A customer and EMC user in Brazil has asked about something I have thought about a couple times. What he wants is a lathe with a C axis for programmable positioning. So, sometimes he wants to spin the spindle at some speed for normal lathe work, and sometimes he wants to position the axis.
As far as commands, one could envision that the axis is a speed spindle when an M03 or M04 command is given, and when M05 is given it turns into a C axis, and will turn to the position specified in a C word. Now, I think I actually know how to do this in HAL right now, but I'd have to go through E-stop to make the switch-over without causing a following error or servo amp trip. Obviously, the user would want to have this all done smoothly without having to go into E-stop. When in spindle mode, you'd want to prevent the PID calculations from seeing the C axis position changing. That could be done by switching where the encoder info is routed through hal pretty easily. It might be possible to give a long delay after shutting the spindle off, and having some hal components gradually ramping up the servo gain so that the spindle will be smoothly brought to the last commanded C position. You probably need to throw in a spindle sync operation so that the spindle won't be made to unwind 10,000 revolutions to get the count back to zero. Any thoughts on this? I could see using some of my servo amps to drive small spindle motors for both spindle and positioning modes. Jon ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ _______________________________________________ Emc-developers mailing list Emc-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-developers
