Comments sought on new build: A CNC Router for RC Gliders and Planes

[EddyCurrent]

How do you plan to get the gantry at exactly right angles to the rails ?

[njhussey]

How do you plan to get the gantry at exactly right angles to the rails ?

I am going to clamp a piece of Aluminium sheet to the gantry back and use a large engineers square off the reference rail (bolted down) to square it.

The reference rail will be parallel to one 100x50 x axis rail so I might get a DTI and reference the 100x50 rail carriage off the rail side and then bolt that down firmly (threadlock) to the carriages before referencing the gantry.