Join more laser beams for one high power beam

You know, when I read OP's name I indeed thought it was "Kenom"

as stated above a pbs cube stands for polarized beam spliting cube although if used in another way it actualyl combines two lasers that are horizontally polarized and vertically polarized

Would then using 3 cubes solve this problem...2lasers both 650nm go into one cube at 300mmw each "long can" combining giving 600mw out put for that cube and the same setup on the other cube as well giving 1200mw red output power and the out put beam of each cube combined by a 3rd cube giving a 1watt red 650nm laser in one focused beam! Reply back if possible....sounds good in theory!

You can't combine more than two lasers by using the theory that you have.

But you can by using this method. Quad RED module, home made, miniature size - Photonlexicon

Or by using the knife edge mirror method research it.

A PBS cube will take an unpolarized beam in one side and will split it into two polarized beams; one vertical and one horizontal. If you take two polarized beams (which the blu-rays and reds typically are) and go the other way, you can shine them into two faces of the cube and they'll come out of a third face overlapping/combined. In order for it to work you have to rotate each laser to the correct angle so that the polarization is correct. So one will be horizontal and one vertical. The combined beam will have, of course, both horizontally and vertically polarized components, so if you try to pass this through a second PBS, only one of them will get through. That's why you can't use multiple PBS cubes to combine more than 2 beams.

He nailed it

A simple 500 lines/mm grating will cost you $9 for a 6" by 12" sheet. Cut two squares out of it, and align them perpendicularly to each other. Mount in a frame. Shine the laser through them with a paper at 1ft/1m distance, then at 2ft/2m distance, measure and calculate the angle of each beam. Put up some spacers to suspend the frame over a wooden board. Cut some pegs at the right angles, and put mirrors on the pegs. One laser per mirror. Fiddle the mirrors until the beams are aligned at the grating.

This method will probably let you combine something like 25 lasers or so (I haven't calculated the number of orders at 660nm with a 500 lines/mm grating).