Which’s the prettiest of them all?
With every machine overhawl, comes with an extra dosage of mirror alignment. It’s boring and it’s slow…but it must be done.
I don’t really know what other people do to check beam position, I use thermal printer paper (and some tape).
USE MINIMUM POWER!
As said, use them (squares) as needed:
If I haven’t been clear:
And you will have to dissasemble the mirror and clean it thoroughly…again and again…