Tractor always driving to the left of line (but not AB line)


We set up AgOpenGPS on our little Kubota tractor last spring and seeded with it. It drove nice and straight but I had 1 issue with it. (We used V2.0 pcb with CMPS14)

The tractor would track centered when going back over the set AB Line, but when following any line that wasn’t the AB line the tractor would drive to the roughly 5 or 6 inches to the left of where AgOpenGPS thought it should. The lines were always nice and straight but to the left of where it should have been.

I know it was tracking centered over every AB line because I set marker flags at each AB point and verified that the tractor would drive properly back over each line.

I learned to work around this issue by always setting the AB line in the center of the plot and planting in a counter clockwise loop. I could, by trial and error first, find a value for tool width that would give me just the right spacing.

I remember reading a post buried deep in the forum a couple years ago that this issue maybe something related to the WAS but I’m sure the WAS was setup and working properly. But, I can’t find that post now.

We haven’t setup AgOpenGPS on the tractor yet this spring as it is at the mechanics getting fixed but I’m anticipating running into this issue again. Does this sound familiar to anyone?

The only thing I can think of looking back is maybe it was something to do with the tilt, but again im sure i had it zeroed properly and it was reading ok. Well maybe I’ll try setting antenna height to zero and see if that does anything.

Thanks for reading.

Like an ab curve? Or an A+ line?

any machine offsets set in agopen?
is antenna absolute central or an offset set up to set it right?
loose lower link stabilisers allowing machine to drift?

Not quite clear on what is off. You saying AOG says it’s on line, but tractor is driving 5-6" off? What is distance to line on AOG, 0? What happens when you shift AB?

So, the original ab line acts normal no matter what direction you drive?

Do you have pictures, or illustration of what it’s doing? I will say, I had to get away from cmps and switch to BNO085. My issue was heading East would be erratic.