Setup for squaring twin X-axis gantry

[JAZZCNC]

I can't get my head round the fact that accuracy of the machine is down to the position and sensitivity of proximity sensors or switches.
I'm talking about repeatability I suppose, it's not so bad when there is one switch per axis but when there is a separate one for slaved motors it makes even less sense.
This is one area where absolute encoders are far superior and there are programmable limit switches based upon encoders but quite expensive.

Yep I agree 100% and exactly why I prefer screws connected Via belts has it's simple and accurate.! ...............Again thou it's down to usage and for machines which don't require higher accuracy or repeatabilty like routers just cutting wood, plastics etc then slaved motors are perfectly fine provided they are run within safe limits.

Edit: Daft as this may sound then if you want better accuracy from slaved motors than using switches just use Hard stops and slowly drive upto them before setting Zero.!