Not being happy with how the laser pointer was held in the jig, I finally did what I should have done all along and that is use the laser’s own mounting bracket. The bit of aluminium angle bolted to the round jig gets clamped by the red bracket’s captured screws (not visible in pic). Now I can adjust the beam so that it is pretty well aligned with centre of jig. Previously the best I could do was a 1 cm circle, over the 1.285 m between flanges, when jig rotated on flange. The thing on the left is the crude reference jig that sticks onto the the flange opposite and shows the laser dot.
shooftie 