On May 26, 8:49 pm, robgraham wrote:
On 26 May, 00:43, Matty F wrote:

Then I milled the bar down to half an inch and the hole was in the
middle!http://i46.tinypic.com/2f0bzfb.jpg DSC00134mill.JPG

In fact you solved the problem more neatly than if you had had a 4 jaw
independent chuck which I would have reached for, as you only had one
milling operation.

Actually I milled 1/8" off one side of the bar and 1/16" off two
sides, to get a 1/2" square.
The job was too small to go out and buy exactly what I wanted, and I
would not be able to buy such a small quantity. I tend to design jobs
around what materials that are lying around.

Thanks for the WIP photos - you never know quite when something like
that might be useful.

What I am left with however is the puzzle over how the bell works and
what it's for - and finally why the reproduction?

There's a lever that is yet to be attached, that pushes the knocker
down when a cord is pulled, on a tram. We got one bell from somewhere
and needed to make three more. I can't remember the details but a bell
is needed at each end of the tram because the driver swaps ends, and
two more bells because it's a two story tram.