Ray Henry wrote: > Hi Andy > > I don't remember the details of your machine but if it's servo with > encoders you might look at the location of the index pulse with respect > to the angular position where the home switch closes or opens. In the > old days we called this stuff a grid and if the switch closure was right > close to the index it could jump a full rotation, or in the case of a > resolver 1/4 of a rotation. IMO it's a good idea to put the index pulse > a half rotation away from the switch change. What you are describing is a non-repeatability in the home position. The index pulse should have no effect except during a homing operation. What Andy seemed to describe was a sudden shift in machine position vs. the displayed coordinates. Of course, anything is possible, and software or hardware bugs could cause the encoder counter to reset on an index pulse when it was not supposed to. Normally, in a closed-loop-to-the-PC servo system, this would cause a following error, at the least.
Jon ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2005. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
