El Beast - Initial design phase, comments and critique welcomed!

[Zeeflyboy]

Indeed, it doesn't guarantee alignment to the bed, but to the rail/carriages... which are aligned separately to the bed. If the plate was at an angle to the rail/carriages the readings would change as it moves past - I can actually demonstrate that by inducing an angle.

If measuring to the bed then yes, it needs another point of reference... but moving the indicator is enough to induce a small change just when it comes down into contact with a different part of the plate so that's not quite so easily done. I figure it's easiest for me to align the rails to the bed, then align the side mounts to the rails.