Hey Erik,
here I made this drawing the other day. It shows one winding stick, but of course you need two.
Generally, tramming by adjusting the front/rear tilt on three rails is difficult. You could remove the third “stiffy” rail and adjust the lower two rails, and then try to adjust the third “stiffy” rail.
To be sincere, I think that if you have a third “stiffy” rail, the middle rail is rather useless and can only slow the machine down if not properly in line with the others. The gain in stiffness by adding the third “stiffy” rail is in my opinion not caused by augmenting the number of rails, but by the greater distance between the third and the lowest rail.
I plan to test the rigidity of my X-50 Journeyman with the middle rail removed, so that you have two rails again, but with the greater distance that should make rigidity better, but at the moment I have serious health problems and cannot work in my workshop. Since on X-50, the third “stiffy” rail is attached with only one bolt on each side(!)(why did they design it with attachment by only one bolt?), I would have to first develop a method to attach it more firmly to the X axis aluminium extrusion profile ends before I can really get rid of the middle rail.
So it’s a bit difficult to answer the question. I think you would need to remove the third “stiffy” rail to use the winding sticks one the lower two rails. If you have them trimmed, then I would set the third “stiffy” rail loosely on top of the X axis without attaching the bolts and adjust the two ends of this third rail with their tramming grub screws so that the rail is in line with the others by checking if the aluminium extrusion profiles at each end sit flush where they belong on top of the X axis aluminium extrusion profile ends, and fix the bolts only then.
Note that on X-50 rails (unlike on X-35 rails), the third “stiffy” rail is not in line with the two others, as to be seen here.
On X-35 rails, the third “stiffy” rail is in line with the others.