Door knob collar

[PlasmaParticipant @plasma]

How to replicate this item

[PlasmaParticipant @plasma]

Hi all,

Small project for the woodhouse.

Many of the original door locks and furniture have been lost over time.

I need to replicate a number of these disc like face plates which have a dished face.

I can part off each disc from brass bar but I'm wondering about the best was to make the curved detail.

Any ideas would be much appreciated, looks like the original was cast.

[Brian OldfordParticipant @brianoldford70365]

How many do you need to make?

[JasonBModerator @jasonb]

Just grind up a form tool, back can be left flat.

[RobCoxParticipant @robcox]

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

[JohnFParticipant @johnf59703]

Plasma, depends on the size of lathe you have but assuming a smaller machine I would cut off suitable size piece from the bar stock, use soft jaws bored to accept the billets then use a form tool to make the large rad — probably face up and centre drill to use the tail stock for added support. Then drill and bore the hole and recess – ensure recess is a consistent size.

Next make an expanding mandrel to mount in the chuck so that you can mount the part on the larger recess then face up and produce a small – say .010" – .-020" recess to make sure it sits flat on the wood. The rest is easy – holes etc

Hope this helps John

Faster typer's than me !

Edited By JohnF on 15/05/2019 19:42:55

[not done it yetParticipant @notdoneityet]

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

[PlasmaParticipant @plasma]

Gents,

I have a pair of Boxford X10s and a model L S&B with internal step chuck so holding it should not be too much of a problem.

I had though of a form tool, or series of tools for the S&B capstan reform different aspects of the shape.

At first I need 4 in number but bearing in mind the house has in excess of 365 rooms, each with at least two doors (state rooms even have false doors that do nothing but achieve symmetry) I think I may be making a few more.

The three holes are later additions as the two holes inside the knob shank would have held the face plate invisibly, but not after a few hundred years of wear.

Sorry if I'm using poor lock terminology but I'm no locksmith.

Best regards Mick

[Michael GilliganParticipant @michaelgilligan61133]

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

[John HaineParticipant @johnhaine32865]

CNC. Or make a press tool?

[pgk pgkParticipant @pgkpgk17461]

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

[Neil WyattModerator @neilwyatt]

Plenty of look-alike brass doorknobs out there…

[Jeff DaymanParticipant @jeffdayman43397]

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

[HopperParticipant @hopper]

It's easy enough to turn those types of concave curves with a ball turning tool with the tool bit extended beyond the pivot point.

[Brian OldfordParticipant @brianoldford70365]

Posted by Michael Gilligan on 15/05/2019 20:49:43:

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.

.

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

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Brian Oldford on 16/05/2019 08:16:33:

As a patternmaker I find no shortage of brass foundries. …

.

That's good to hear, Brian

MichaelG.

[Paul LousickParticipant @paullousick59116]

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.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Plasma on 15/05/2019 20:32:09:

At first I need 4 in number but bearing in mind the house has in excess of 365 rooms, each with at least two doors (state rooms even have false doors that do nothing but achieve symmetry) I think I may be making a few more.

.

Paul, ^^^

Four … maybe going on hundreds

MichaelG.

[Perko7Participant @perko7]

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.

[PlasmaParticipant @plasma]

Definitely not spun or pressed on the original.

Paul I am fancying your idea, I have one of Eccentric engineering Turnado turning systems for free hand sphere turning and I think I may be able to utilise it in this project

I will let you know how I get on and the results .

Many thanks

Mick

[Brian OldfordParticipant @brianoldford70365]

Posted by Plasma on 16/05/2019 11:26:22:

Definitely not spun or pressed on the original.

Paul I am fancying your idea, I have one of Eccentric engineering Turnado turning systems for free hand sphere turning and I think I may be able to utilise it in this project

I will let you know how I get on and the results .

Many thanks

Mick

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

[Ian S CParticipant @iansc]

Get them cast, make one as a pattern, or even a number of them, they can be made of metal, aluminium or brass, or plastic or wood, leave the back flat is the easy way that's what I did when I had 200(twice)horse brasses cast for the souvenir shop at the local museum.

Ian S C

[Brian OldfordParticipant @brianoldford70365]

Posted by Ian S C on 16/05/2019 12:45:08:

Get them cast, make one as a pattern, or even a number of them, they can be made of metal, aluminium or brass, or plastic or wood, leave the back flat is the easy way that's what I did when I had 200(twice)horse brasses cast for the souvenir shop at the local museum.

Ian S C

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

[PlasmaParticipant @plasma]

A good bit of manual dexterity and hey presto, looks ok but will need to check it against the centuries old door knobs.

[Rik ShawParticipant @rikshaw]

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!

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