Drawn pinion rod?

[speelwerkParticipant @speelwerk]

Sometimes on clock fairs or as now on ebay **LINK** you come across long lengths (33cm) of pinion rod, anyone know how this was made, probably drawing or was it with a cutter? Niko.

[speelwerkParticipant @speelwerk]

[roy entwistleParticipant @royentwistle24699]

Speelwerk It was usually drawn and needs work on to form the pinions This was usually done by filing

I personally have not seen it at any clock fairs in the UK

Roy

[speelwerkParticipant @speelwerk]

Roy, Thank you for letting me know, I have a few lengths but sofar never found use for it, do not know what type of steel it is made of, but it is very soft. Niko.

[roy entwistleParticipant @royentwistle24699]

Niko You should find that after filing a pinion to size etc it should be possible to harden it by heating to cherry red and quenching Remember that clock makers whilst having specific tools didn't have much sophisticated machinery

Roy

[speelwerkParticipant @speelwerk]

Clock makers may not have much sophisticated tools but I have great respect for people who can make the finest things, clocks or other, with basic tools. Niko.

[Mark CParticipant @markc]

Niko, I have been involved with wire production in the past and I doubt if the smaller profiles are drawn if they are carbon steel (reading Roy's post) – you would need a lot of dies in the die train to get the shape to fill and you would need to inter anneal a number of times on the way to the finished product.

Mark

[Michael GilliganParticipant @michaelgilligan61133]

Mark,

I've found it at last …

Have a look at illustration 2.21 in this book

MichaelG.

[Mark CParticipant @markc]

Michael, the problem is not the larger tooth counts it is the teeth with root undercuts. trying to get the material to flow into this form would require a large amount of effort in both design and production. It would more likely be hot worked and then finished drawn cold to work it up some. I used to work at a wire manufacturer and the senior guy had all sorts of fancy shapes (including a number of rail sections for scale railways). All the same, the undercuts on the small pinion would have probably prevented us from making it (and we had modern kit and carbide dies!).

Mark

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Mark C on 04/01/2014 17:39:39:

Michael, the problem is not the larger tooth counts it is the teeth with root undercuts …

Mark

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Mark,

Sorry, I don't get your point: The picture include one drawplate hole for a six tooth pinion.

Every Horological reference That I've seen describes steel pinion wire as "drawn".

The important thing is … Pinion Wire [for Clocks] is not a finished component; it's raw material to "make from".

MichaelG.

[speelwerkParticipant @speelwerk]

I think Michael has the answer, it must have been drawn, google it and you get even a supplier **LINK** of new. The smallest I have has 6 teeth with diameter of 1.2 mm and the largest is 8 teeth by 2.4 mm. The surface is beautiful smooth and it needs only turning the pivots etc. Niko.

[Mark CParticipant @markc]

Michael, Niko, I had a look and found a patent specific to this type of product – it is sized but it is not drawn in the conventional sense where you take a round wire and reduce it in CSA and shape as it passes from one die to another. The pinion is pre-formed by radial compression (which is how the undercuts are made possible) and then sized through a finishing die or two. Look at **LINK**

Normally you would expect to reduce CSA roughly 10% at each die and there is the problem – how do you get enough material into the flanks of the teeth and still get back to size with the undercut? The pinions without undercuts (continuously reducing tooth section) could be drawn on a conventional wire drawing rig but even these would be problematic unless the material was very easy to form. I looked at the old book drawing mentioned – I would love to see that system work for real, just getting from round to square takes enough effort and planning never mind getting pinion shapes in one pass….

Mark

[Michael GilliganParticipant @michaelgilligan61133]

Mark,

Thanks for the link to that Patent … very interesting.

Now: If you click on the "Find prior art" button, one of the links takes you here.

Admittedly, he is only making Brass pinion wire, and he is using cutters rather than formers [which is why I didn't mention it before], but I think you will be impressed.

"Drawing" of wires and tubes is a fascinating topic … perhaps you could tell us a little more about the modern processes.

MichaelG.

.

P.S.  Don't believe Google when they tell you there is no eBook available

 

Edited By Michael Gilligan on 05/01/2014 09:01:22

Edited By Michael Gilligan on 05/01/2014 09:06:54

[MICHAEL WILLIAMSParticipant @michaelwilliams41215]

Don’t know how pinion wire was actually made but material of similar shape is still made to this day for engineering components .

Three common processes :

Shaving dies – these progressively cut the shape from initially round bar .

Die extrusion – for more easily worked metals .

Simple milling for small quantities .

The pinion wire that I have seen has been a bit rough and I’d certainly want to use something better myself . Could probably make some on ordinary lathe / mill but there are several designs available for little pinion mills .

Don’t know whether clock pinions should be hardened – there are arguments for and against .

MikeW

[roy entwistleParticipant @royentwistle24699]

Mark Niko Michael etc The undercut was done by filing as was the rounding off of the tops of the teeth The pinion wire was only the raw material to start with particularly with clock makers I have no experience with watch makers

Roy

[Michael GilliganParticipant @michaelgilligan61133]

Posted by roy entwistle on 05/01/2014 09:59:23:

Mark Niko Michael etc The undercut was done by filing as was the rounding off of the tops of the teeth The pinion wire was only the raw material to start with particularly with clock makers I have no experience with watch makers

Roy

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Roy,

Yes, I made that point to Mark .. [04/01/2014 19:00:52]

But it appears that Niko has some modern Pinion Wire that is finished profile.

See post: [04/01/2014 19:14:28]

I say "appears", because it's quite small, and detailed examination under the microscope may prove otherwise.

MichaelG.

[MICHAEL WILLIAMSParticipant @michaelwilliams41215]

I forgot to mention that in high volume production material like pinion wire and indeed much larger bar for real gear pinions is often made by a continuous roller swaging process .

Two varieties :

Simple rolling and spiral rolling .

[speelwerkParticipant @speelwerk]

What I have looks to me the finished profile, I can not see how I can improve it with a file, how old it is I do not know. It is a little to small for what I normally need in the work I do (restoring musical boxes). Pinions I always harden, then polish before tempering to light blue. Niko.

Edited By speelwerk on 05/01/2014 16:00:03

[Michael GilliganParticipant @michaelgilligan61133]

Posted by speelwerk on 05/01/2014 15:59:12:

What I have looks to me the finished profile, I can not see how I can improve it with a file …

.

Thanks for the confirmation, Niko

We will keep digging !!

MichaelG.

[Michael GilliganParticipant @michaelgilligan61133]

For those interested: Here is a brief description of how traditional Pinion Wire was used.

… I still can't find a detailed description of how it was made.

MichaelG.

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Edit:   A few words about the process, here

" … as many as fifty drawings … "

Edited By Michael Gilligan on 05/01/2014 19:17:59

[John Ockleshaw 1Participant @johnockleshaw1]

Up until the late 1980's Birchington Engineering of Kent produced precision cold drawn sections in steel and other materials. They made pinion wire from 0.0625" to 0.75" diameter in steel and brass with involute and cycloidal tooth forms.

In the magazine Machinery, volume 83 for the 17th July 1953, there was an 9 page article about their products, the equipment they used to make them and the way they produced dies as well as other useful information about cold drawing.

If anybody is really interested and cannot get access to the magazine send me your email address, by PM, and I will forward a copy.

I followed their methods to make hexagon stainless steel "wire" for BA bolts and nuts, 4 BA to 12 BA.

[Michael GilliganParticipant @michaelgilligan61133]

John,

Yes please, … I have just sent you a PM

MichaelG.

[speelwerkParticipant @speelwerk]

Yes John, that would be interested reading, so asked you also for a copy. Niko

[Mark CParticipant @markc]

Michael, I don't know anything practical (other than what I was taught) about tube production or soft metal wire production such as copper etc. My experience is related only to spring steel products – hard drawn and rolled sections – and some limited mild steel rolling of profiles. It was all done at relatively high speeds, drawing runs from circa 600 ft/min and rolling half that speed. All the stuff we used to make was large production – a rod at a time with rods being welded together end on end and the joint cut out at the finished end (rod = 2 tonne mill stock coil – the sort of thing you see stacked on the back of trucks with the coil being some 4 ft dia. and perhaps 6 ft tall).

We would take annealed spring steel and draw it down to produce either a hard drawn (work hardened) or heat treated (either soft annealed or harden and temper) wire or process it further by rolling it in a set of opposing rolls on one or two axis simultaneously to produce trapezoids or prismatic forms along with ovals and round edge flats. Rolling and drawing is done in stages and roll sets are normally linked together in a series machine to allow multiple operations and passes as there is a limit (normally about 10% reduction of CSA) on how much work can be done at a single pass.

The material would often require HTreatment after drawing or rolling and this was also done in a continuous process – the last company I worked for used to make very high quality spring steels and I understand they were one of the last companies in the UK to provide "lead patent" wire which was quenched in lead rather than oil or air – producing the finest quality spring wire available at the time.

As an aside, we used to make oval spring wire that was some 3 x 1 mm (major/minor axis) and this was always one of the most demanding products we made. It had a very specific use….. it was formed into bra stay wires!

There is a huge amount of knowledge involved in this area of manufacture and a lot of it is propriety, if you have a specific question I would be happy to try and help but it would take a lot of time and effort to try and document the whole process.

Mark

[Michael GilliganParticipant @michaelgilligan61133]

Thanks, Mark

MichaelG.

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