Hi,

I recently finished my CNC mill/router, I use a Industrial Bosch Grinder as a spindle that has 300W and spin at 26krpm ( With no load of course )

Im milling 6531 aluminium ( Its what we get here its almost like 6061 that you guys get there )

Well I just dont know what cut speeds I use, I'm new to this milling thing and dont understand the cutting speeds at all, all the speed calculators I tried to calculate I didnt see any consideration about the depth step of the cut or the the side step of the endmill. I dunno the name for that i think its something like side movement % and vertical movement per pass... I think thoose calculators most of them consider a Industrial standard or some machine with a 10hp spindle, they dont know my spindle isnt strong enough to take 3mm deep each time

My step motors are strong so they dont loose steps even when I overload the machine with some set up that i cant run, basicaly the part jams the endmil on place but steppers keep runing and carry everything away, or break the endmill = (

Im using carbide end mill, most of them uncoated, I have ran tests on the speeds to see how fast i can go but it doesnt make sense like sometimes i get better finish with faster speeds, and somethimes dont, I can go like 80imp or 2000mm/min and cut just a little like 0,02depth / 0.6mm that it kinda cuts good and it barely heats the part, but when i start cutting things 1200mm/min ( 48ipm ) with deeper cuts like 1mm deep it doesnt cuts that good and it heats more... I tried lots of variations and sometimes a 1mm deep cut at 2000mm/min cuts better then a 1.5 deep with 1000mm/min ( all tests i just put some singer oil on the part and on the endmill, i tried dry too it tricks me anyways, finish using oil is way better of course )

Yesterday i cut 2 round pockets same set ups 1/4''endmill same depths and all, but one 1200mm/min and the other 700mm/min same amount of oil, the 1200mm had better finish and looked better ..... When i get a good result and i slow the speed most of the times i get a even better result with slow speeds, but not always

I think its something to do with the fact that the 300w spindle is not strong enough, but the biggest endmill i use is a 1/4''

Anyone have some tips or what set up I shoud use?
I mean i could just run ultra slow or ultrathin depths, but i wanted to make the parts as fast as my machine can, slowing about 30% after finding out how fast that is, of course just to avoid any surprises...

Sorry for the huge post
Thanks for anyone who hepls