For me the vision encoder did improve accuracy in the manner that the difference between x and y axis has decreased. It was small, but after calibration itās even smaller.
I started printing the shrinking test by Alex-vG.
The average outside dimension in X: 149,82 so, 0,18mm too small.
The average outside dimension in Y: 149,92 so, 0,08mm too small.
The average inside dimension in X: 139.85 so, 0,15mm too small.
The average inside dimension in Y: 140,13 so, 0,13mm too large.
(This was the result after a first round of shrinkage compensation tuning with PLA).
So this is fairly accurate, and for most applications perfectly ok. However, I found that the Y axis consistently deliverd somewhat larger dimensions (between 0,1 and 0,2 mm on a dimension of approx 150mm) then X axis. I was curious whether the vision encoder calibration would be able to reduce that.
After vision encoder calibration I reprinted the exact same g-code, with same material from same spool. Results:
The average outside dimension in X: 149,77 so, 0,23mm too small.
The average outside dimension in Y: 149,77 so, 0,23mm too small.
The average inside dimension in X: 139.96 so, 0,04mm too small.
The average inside dimension in Y: 139.98 so, 0,02mm too small.
Based on these results, my conclusion is that the encoder was able to correct the mismatch between size in X direction and Y direction. The remaining mismatch between design and actual size can be tuned further with shrinkage setting. After that I had the following results:
The average outside dimension in X: 149,91 so, 0,09mm too small.
The average outside dimension in Y: 149,91 so, 0,09mm too small.
The average inside dimension in X: 140.05 so, 0,05mm too large.
The average inside dimension in Y: 140.09 so, 0,09mm too small.
I would call that perfectly accurate for a FDM printing process.