Setting up to use an AMANA V bit to engrave acrylic. Amana recommends 18K RPM and 90"IPM (or 2286mm/m) for this bit. Depth of cut is .2mm. Lead screw is a 4mm so by my calculation I should only need around 600 RPM from the NEMA's. Drivers are 542's set to 2.37A to avoid excess heating of the motors. GRBL max feed for the X and Y axis is set to 2500mm/m, max acceleration is 50mm/sec, squared. Using the "continuous" button in Candle to move the X and Y axis, all is well. Home the unit, send an actual program, and it stalls, lower the feed rate to 1500 and it works. Way too slow for acrylic, it just melts. Should I crank up the amps on the motors, they are rated at 3 amps, and live with the heat?? Any suggestions much appreciated. Motors are running on 24V.
Higher voltage will get you more speed, current is torque (basically). Can't slow down your spindle? I've cut plenty of cast acrylic with no issue and never get close to 2000mm/min and that's with cheap 1/8" bits. Extruded acrylic is another story! BUT screws at 600RPM might whip Also with acceleration set to 25mm/sec you will probably never hit those speeds engraving text. Cheers Gary
Thanks for responding. When cutting acrylic we ran an Amana 51411K "O" flute at 450mm/m and 12K RPM and it does a good job. We tried Amana's recommended 2200mm/m and 18K RPM and it does leave a much smoother edge. I tend to think that bit manufacturers know more about their product than I do. This is for a 30deg V bit. Any thing slower than what Amana recommended and it just melts and sticks to the tip. We also were concerned about the lead screws so upgraded to 10mm plus the span is only 400mm. Quick plug for Amana's tech folks, very quick to respond. Thanks again.
