Started my 72 x 2 Belt sander. I am not going to make knives, but I think it can be usefull for all the notching I have to do. The better the fit the easier and stronger the weld. I TIG all my suspension linkages.
I did not use square tubing because the fit of one tube into the other is too loose, so I machined down some 50 x 50 x 5 angle iron to give me a nice snug fit for the 38 x 38 x 4 square tubing I use to slide into the other manufactured tube. I inserted some 0.5mm spacers before welding up the angles to form the tube.
A friend of mine suggested I add some hinges so it is easy to flip it 90 Deg so the belt will run horizontally.