Very ingenious! Are the laser beams all parallel with each other? If off slightly might that cause a final alignment error?
The beams are parallel; I used sort of a "mask" (two pieces of cardboard, joined with duct tape) placed close to the lasers, and marked the laser spots. Next, moved the "mask" 170 cm away, and, using 4 screws on each laser, brought the beams to shine on the marked spots.
With such a distance, one degree spans 3 cm, and I was able to point the beams with better than 0.3 cm accuracy, therefore the beams are parallel with error of 0.1 degree,
I like to cut corners and simplify, but parallel beams was crucial for this project.
More error was introduced by these tiny rare-earth magnets, (I bought them from e-bay, one hundred cost me about 12 bucks),
as some of them are not exactly parallel - or, maybe the double - sided tape attaching mirrors to them, was not evenly thick?
The original aim of this project was to avoid scorching Sun, and have the Sun imitation stopped (sort of copying biblical Joshua).
Also watching, how the focal spot changes when dish is "off-axis" - and if there could be built special feedhorn, or scalar, able to "catch" the signal - even with strong "coma" distortion.
BTW, thanks for words of appreciation to all thread posters
Cheers, polgyver