There are two set screws that hold the dichroic filter holder onto the dovetail of the cube. One of these is a typical set screw with a green Nylon tip, for tightening the dichroic holder in place securely. The other set screw has an acentric cam protrusion that can move the dicroic vertically. The dichroic holder should be as close to centered as is possible.

If the dichroic is centered vertically, alignment should proceed easilly with the three cube adjustment screws being close to the center of their travel (the dichroic cube, not the camera cube).

Don't use 1.5mm wrench! Disconnect C-mount adapter from the tube lens body.