Hey guys!
I just finish converting my proxxon mf70 to cnc (usb and grbl). And I have question about milling, how you set feed rate, deep of cuts and spindle rpm ? I tried different setting for milling in aluminium, but Iam not happy with end results.
I use end mills from 1mm to 3mm, best results so far I get with feed rate 200mm/min, 20000rpm, and 0.2mm deep + WD40 as coolant. But I think it is to slow. What is yours settings for milling in aluminium and other materials ?
Cheers!
Hi, thats quite an arrangement you have made there. Great job - Congrats.
I’ll be interested in replies here too, since I have a MaxNC10 whih is about the same size and have just been cutting Acryl so far. But i’m afraid my motors are too weak.
What motors, torque and Amps have you got installed and what is the power of your spindle ?
I have 3x 2.4A and 0.8Nm steppers, powered from 35V power-supply and driver. Spindle is stock proxxon mf70 spindel, and it has 100W of power and max. 20000 rpm. I mill aluminium with no problem, just want to tweak cutting speed and quality of cutting edges.
This steppers are enough, or maybe event little to big for this machine. I decrease it torque to 50% on driver, because I was afraid about leading screw in the machine.
Waiting for some practical advises from more experienced guys here, on how to set up milling parameters correctly 
Quick calculation, and this calculator give me 1260mm/min in PVC with endmill dia 3mm and 5k rpm - i think it is impossible 
You’re right about acrylic milling. Keep spindle speed as low as possible. I did it at less than 1000 rpm for a 3mm tool. That is without cooling.
For better cutters you get a data sheet with recommended and maximum values.
Otherwise there are tables and calculators to get good values depending on cutter geometry, depth of cut, material, cutter material and abilities of the machine.
I highly recommend using them as it makes a ton of a difference to doing this by ear alone.
The problem is that for example, I have cheap 3mm tool made with VHM, and that all information that I have. For home/hobby use, better cuters, with provided datasheets etc are too expensive. So, I’m looking for some common knowledge about using this cheap cuters.
I also have random cheap cutters and tools, with absolutely no data on them.
So - I use my common sense for this.