For the videos, I would say you need more weight, but add carefully, like replacing the hollow bricks with solid ones.
Is the frame angled at 15°?
Did you change to a 12 foot top beam?
What about the bottom of the sled, a little rub with candle wax can help, or thin UHMW to get less friction on the sled.
A change to
will sure help with the wrong measurements, specially if the calibration is done 2 or 3 times.
There is a new software around the corner, but not sure when it will be ready for production.
If you want to join in in testing, the post is here:
Kind regards, Gero
Edit: I’ve abused my admin rights to correct the link in your first post to the ‘left’ video, as both links pointed to the ‘right’.