We have a Tronxy X5SA 400 Pro which uses a TR sensor to "auto-level" the printing bed. It samples 16 positions across the bed (4 x 4) and provides a +/- level from its initial measurement. For example, it might produce a grid like this:
+0.280 +0.155 -0.108 +0.127
-0.267 -0.010 -0.005 -0.218
-0.114 -0.020 +0.004 +0.000
-0.143 +0.110 +0.253 -0.270
As you can see in this contrived example, measurements toward the center are closer to a Z-offset of 0 because that is what it samples first; toward the edge, it can be off by ~0.3mm. By turning the sprung leveling screws, I can usually get it to within 0.250mm across the bed.
However, 0.250mm variance is still too much for 0.1mm-layer prints because at the center it is right on, but on the edge it is 2-3x the layer height above the bed...or worse, in the opposite case, the head will crash if the bed curves in the +Z direction; thus, I have to babysit the first layer and manually +/-Z as needed.
Prints in the center of the bed are great, but adhesion can be poor on the first layer when it prints near the edge, and part thickness can be off by ~1-3 layers.
Question:
Is there a way to tell Cura about these 16x calibration points and have it adjust the print head with a linear extrapolation between points?
(I did find the Z Offset Setting plugin, but that appears to support only a single-valued offset.)
