After some serious time & having to pack Mirror #1 up with 2 washers, I’ve managed to get the laser to this alignment for Mirror #3 (the focal point that aims downwards). Is this enough precision for all 4 corners (Top Left, Top Right, Bottom Left, Bottom Right)??
I’ve certainly operated with less precision with a K40 at my hackerspace which everyone thought they knew how to adjust the mirrors on.
That’s not bad. It’ll get you by.
All you need to keep an eye on is it staying so good mine moved every time I used it and it was all down to the fixings for the mirror mounts they had used odd screws even self tapping screws I tapped all the holes out and put new bolts in them all and it’s been fine since.