Originally Posted by
HimyKabibble
RPM should be calculated based on SFPM, which is typically 80-100 for HSS tools in mild steel, and 2-3X that for carbide tools:
RPM = 4 * SFPM / ToolDiameter(in inches)
In this case, you should've been running about 120-180 RPM, so you were OK with your initial setting.
Feedrate is based on RPM, chipload per tooth, and number of teeth:
Feedrate(in IPM) = RPM * #Teeth * Chipload
Chipload should really be gotten from the tool manufacturer, but if in doubt, figure 0.001-0.002"/tooth for all but small cutters (under 1/8" or so). So, if your saw had, say, 32 teeth, you'd want to run about 5 IPM.
Depth of cut can be set to whatever you can get away with, limited by spindle power, machine rigidity, and cooling. G too deep, and the spindle will slow down, and/or surface finish will deteriorate, and/or the tool will start to heat up. If any of these happen, back off on depth, or feedrate. But, it's best to find a feedrate that works well, then set depth to what the machine will tolerate.
So, overall, your RPM was probably OK, feedrate perhaps a bit high, and depth of cut probably low, unless you were running with no, or inadequate, coolant. Coolant is critical for something like this.
Regards,
Ray L.