New build with recycled parts on a ridiculous budget 120cm*60cm work area

[Desertboy]

I use 2 motors for my X axis, and I bought EM806 drivers primarily because of the stall detect. The EM806 is a later version, effectively, of the AM882. That stall detect has saved my machine from potential damage on a number of occasions when I've got something wrong. Typically, I've hit the e-stop because of some silly setup or gcode issue, and as a result the gantry has gone out of square. Not a lot, but enough to cause one end or other to bind on rapid feed somewhere along the rails. I've wired the fault signals from the stepper drivers into the motion controller and the whole machine then stops before any damage is done by one motor continuing to drive. Resetting and rehoming is a small price to pay. I reckon that if you are going two-motors rather than one-motor-and-a-long-belt, stall detect is pretty much essential.

Have you worked out how you will home the gantry so it is square?

I was going to assemble it first then fit (High quality) microswitches both sides of the gantry I need to work out where to fit them because I want them drilled into the aluminium so they can never move, had issues with 3d printer microswitches but they were super cheap, plastic printed mounts a nightmare on the Z. Conversly it's the X&Y that are the hassle with cnc with 3d printing they're nowhere near as important.

I've not looked at Mach 3 or linuxcnc but I have assumed that the microswitchs have some software adjustment to compensate for inaccuracy when fitting the microswitchs I know grbl (And even Marlin for 3d printers both Arduino based) does so would be shocked if they don't.

I figured one step at a time lol make router move and learn Fusion (These are at same time) then start with linuxcnc if I really struggle buy Mach3 but I'd rather use Linuxcnc been a linux used since 2005 big believer in opensource.

I did also consider inductive sensors like I set up on my printer for the Z axis but the microswitchs I'm looking at have very high repeatability and the difference in accuracy between them is marginal, when I checked the datasheets the inductive sensors had a slightly higher accuracy but lower repeatability and in the end they were both in the 0.01mm range with is probably better than my router will be lol.

I have no idea how to make sure the gantry is properly square though in the first place, pretty certain a set square isn't going to cut it lol.