On 26 May, 00:43, Matty F wrote:
I needed to make some square brass nuts to go with the screws that I
made earlier.
Usually I would put some hex bar in the lathe to drill it accurately
and chop off as many nuts as I wanted.
I didn't have any hex bar and I wanted square nuts. I had some 5/8"
square bar but I wanted 1/2" wide nuts.
How was I to drill the hole accurately when I had only a three-jaw
chuck?
As it happened I was able to use the three jaw chuck like this:http://i50..tinypic.com/2uhlu88.jpg* * * *DSC00133lathe.JPG

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

I finished tapping the hole by hand as the tap kept slipping in the
lathe chuck:http://i49.tinypic.com/1zb70c5.jpg* * * *DSC00135tap.JPG

Here's a finished nut on the screw that I made earlier:http://i50.tinypic..com/264rvap.jpg* * * *DSC00144nut.JPG

Here's the screw and nut in place on the bell unit:http://i45.tinypic.com/2h4evxc.jpg* * * *DSC00137bell.JPG

Everything but the screw and nut was cast in a foundry from an
original sample.

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.

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?

Rob