Points Covers Easy Y Shifting

[saxman]

IMAGE - http://shadowsoft-games.com/saxman/pntcover.jpg


I am unable to figure out why my G-code doesn't do what I thought it was supposed to. What I have done is create 3 different points covers. I originally created them in their own seperate programs. I want to cut out all 3 on a single sheet instead of having to switch between sheets each time.

In the uploaded picture, you see these covers and how they are supposed to line-up. Each cover is 4 inches apart both X and Y. Problem is, because I drew all 3 seperate, their origin's are at X0 Y0. I figured with G-code, I could correct the problem. This was my plan:

- First draw the '1' covers as normal based on X0 Y0.
- G92 Y4 ; This should move the '1' covers up +4.
- Draw the '2' covers based on X0 Y0.
- G92 Y4 ; This should move the '1' and '2' covers up +4.
- Draw the '3' covers based on X0 Y0.
- G92 Y-8 ; This moves everything down 8 so that the '1' covers are at Y0, '2' covers are at Y-4, and the '3' covers are at Y-8.

When I graph this, it shows up exactly how I expected it to. However, when I go to cut out my parts, when it gets to '2', it still thinks that Y0 is in the same position as '1'.... so it wants to draw '2' on top of '1'. I am not understanding why the machine is doing something different from what my graph shows. If this method that I'm using isn't going to work, is there a better method instead of manually changing every Y position? One method that is out of the question is changing the Y home position.


If it helps, I'm using Centroid's Intercon v8.22. I am programming the information into ICN files (which allow you to manually enter G and M codes if you wish).

[DAB_Design]

Any chance you could post the actual g code?

[HuFlungDung]

G92 is tricky to use...not difficult, just tricky

G92 does not cause any motion of the machine.

G92 renames the coordinates of the current position. That means you should cut the first one, beginning at X0 Y0 then make a move (by your calculations, I guess) to the beginning point (origin) on the second profile. When the machine is there, then you program that position as G92 X0 Y0. Then, rerun the rest of the profile just as it was the first time. Then, move to the origin of the third profile, rename it G92 X0 Y0 and then cut it.

A better way is to use work offsets, G54 through G59 are commonly available. This is because your position at the end of the last profile is still stuck in the frame of reference of the last G92 coordinate system. By contrast, using work offsets, you can "get out" of any offset coordinate system by cancelling it with G53 (which returns you back to the machine coordinate system, which is G53 by default).

When you are all done cutting however many widgets, you may not know exactly where the machine position is any more, because you have called the G92 many times and don't know the coordinates of the home position. Thus, you may be able to move back to the very start (home) position on your control by commanding a move to G53 G00 X0Y0, which should take you back to the machine's home position. Be careful when trying this out for the first time! Make sure your tools are all clear (preferably not even in the spindle!) and turn down the rapid speed to observe the motions in slo-mo.