Change calibration grid offset to be a percentage?

Spot on, I agree.

No, this bounding box has no bearing on later cutting operations. It is ONLY used during calibration to set the size of the calibration grid.

I completely agree. I don’t think that we want to be running the calibration at the absolute limits of the sheet. That’s asking for trouble with something getting caught somewhere.

I concur 100%. In fact we CANT even define the work-piece location before calibration because until we have accurate measurements for the anchor point locations all of our measurements are not accurate. If we wanted to say “The top left corner of the work area is HERE” the here that we’re talking about is in relation to the anchor points. Once we run calibration and get better values for those anchor points our “here” will have moved and we would need to do it again.

That, in my mind is the key. The decision about how big to make the calibration bounding box ideally should be informed by a measurement uncertainty analysis (MUA) that determines how much better the calibration is when the bounding box is made bigger. Without that, the next best thing would be to try calibrations at different bounding box sizes and compare the calibration scores. At least I think that would work.

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Unfortunately the calibration score actually gets better with worse input information. Three points close together in the center of the sheet will always give a great score because the more similar the input information the easier it is to find an answer that fits all the points.

different bounding box sizes, and different numbers of points within that
bounding box.

if people can do this and post the confidence number and coordinates that result
from calibration, that would be great. I expect that going from a small bounding
box to a larger one, we will see increases all the way out to the edge, but
going from small grids to larger grids, we will see rapid improvments at first,
but the improvements get smaller as the grid gets larger.

finding if my guesses are correct, and if so, where we stop seeing significant
improvements on grid sizes would be very useful information in setting the
defaults.

David Lang

that is why I think we want to not only get the calibration score, but the
coordinates of the anchors, as we step up the bounding box size and grid
density, we will initially see the score go down, but the anchor points moving
around significantly, but as we continue, the computed anchor points will stop
moving as much, and the score should start going back up again.

David Lang