Posted by Emgee on 28/04/2021 13:53:21:
….so much better if the corner joints had been mitre joints, that really would be a proper job.
That's a lot of work for no benefit. The CNC mill sits on the four pads in the corners. So most of the load falls on the end frames. The way it is designed the end frames are stable without the welds. The welds simply keep things aligned, they don't take a significant load, as they would if the joints were mitred.
Andrew