Re: DIFFERENCE BETWEEN G90 & G91?

I got 2 cents!

G91 is like giving driving directions:
From here, go 3 blocks south, turn left and go 4 blocks to the east.
Turn right and go 1 more block south.
All the moves are measured incrementally from the last point. The
pain with this and machining is you have to start and stop at the
same point. Kind of like going around the neighbor hood and ending up
exactly where you started from. If you don't do this right then as
you repeat the run, you also stack the error. Say you went around the
neighborhood and you came back to the same point as you started but
you missed it by 1 foot. Then do it again, now you are off 2 foot,
then 3. Get the picture?

G90 is like plotting points on a graph. All the points are measured
from the exact same reference point and you can start and stop from
any one point. The machine always remembers where your reference
point is at so there is no getting lost. From an industry point of
view, 99% of all my programming has been in G90 absolute. Most
machines "wake" up in G90 mode.

Happy Toolpaths!

--- In CAD_CAM_EDM_DRO@y..., "woodknack" <wjdupont@h...> wrote:
> What is the difference between G90 which is absolute mode and G91
> which is incremental mode. Can someone break down what absolute
mode
> and incremental mode is. Its probably very simple, Im just very new
> to this.