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.

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

robgraham wrote:
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
My gfuess its similar to a friend of mine's work - reproducing old
metalwork for museums and historic conservation work.

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.