Recently someone approached me with a good reason to try and start to mill either Cooper or Brass. Is it reasonable to assume I could do this?
If I can mill those metals, where could I find more information on feeds and speed for Brass other than g code wizard & CNCZone?
Both should be a bit easier than Aluminum, start with those numbers and vary the depth of cut. The biggest priority is getting the chips out so you do not re-cut them and double your chip load, so an air blast helps.
I imagine the air assist I use for the laser should be strong enough to blow the chips out of the way. I also read the brass need a flatter cutting helix than aluminium does but they didn’t specify an angle. Do you know if should just look for endmills that say they can do brass or would it be better to find out the angle of the helix for brass since I might be purchasing at least my practice endmills from China? Once I tune everything in I plan on getting higher quality endmills from somewhere else.
I suggest using a single flute, I have some in the shop. There are lots of things to try but depending on your build they will all be different numbers than anyone else. Don’t over complicate it, it should not actually be that bad, sheet material needs to be stuck down or use a down cutting bit the rest a single flute should be fine, adjust the RPM, depth, and feedrate. I am not sure about your air assist. I can cut aluminum without any air, but you can cut faster with it. If you can cut wood and plastic you will be fine.
Stop ASAP if your bit gets metal stuck on it and adjust your settings, that will break your bit.
You have to be careful with reading some of the suggestions out there. Most are for giant machines where every second of machine time is extremely valuable. We are in a different class. You can go by the recommended chip loads for a bit but always stay at the lowest end of that figure.
Will the chip load vary per the material or is that typically universal for the bit?
Also do you know the recommended chip load for your end mills?
And without accurate RPM readings that is extremely variable.
Have a look through some of my youtube videos and have a look at the ultra conservative numbers I use, that should get you started.