How many do you need to make?

A form tool might be too much of an ask for that large a curve, so I'd opt for shaping it freehand with a graver. Depends how confident you are with freehand turning. I've 20+ years of woodturning experience and have used that to shape machine handles from steel, so a bit of brass shouldn't be too difficult.

Rob

You could make them in aluminium and coat them with one of those ‘patina’ solutions. A cheaper option, or maybe not…

With those quantities … Casting might actually be a realistic proposition

H&S legislation limits what can be done in the UK, but India does a lot of Brass.

MichaelG.

.

Edit: a few moments on google returned this list:

https://m.indiamart.com/impcat/brass-castings.html

Edited By Michael Gilligan on 15/05/2019 20:54:43

They look awfully familiar somehow…
Of no idea if it helps but there used to be a shop between barnes and putney (london) called knobs and knockers (don't think it was a brothel) but lookig for it on line I found this link: **LINK**

Or a salvage yard 'cos they look like a stock common item…?

pgk

+1 for press tool, preferably run in the brothel pgk pgk mentioned. (more strokes per minute in the press, when run there)

As a patternmaker I find no shortage of brass foundries. I'm always geting small runs of broadly similar bits cast. Once  polished they'd be virtually indistinguishable from the originals. PM me if it helps.

Edited By Brian Oldford on 16/05/2019 08:18:02

Edited By Brian Oldford on 16/05/2019 08:18:58

Mick,

Making special tools (form, ball turning, CNC, casting, etc) seems to be a lot of work for only 4 plates. Turn the middle and the outer edge of the plate and do the curved section by hand by adjusting both the X and Y direction of the cutter at the same time. It does not have to be precision work and you can smooth up any discrepencies with emery paper. Use a cutter with large radius tip for the free hand work. Cut a profile from cardboard to check the shape of the curve. Then part off the plate from the stock bar.

Paul.

Original probably stamped, but would metal spinning over a suitable former be a better solution? I know very little about it other than what I've read in some books but it seems like a possibility.

Looking at the unseen face the originals definitely look sand cast. Everyday stuff.

With small stuff that's OK but doing that with larger stuff creates dimensional errors due to shrinkage between solidus and ambient.

As we are on door knobs may I chuck my three penn'orth in. Some years ago I found myself in a field near Yeovil on a Sunday afternoon and bought a lovely old lead crystal inkwell from a bloke standing behind a pasting table.

It was incomplete and only carried a hinged collar thus:

In position it looked like this:

I wanted to make it look something like it should have been originally so I fettled an eight ounce brass scale weight on't lathe and got this:

which sits in the collar so:

The brass door knob was next for butchery and ended up like this:

The end result here:

The job is not yet finished as inspired by a recent thread on silver plating brass etc . I intend to silver the brass parts. The object of the exercise is not to deceive but merely to show what an old bloke in his shed gets up to when trying to avoid doing housework and stuff!