Author Topic: What's the deal with Clockwork Square Dimples?  (Read 322 times)

Offline S. Heslop

  • Hero Member
  • *****
  • Posts: 1154
  • Country: gb
  • Newcastle Upon Tyne
What's the deal with Clockwork Square Dimples?
« on: September 10, 2021, 10:52:43 PM »
I opened the cheap dial indicator since i'd foolishly left it next to the computer and it's inevitable curiosity would get the better of me. Thankfully it wasn't the kind of mechanism designed to explode. But inside I found The Squares again.



Alot of clockwork and clockwork related stuff (camera shutters, tape mechanisms, etc) is built from these plates with regular square dimples. Sometimes they're arranged specific to the part, away from holes and such, and sometimes it's like this where it was clearly in the plate before it was cut. But i've got no idea what their purpose is. Some kinda reenforcement? Equilizes stress? An old decorative 'symbol of quality' nobody dares drop? A hardness testing department that gets paid per reading? Extremely aggressive work-holding? Work hardens the material?

It's been bothering me for years but I was too embarrassed to ask since... it also looks like it should be obvious somehow, especially when it's so ubiquitous. I think at this point i'd be a little disappointed if the answer wasn't blindingly obvious..

Offline russ57

  • Full Member
  • ***
  • Posts: 248
Re: What's the deal with Clockwork Square Dimples?
« Reply #1 on: September 11, 2021, 01:43:42 AM »
I suppose if us amateur modders could buy it, assuming the dots are accurate, it would make layout easy.

But since those examples are almost certainly stamped, ive no idea either.
Unless they are an artefact of the press?

-russ


Offline Sea.dog

  • Full Member
  • ***
  • Posts: 179
  • Country: gb
Re: What's the deal with Clockwork Square Dimples?
« Reply #2 on: September 11, 2021, 09:35:34 AM »
I have an idea that it might be to add stiffness to the plate. I seem to recall reading something to that effect many years ago. I could, of course, be talking complete bollocks  :D

Online awemawson

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 8337
  • Country: gb
  • East Sussex, UK
Re: What's the deal with Clockwork Square Dimples?
« Reply #3 on: September 11, 2021, 01:15:11 PM »
I'd always though it was to restore flatness after previous manufacturing operations.
Andrew Mawson
East Sussex

Offline S. Heslop

  • Hero Member
  • *****
  • Posts: 1154
  • Country: gb
  • Newcastle Upon Tyne
Re: What's the deal with Clockwork Square Dimples?
« Reply #4 on: September 11, 2021, 01:50:48 PM »
I'd always though it was to restore flatness after previous manufacturing operations.

I took as close-up a photo as the phone could manage and...



It's hard to tell if stuff was dimpled before of after the stamping, for me at least. But there is some metal deformed out around that big hole, at about the 11 and 5 positions. So it does seem like it was dimpled after stamping, and that'd explain why.

Although now i'm wondering what you'd even call such a machine.

Offline philf

  • Hero Member
  • *****
  • Posts: 968
  • Country: gb
Re: What's the deal with Clockwork Square Dimples?
« Reply #5 on: September 11, 2021, 03:04:46 PM »
I found this on a clock and watch forum which more-or-less confirms Andrew's flattening theory:

"The process was called "Planieren" (planing, grading) and was used to roughen the plates
and relieve tension. Junghans applied for a patent in Germany in 1930 and actually received a Swiss
patent (152302) Jan. 31, 1932.
Starting with alarm clock movements, the dotted plates became more and more typical for Junghans after 1930,
depending on the movement.
The machines used for the process spared out drilled holes and bushings automatically, so that these would not
have been narrowed down or closed by the planing.

Source: "Uhrzeiten - Innovationen in Technik und Design" 2011 by Stadtmuseum Schramberg, Lixfeld & Raststätter, ff.

The German patent is DRP 529786, published July 1931."
Phil Fern
Location: Marple, Cheshire

Offline S. Heslop

  • Hero Member
  • *****
  • Posts: 1154
  • Country: gb
  • Newcastle Upon Tyne
Re: What's the deal with Clockwork Square Dimples?
« Reply #6 on: September 11, 2021, 11:53:12 PM »
Mystery solved! Thanks very much.

I always find these sorts of things interesting though. Like ways of constructing stuff that seems very specific to a sector of engineering.

Online awemawson

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 8337
  • Country: gb
  • East Sussex, UK
Re: What's the deal with Clockwork Square Dimples?
« Reply #7 on: September 12, 2021, 03:16:27 AM »
I’d be very interested to see the machine that puts the dimples in.

If it is just a flat platten and a multi spiked squashing thing it must be quite hard to make.

If it’s a single spike that is moved to each point then I’d expect the workpiece to curl rather than become flatter.
 
Andrew Mawson
East Sussex

Offline S. Heslop

  • Hero Member
  • *****
  • Posts: 1154
  • Country: gb
  • Newcastle Upon Tyne
Re: What's the deal with Clockwork Square Dimples?
« Reply #8 on: September 12, 2021, 05:57:11 PM »
Yeah me too. Searching for the word "Planieren" found a suggestion that it's a roller, which I wouldn't expect to produce flat parts so that might be nonsense.

But a roller or a plate would explain why they're always square dimples, since that'd be alot easier to cut as a grid of V slots.