I'm going to be hogging out some fairly large lumps of aluminium over the next few days on my Sieg X1. I obviously want this to be as quick as possible without risking anything - I really don't want to waste these 'big' lumps of aluminium or the gears on my mill.
What size endmill, feedrate and depth of cut is very effective at removing large quantites of metal on these machines? What has worked well for all the other X1 owners out there?
My spindle is standard, so 2000 RPM is the speed limit - which I really should change (but not right now).
I have been doing a few things on my CNC'd Super X1. This is totally experimental. Right now I've made the plates for the belt spindle conversion. Using a 1/4" end mill, this included 2" circles, 5" radius arcs, peck drilling using a 5/16" drill bit through 1/4" aluminum. I'm using 4 flute mills because that is what I have. I think I need 2 flute. The only coolant was aluminum cutting fluid dripped on which gumbed up around the endmill. Will probably dig out a coolant sprayer I have but it uses compressed air and I hate to listen to it run. Feedrates and steprates have been:
1/8" endmill: .05 step and 6in/minute 2000 RPM milling a pocket, not full passes due to wizard programming. I think it cut 30% of the endmill width. On a full pass today while cutting a 5" long arc broke the endmill, went to a 1/4".
1/4" endmill: .02 step and 4in/minute at 2000 RPM milling the circles and arcs. Full pass.
I think I tried .05 step early on but was nervous. Aluminum bits went everywhere. With the coolant and proper endmill this could work fine. Probably somewhere in between .02 and .05 would be good.
5/16" endmill: .01 step and 4in/minute at slower than 2000 RPM milling a short arc pocket. This was slow and I didn't want to mess something up.
5/16" drilling. .025 step, Mach3 wizard, very fast. Precision drilling is cool.
I like this machine it amazes me what it will do. Jim