mill out the middle or just mill it all out? I was thinking that drilling first would help with chip evacuation. I don't mind the ends having the 1/4" diameter. I just need a way to run some wires from the front channel to the back channel.
I've got 1/8" and 1/4" Onsrud single flute "O" style upcut bits at my disposal.
Just mill it all and use some WD-40 or similar for lube.