In the documentation for 20x20 t-slot profiles, an accuracy on the cut of 0.5 mm is given. If I am not mistaken in my interpretation of the figure, it follows that a maximum difference of 1 mm could occur between two elements of the same theoretical length. In that case, in going to assemble a frame for a Voron 2.4.... could I not incur an out-of-square such that it would interfere with the operating tolerance of the recirculating bearing guides and on the accuracy of print orthogonality ?
The +/- 0.5mm tolerance is meant on each individual size entered into the system and then ordered, as this is a possible initial error in machine positioning. It is not a +/- 0.5mm error that can be accumulated on every part cut of the same size, as once set to a specific size the parts all come out identical with virtually zero error (we are in the range of +/-0.1mm for parts of the same size cut sequentially).
In the case of a 3D printer frame, particularly that of a Voron, where there are two structural profile measurements (the 8 perimeters and the 4 columns at the corners) there will be a maximum error of +/-0.2mm (between two elements of the same theoretical length). This tolerance on the cut will not interfere with the general sliding system and operation of the machine as it will not affect more than the operator himself when assembling and squaring the frame.