Blue was always the problem before, but now I've got plenty of blue to spare and the challenge is getting enough red. I know I can combine a set of red diodes with a polarizing cube but I'm curious if works to combine the diodes *before* collimating, then put the resulting beam through a single lens? In addition to reducing cost, it would simplify mounting and alignment and result in a more compact assembly. Having never tried combining beams though I really don't know if it would work. I suppose even with the diodes almost touching the cube, you might end up with too much distance for the focal point of the lens.