On Tue, Nov 17, 2015, at 02:40 PM, Marius Liebenberg wrote:
> >One question: why not make the pipe chuck be a U axis, the torch > >carriage is X, and let the g-code programmer have complete control of > >what happens? Move pipe only, torch only, or both, under g-code > >control. > > > Not sure I understand how to use the U axis. I will be using the > sheetcam rotary plugin to do the gcode. I will have to look at the usage > of a U axis before I can decide on that. If you are using CAM it probably makes sense to skip the U axis. If you were writing your own G-code the U axis would give you more flexibility, but the CAM won't understand it anyway. Just divide the steps per mm for X in half, and send the X steps to both gantry and pipe chuck motors using HAL. Also send X direction to both motors, and invert one so they travel in opposite directions. Use HAL logic (in the base thread) to turn off steps to each motor when that motor hits its home switch (only while homing), and to send a composite home switch signal to LinuxCNC when both motors have hit their home switches. If you are generating step pulses in hardware (Mesa, Pico, or other) then things get a little more interesting. More like a servo system, still doable but the approach is a little different. -- John Kasunich [email protected] ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
