Is it possible to tram X/Y squareness with fixed feet?

Hey Tom, hey Steven (@sdramer),

sure, that’s what it is. Geometry, instead of Comparing to a Reference Body.

But I find that like many youtube videos, it could be much shorter and denser.

…And if you specifically take the onefinity cnc with its four feet that one wants to put on a table top (i.e. a flat surface), it is much simplier. You wouldn’t even need a meter, just a stick which, by putting marks on it, allows to compare two measures: The one diagonal and the other diagonal, measured like in picture above.(1) When the diagonals are equal, it’s “squared”. The diagonals in a parallelogram differ, the ones in a rectangle don’t.

1.) But you are right, if you measure at the feet, you must be sure that the rail above is at a defined position relative to the foot

If instead, like in the video, you measure at the points where your bit drills a hole or your needle stitches the cardboard, you are the safest. That’s what I’m taking into account with this other method.