Loco about Locos

I initially assembled the linkage with all the joints unpinned, so I could check that it all fitted and could move freely without any obstructions. Disaster!!! The angles that some parts of the motion were moving through were clearly wrong. The pendulum levers - which support the expansion link, and the link hangers were both visibly wrong. I checked all the components against the drawings - and discovered that the weighshaft -which supports the link hangers had been located in the wrong place on the frames- a dimension of 13/32 on the drawing had been set out as 13/16 in. (Actually, by the original maker of the frames -but I was supposed to have checked it). Everything else was correct - but -adding up the various dimensions on the drawing showed that the centres for the link hanger brackets were in fact wrong -by 1/8 in. Still, it made me read up and understand how Stephenson link gear is designed. To make matters worse, I'd drilled all the mounting holes around both items,and th...