Strange Problem- Never seen before

[khalid]

Hi,
Today i was calibrating my Y-axis slide... After calibration i started Mach3...Put G00 Y12 in MDI command line... The motor moved to exact 12mm.... But when I put in MDI G00 Y0.. The motor didn't moved.. When I entered G00 Y-12 motor moved to G00 Y0 (ie original position)... Why this happen?
Any thig wrong in settings?

[ger21]

You're in Incremental mode instead of Absolute. Try G90

[khalid]

Hi Gerry.. You are right, To run G02 and G03 moves i set the IJ mode to incremental but the Distance mode is Absolute... If i do not change IJ mode to Incremental i get the error in Mach3 for trochoidal tool paths...

[DaveCVI]

I don't think it's the IJ incremental/absolute mode that is the issue.

A mismatch between GCode assumption and the IJ incr/abs setting can cause the "wrong way loops" that people see. The default IJ mode is controlled by the General config settings. The IJ mode can also be switched within a gcode program by G90.1 (IJ abs) and G91.1 (IJ incr).

Whether coordinates, and hence movement, is incremental or absolute is independent of the IJ setting. 

Absolute coordinate mode is set by G90 and incremental coordinate mode is set by G91.

Dave

[khalid]

Its working now...
G90 G01 Y12

I don't know why this problem happen..I never put G90 before...

[Hood]

Its working now...
G90 G01 Y12

I don't know why this problem happen..I never put G90 before...

Possibly some previous code had a G91 in it and it never got changed back to G90.
Hood