Milling Experiences

Here we collect our experiences with CNC milling or routing different materials. Please add more information if you try something new (whether it's a success or not)!

Wood & Engineered Woods

MDF

operation	mill	spindle speed	feedrate	pass depth	plunge rate	results	comments
2D contour	8 mm flat endmill, Z=2 (Sorotec UNI)	16000 rpm ("1" on DeWalt 611)	2000 mm/min	3 mm		excellent	black (Bauhaus) two roughing and one finishing pass tabs to hold down work piece
2D contour	8 mm flat endmill, Z=3 (cheap "VHM")	21000 rpm ("3-4" on DeWalt 611)	1000 mm/min	2 mm		terrible	Bauhaus loss of steps or drift along x-axis overheated mill, black, dull
pocket clearing	8 mm flat endmill, Z=2 (Sorotec UNI)	16000 rpm ("1" on DeWalt 611)	2000 mm/min	3 mm		excellent	black (Valchromat)
2D chamfer	8 mm chamfer mill, Z=4	16000 rpm ("1" on DeWalt 611)	2000 mm/min			excellent	black (Valchromat)
pocket operation	1 mm flat endmill	16000 rpm ("1" on DeWalt 611)	400 mm/min	2 mm		excellent	black (Bauhaus)
drilling holes, pocket	1/4 inch Kyocera 1620 - 2500.500 flat endmill, 2 flute	16000 rpm ("1" on DeWalt 611)	1000 mm/min	2.5 mm	333 mm/min

Plywood

Most kinds of plywood should work, but of course you only get out what you put in - Micha has had bad experiences with pine plywood as it is much too soft and likes to warp.

Plastics

Polycarbonate works better than acrylic glass.

Acrylic Glass

operation	mill	spindle speed	feedrate	pass depth	plunge rate	results	comments
pocket operation	3 mm flat endmill, 4 flute	17000 rpm ("1-2" on DeWalt 611)	660 mm/min	0.4 mm		quite good	bottom a little rough

Polycarbonate

operation	mill	spindle speed	feedrate	pass depth	plunge rate	results	comments
pocket operation & contur	3 mm flat endmill, 4 flute	17000 rpm ("1-2" on DeWalt 611)	900 mm/min	0.8 mm	660 mm/min	quite good

POM

Bits

tested with 2 and 3 fluted HSS endmills (4-6 mm, but no indication against any other diameters)

RPM, Speeds, etc.

WorkBee spindle on level 1 (16000 rpm; DeWalt 611)

• Schnittvorschub: 500mm/min +
• Einfahrvorschub: 500mm/min +
• Ausfahrvorschub: 500mm/min +
• Helixvorschub: 200mm/min +
• Eintauchvorschub: 30mm/min
• Depths: 2-3mm

Strongly advise a horizontal Rohteilaufmaß and a final finishing cut to remove any "layer" marks.

Cooling

Not neccessary with the current settings but might increase the cutting speeds drastically

Metals

Aluminum

Possible on the WorkBee with a lot of patience and the correct bits, but check if it's millable aluminum

• different alloys of aluminum containing Cu, Si, Pb

Bits

• maximum two cutting sides
• carbide is more rigid than HSS and advised by some online guides
• tested 4 mm 2-sided pointy-end bit with acceptable success

RPM, Speeds, etc.

Values are only the tested ones, faster CAN be possible as well

• slow rpm: 16 000 is the WorkBee's default minimum but e.g. for a 4 mm bit, 6000 rpm would be better
  • different spindle or PID-ing?
• Feed Rate/Schnittvorschub: ~200 mm/min
• Einfahrvorschub: 15-20 mm/min
• Ausfahrvorschub: 200 mm/min
• Helixvorschub: 15-25 mm/min
• Eintauchvorschub: 15 mm/min
• Depths: 0.25mm per pass

Milling directions (to be tested): Conventional/Up-Cut (Gleichlauf) milling milling for the basic different passes with a finish using Climb-milling/Down-Cut milling (= Gegenlauf)

Cooling

Not yet tested

• any sort of lubricant or coolant will increase the efficiency of aluminum milling
  • there are suggestions ranging from cutting fluid over WD-40 to candle wax for lubing
  • as coolant, a water or alcohol mist is incompatible with the WorkBee's MDF spoilboard
    • instead, using the air compressor might be a possiblity