New tensioners have been designed. 3 identical sets were made, 1 for the X-axis and 2 for the Y-axis.
Here you find the OpenScad file from which they were 3-D printed.
I show pictures of the X-tensioner only, the two Y-tensioners are less accessible by the camera.
View of the X-spanner from the front.
View from the backside of the machine.