I am trying to buid a accurate 45 deg mitre sled. I recently tried to use mitre saw and it is precise on smaller widths but if I go over 5”, there is slight drift on the outside edges and they are sightly off. I think a precision seld will eliminate this. I have a problem finding a true precise 90 deg setup to help in setting the sled up. I have all items and ready to assemble. I am using the 3,4,5 setup to get the 45 deg angle and T-track sliders for mitre slots.
What is the best way to set this up to get the percision I am looking for?