Two other weldments, (a term used to denote components assembled by welding), are the pull bars no.'s 1 and 2. These consist of lengths of 40mm or 1(1/2)″ square steel tube cut to the appropriate dimension. In each case a piece of 12mm or 1/2″ square mild steel is cut and filed to fit just inside each end of the tubes. It is easier to drill and tap the M10 hole in each piece before welding the bits into place. In the case of pull bar no. 1 the centre hole is to be drilled 20mm diameter, to take a headed bush tapped M12. This bush is welded in position and is to take the M12 studding that is used to operated the rise and fall mechanism of the stand. M12 studding is easy to obtain from most large D.I.Y. stockists. If you use a different threaded screw then the bush will need to be tapped to suit. The centre hole in pull bar no. 2 is drilled 25mm diameter to take the thrust bearing assembly about to be described.
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