I made a mistake
The error was in my guess at how the gears meshed. The drawings shows what I did wrong
This was because I thought that I "knew it all" instead of checking and checking again.
At first I thought I had two options, to make a new big gear
smaller than the one I had made so that it would fit into the distance I had between the bearings.
The second option was to make a new side
I then woke up in the night and thought that I could extend the sides I had made. The trouble is the sides are triangles.
I then remembered how my mum extended the sleves on my school shirts during the war. she added a "T" shape into the sleeve to take care of the tapper in the sleeve.
this was the solution the second diagram shows the solution.
The two pics show the first castings of the crane.
If you do not look too closely " you will not see the join"