[AstralTraveller (David)]

Does anyone know how to collimate a set of WO binoviewers?

They are out of alignment in the vertical direction. When I shine a laser collimator through them and onto the wall the two dots are offset in the vertical direction. I have managed to use them on the moon but my wife can't get the images to merge. The other night I tried them on a star and I could get the images to merge (perhaps I was tired, perhaps a star is harder to merge than the moon).

I have found a rubber cap on the underside. Behind it is a grub screw. There is also a metal cover on the top but I can't remove it easily. To me it looks like the grub screw would be working against a spring. However moving the grub screw doesn't affect the separation. I need to loosen the screw to improve the collimation. I didn't try tightening it in case it just made things worse and then wouldn't move back again.