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A question about engraved letters on lenses
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PostPosted: Sun Oct 26, 2014 9:50 am    Post subject: A question about engraved letters on lenses Reply with quote
Almost all old lenses have beautifully and accurately engraved brand names and focal distances etc.
Is it done robotically?
I can't understand, there is usually a curved surface, so the machining head needs to have complex movement. The precision is also very high.
Was that possible in 50's and 60's? What equipment was used?

Example:



Last edited by nandakoryaaa on Sun Oct 26, 2014 11:29 am; edited 1 time in total


PostPosted: Sun Oct 26, 2014 10:10 am    Post subject: Reply with quote
The engraving would be done with a pantograph mechanism like this:



The company name, etc. is laid out on a big pattern and the pantograph mechanically reduces this (a large movement from the engraver tracing the the pattern with the input side results in a tiny but proportional movement on the output side) for a perfect engraving.

In the old days the pantograph would be worked by hand with an engraver manually tracing the pattern - very time consuming. Now I'm pretty sure it is done by computers and robots. Starting in the 60s a lot of companies replaced engraving with silk-screened letters/numbers to save time. I am also sure that around the same time some companies simply had the words cast into the ring when it was made.

Last edited by Mos6502 on Sun Oct 26, 2014 10:16 am; edited 2 times in total


PostPosted: Sun Oct 26, 2014 10:14 am    Post subject: Reply with quote
Thank you, that was quite enlightening! Smile


PostPosted: Sun Oct 26, 2014 11:15 am    Post subject: Reply with quote
Back in the early 1970's I worked for a company making time switches and parking meters, much of the production was tiny and precision, a lot of the products were still using traditional wind up clockwork mechanisms. The dials to set the times were sometimes made with a fully automated pantograph machine - automated in as much as a machine setter would have to set the master dies in place for the machine to engrave the dials, some only 40mm in diameter and intricately engraved.

Other dials were simply pressed into shape with tooling that embossed the dial, this was generally aluminium whereas the the engraved were brass.

Today a CNC machine would churn engraved lens rings out at a speed that would be astonishing to us old school engineers.


PostPosted: Sun Oct 26, 2014 11:59 am    Post subject: Reply with quote
There is another curiosity concerning the name design.
I have noticed at least three brands which are written in a different style, where letters are connected to each other as if the engraver head was not lifting.
These are Pentor, Raynehe and I forgot the third one but I'm sure I've seen it too.
Could they be coming from some particular manufacturer? I've been told than Raynehe is a Korean made lens, can the other lenses with such distinctive writings also be Korean?




PostPosted: Sun Oct 26, 2014 12:45 pm    Post subject: Reply with quote
As a Zeiss nerd for decades I'm pi...sed of in an indiscribable kind:
The change of Hasselblad from C Type to CF in the eighties did end the engraving of meter & feet scales to only painted on numbers.
I could puke the whole day seeing the markings vanish after some years of use.
Especially the distance markings on a SWC are partly not to be seen any more: You have to guess what distance You are focusing on.

An excellend example of controller's idiocy: economize the engraving and loose customers!

Todays Zeiss lenses made by Cosina/Voigtländer are an enjoyment again: Clean engraved numbers, durable for decades!

Last edited by duckrider on Mon Oct 27, 2014 1:12 am; edited 2 times in total


PostPosted: Sun Oct 26, 2014 1:44 pm    Post subject: Reply with quote
Interesting but I would like to know how they quickly put all the tiny screws in a camera...maybe they had cards with the screws embedded in, to hold them while screwing in...what a boring job.


PostPosted: Sun Oct 26, 2014 2:16 pm    Post subject: Reply with quote
Excalibur wrote:
Interesting but I would like to know how they quickly put all the tiny screws in a camera...maybe they had cards with the screws embedded in, to hold them while screwing in...what a boring job.


There's much more mistery in how they assemble the aperture unit Smile I once had to do that for a P6 Zeiss 50/4, and it was pure hell, took me half a day to complete.


PostPosted: Sun Oct 26, 2014 6:48 pm    Post subject: Reply with quote
nandakoryaaa wrote:
Excalibur wrote:
Interesting but I would like to know how they quickly put all the tiny screws in a camera...maybe they had cards with the screws embedded in, to hold them while screwing in...what a boring job.


There's much more mistery in how they assemble the aperture unit Smile I once had to do that for a P6 Zeiss 50/4, and it was pure hell, took me half a day to complete.


Shocked Shocked The reason tiny screws were in my mind was because the other day had to fit the tiny screws (ones that had no head) back on a curved surface on my zoom, well I taped all around the holes and that held the screws in position.....not a good idea for mass production though Wink


PostPosted: Sun Oct 26, 2014 7:04 pm    Post subject: Reply with quote
Excalibur wrote:
The reason tiny screws were in my mind was because the other day had to fit the tiny screws (ones that had no head) back on a curved surface on my zoom, well I taped all around the holes and that held the screws in position.....not a good idea for mass production though Wink


Yes I've been through that many times. I use try-fail-repeat approach Smile Simply putting the screw near the hole and then playing hockey trying to push it into the right position with the screwdriver.


PostPosted: Sun Oct 26, 2014 10:13 pm    Post subject: Reply with quote
In USSR, most of workers in lens factories were women. Maybe that's the key. If you want to re-assemble your lens, ask your wife, you may be surprised Very Happy


PostPosted: Sun Oct 26, 2014 10:21 pm    Post subject: Reply with quote
BurstMox wrote:
In USSR, most of workers in lens factories were women. Maybe that's the key. If you want to re-assemble your lens, ask your wife, you may be surprised Very Happy


Actually, my wife wanted to do it. But I knew how it will end Smile


PostPosted: Sun Oct 26, 2014 10:23 pm    Post subject: Reply with quote
nandakoryaaa wrote:
Excalibur wrote:
The reason tiny screws were in my mind was because the other day had to fit the tiny screws (ones that had no head) back on a curved surface on my zoom, well I taped all around the holes and that held the screws in position.....not a good idea for mass production though Wink


Yes I've been through that many times. I use try-fail-repeat approach Smile Simply putting the screw near the hole and then playing hockey trying to push it into the right position with the screwdriver.

Magnetising the screwdriver helps a lot! Smile


PostPosted: Sun Oct 26, 2014 11:41 pm    Post subject: Reply with quote
Excalibur wrote:
Interesting but I would like to know how they quickly put all the tiny screws in a camera...maybe they had cards with the screws embedded in, to hold them while screwing in...what a boring job.


Assembling the time switches, the screws were always made of steel and the screwdrivers magnetic. I always rub my screwdrivers on a magnet when putting lenses back together.


PostPosted: Mon Oct 27, 2014 12:12 am    Post subject: Reply with quote
duckrider wrote:
As a Zeiss nerd for decades......
I could puke the whole day seeing the markings vanish after some years of use.

I don't know about puking all day, but my stomach would definitely turn over.
It is pure joy to use a lens that had the little details way over engineered.


PostPosted: Mon Oct 27, 2014 9:26 am    Post subject: Reply with quote
Lloydy wrote:
Excalibur wrote:
Interesting but I would like to know how they quickly put all the tiny screws in a camera...maybe they had cards with the screws embedded in, to hold them while screwing in...what a boring job.


Assembling the time switches, the screws were always made of steel and the screwdrivers magnetic. I always rub my screwdrivers on a magnet when putting lenses back together.


I'll have to try that next time to see if a tiny screwdriver has the magnetic power to hold the screw..it had to be tiny as the screw was going deep into the hole...but thinking, I suppose I could start it off with a larger screw driver and then use the smaller one.


PostPosted: Wed Oct 29, 2014 10:27 pm    Post subject: Reply with quote
BurstMox wrote:
In USSR, most of workers in lens factories were women. Maybe that's the key.


Interesting. When I cruise the Internet about lens manufacturing/assembly the photos most often show women doing the work -- operating machinery, fine hand tools, etc. Same with IBM in the 1950's/1960's where most of the employees hired and trained to do very technical programming work were women.


PostPosted: Wed Oct 29, 2014 10:39 pm    Post subject: Reply with quote
That's because women are more tolerant to repeating process



PostPosted: Wed Oct 29, 2014 11:28 pm    Post subject: Reply with quote
Women doing the work - more likely to be due to very low pay, and 'piece work' - getting paid by the quantity / speed. Which leads to people assembling things that they know are defective just to get the quantity up.
The men were better paid, and set the machines, and did the quality control, which I did for a few years in various factories where female labour did the poorly paid assembly or machine minding, and if they were on piece work the quality controllers had to turn the damn machines off to stop them producing crap. We regularly used to get hit, slapped and have things thrown at us when we stopped them working. It was a nightmare, and obviously the quality of the final product suffered hugely. Today, even though many factories still use piece work, they now incorporate the responsibility of quality control to the individual doing the task, if they make crap they not only don't get the piecework rate, they go on to a lower rate while they sort out the bad components.
Quality control in the 1970 - 89's was a joke in most manufacturing. And I doubt that lens and camera manufacturers were any different, quantity was king.


PostPosted: Thu Oct 30, 2014 1:13 am    Post subject: Reply with quote
nandakoryaaa wrote:
That's because women are more tolerant to repeating process


Nothing more sexy than a woman handling a firearm. But that's another topic. Smile


PostPosted: Fri Oct 31, 2014 8:12 am    Post subject: Reply with quote
Here in Germany the most successful grocery chain is "ALDI".
They did not use scanning cash register 'till ~five years ago.
Exclusive female cashiers had to memorize price of each item!
Those women were as fast as light keying in the price into the register checkstand and shove on the goods into the supermarket trolley.

Since they changed to scanning cash register men also are able to do this work! Embarassed
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