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General Mach Discussion / Rotational speed
« on: August 17, 2010, 03:28:14 AM »
According to the manual, section 10.1.6, when a move involves at least one linear axis and a rotational axis, the feed rate for the rotational axis is computed using the "correction diameter" to convert a feed rate in linear units into an angular rate which will get roughly that feed rate at the indicated diameter. That's reasonable enough.
Then, though, the manual says "For rotation of one rotational axis with X, Y, and Z axes not moving, the feed rate means degrees per minute of the rotational axis.". So, every time the program calls for a pure rotational move, the feed rate is supposed to be drastically different than for coordinated moves. Which is usually not what you want, especially with programs that may just happen to generate a move that's a pure rotation.
I haven't tried this on the real mill (which has an older version of Mach 3) yet, but i've been running Mach 3 R3 042 040 (unregistered/demo) on a computer not connected to a machine tool to test the GCode,. The A "radius" is set to 2.0, the "Radius Correct" indicator is yellow, feedrate is 54, but the A axis never moves faster than about 1 degree/second, which is far too slow for the indicated linear feed rate.
Then, though, the manual says "For rotation of one rotational axis with X, Y, and Z axes not moving, the feed rate means degrees per minute of the rotational axis.". So, every time the program calls for a pure rotational move, the feed rate is supposed to be drastically different than for coordinated moves. Which is usually not what you want, especially with programs that may just happen to generate a move that's a pure rotation.
I haven't tried this on the real mill (which has an older version of Mach 3) yet, but i've been running Mach 3 R3 042 040 (unregistered/demo) on a computer not connected to a machine tool to test the GCode,. The A "radius" is set to 2.0, the "Radius Correct" indicator is yellow, feedrate is 54, but the A axis never moves faster than about 1 degree/second, which is far too slow for the indicated linear feed rate.