Back to back g code help

Hi, iv had my table running for a few years, however, I never managed to get my gcode patterns running back to back without me manually starting them, I have managed to get them running but between the files they seem to lose Home so the next pattern makes no sense, I’m running Octpi with playlist etc… on a cnc shield, I did try homing between each one, however it ruins the wiper pattern, is there any other alternatives or alternative software?





Someone was just looking for plans for a 900mm scara table. How big is yours?

This issue actually makes a lot of sense. Can you post the last few lines of a pattern and the first few lines of the next?

My guess is that the scara conversion is winding the shoulder and the elbow up a couple of hundred rotations and then the next pattern starts at zero. We need to send a G92 or G10 L20 to remove those rotations so it doesn’t try to unwind every time. But how do we do that… We need to somehow run the modulo on the position. I am sure you can do it manually. But we need it in the software to be less annoying.

I wonder why we haven’t thought of this yet. Maybe everyone is homing.

Another workaround is to put the wiper code in a layer before the pattern and just run them together in the same pattern.

Thank you for the reply, The table is 1100mm in all but the useable sand bed is 750mm,

all my patterns are direct from sandify with only the one addition of f10 for speed, I have previously tried g90 g0 x0 y0 which resulted in may be able to get 2 file back to back on playlist however it would then start just looping round the outside and then do a crazy pattern,

I’m not sure why between files it can’t remember where the original Home is? on my CNC I run Ugs software and once I have Homed I can run as many files as I like without it losing its original Home is this due to running octopi?

Just look at the end gcodes on the scripts, they will have x and y coordinates in the thousands. That is because it is spinning around the center over and over again.

You can put G92 at the end, but only if the last position is at home. If you end on the outside, you’d need to have it at that coordinate offset.

I was thinking If I finished all patterns on the outside,
Could I add the same bit of G code to each file to send it back 0 but along the perimeter so it doesn’t ruin the current pattern?