It's begun....

[JAZZCNC]

Chris,

Just gone back and looked at the first post in this thread and I see the basic frame but can you post pics of the finished machine.?
Reason I ask is that you mention single screw and from the pic I'm thinking you must just have it down one side and not central to the gantry.? If I'm correct then your wasting your time using any calculator has the machine is so compromised with this set up they will be massively off target. Esp in aluminium.!!

EDIT: scrap that request looked a bit further up and found it.!! . . . Give it up untill you have the other screw you've no chance.!! It will turn into another beast with 2 screws.!!!

Looking at the machine and it's stubby size and strength then with twin screws it will easily cut aluminium with 3 flute cutter at 2.5mm DOC and 1500mm/min or more.
My machine is much wider and I easily cut at these figures and just today using 8mm size of this cutter (E5711 series) http://www.cutweltools.co.uk/files/ww/SM%20A160.pdf I was playing with DOC and cutting at 5mm Doc @900mm/min 9-10k rpm full slot without any trouble what so ever. I will try even deeper with 45% step over when pocketing and the tool spec says ok upto 1.5 dia @700mm/min 8K rpm.

HSS or carbide is mainly down to strength and the fact Carbide tends to work better when loaded up and can handle much greater heat and forces. To be honest I find I get better finish from HSS in Alu and actually prefer to use them for jobs where don't want to apply finish pass. With Carbide I can hog away put always have to do a finish pass for an acceptable finish.!