Hello, im a little confused on the C-Beam dimensions. The pdf drawing from the pdf drawings folder that I downloaded has different dimensions then the ooznest pdf for the c-beam, as well as there is a difference between the slot in this rail in both of those files versus the other v-slot sizes (i.e. 20x20). They all show the slot being 9.16 mm wide but the second dimension where it goes down and angle tapers off I am getting different dimensions the pdf for the v-slot 20x20 shows 6.25, where as the pdf from open builds shows 6.79 and ooznest shows 6.773. I downloaded the sketchup model from the where house and it agrees with the 6.773. So my question is which dimension is correct? and why does this dimension not match the other V-Slot Rails? is it different on the c-beam for a reason?