Another video of the Center Fork and Easing Off issues on my 1962 Draper X3 loom.
The center fork detects when the filling is not inserted into the shed properly, ie wrong tension or broken yarn. Then it shuts off the loom.
There are many things on an X3 loom that will shut it off when something is not right. When and where it stops can tell you why it shut off. Easing off is where the loom turns off for a reason other then normal.