Hi! A newbie question: I have a all-screw driven Ooznest Workbee 1015 with 1050w Kress spindle, and I've been cutting thick birch plywood using following parameters: - 8mm spiral 3 flute end mill (straight 2 flute waiting for testing) - feeds limited to 1000mm/min - depth of cut 2 -2.5mm - RPM 25k (all out) I have a feeling that the machine could do better (faster) but don't know where to start - faster feeds, deeper cuts or both? When cutting something really hard like oak, what to change?
You should be able to increase your depth of cut to 4 mm (rule of thumb - doc = 1/2 bit diameter). I don't often run my Makita (actually a Chinese clone) above setting 1 =10Krpm. I'm fairly sure you could increase your feedrate to 2 or 2.5 K mm/min as well. Change one variable at a time and gradually increase until you hear/feel that the machine is beginning to struggle and then drop back to the last value that seemed comfortable. There is not actually much difference between plywood and hardwood - you have to set things for the hardest bit of any material - knots in the wood or glue between the layers. There is no definite formula that always works - you can even get variable properties in different areas of the same piece of wood. Alex.
I do 2500mm/min with a 2 flute straight flute 6.35mm endmill using the same parameters as Alex (DOC for wood and soft plastics = 1/2 endmill diameter). But, as Alex said experiment. I often will adjust the rpms on my Makita while it is cutting if it seems like it is either too fast or too slow judging by the sound.
Thanks for the answers! Using the parameters I listed I can occasionally hear the spindle RPM drop significantly when cutting with full bit width - is that caused by too high RPM and/or slow feed not letting the bit cut as it should? I must say the chips I make are more like dust, and I have managed to set the dust on fire once using a worn out end mill
Too many flutes for a High RPM spindle Which leads to incorrect chipload thus making dust Try one of these instead (; Up-Cut Single Flute Solid Carbide End Mill 1/4"
