[landslide1]

I have searched on this issue but it seems G90 (abs) and G91(inc) are so self explanatory there isn't much info on them.

either mode has the same effect for me.

I zero the machine manually.
then move the table to about the middle.
g90 G00 X200.00 y-150.00

all the co-ordinate systems (absolute, relative and machine) move to x200.00 y-150.00

then if I enter G90 x20.00 y-20.00

the table moves to X220.00 and y-170.00

I was under the impression that in absolute mode x20.00 y-20.00 is 20mm both x and y from the absolute zero.

if I use G91 the machine behaves the same. incremental positioning from the last location.

what am I doing wrong?

[holbieone]

try just x20.00 y-20.00 or G00 x20.00 y-20.00 or G01 x20.00 y-20.00 F10.10

[landslide1]

^ tested those.
moves incremental from the x200 y-150.

G90 is modal and is on the screen. the machine starts up with g90 as the default.

[guhl]

if it occures in MDI mode you should set ABS to 1 on 1-st page of settings

[landslide1]

thanks guhl! that was it. simple fix.

[landslide1]

this came back to haunt me today.

I thought I had both G90 and G91 working by setting ABS=1. I thought I tested it after the change and had both G90 and G91 working.

however to day when performing a G28 z0.0, after first changing to G91, the machine it plunged down to the z0 before going to the reference point.

so I tested G90 x30. and it went to x30. then G91 x-20. expecting X10. and I got an over travel as it went to ABS x-20.

it is now behaving like it only has ABS.

anything I can try?