Need set screws for Sputnik camera front lens gearing

[aaron_muderick]

I have be happily modifying and updating my Sputnik camera but lost a few of the

set screws which hold the front lens gearing tight against the lens. Any idea

on where I could find replacements or at the least know the correct size so I

can ask? I went to the hardware store and purchased a few 0 gauge screws. They

sort of almost fit but not really. I think the size is right but the threading

is wrong.

 

Thanks!

[john_shriver]

http://www.boltdepot.com and http://www.smallparts.com are great sources.

 

The setscrews have a high likelihood of being metric. Metric screws are designated by their diameter in millimeters. These could well be M1.0, M1.4, or M1.7.

[charles_stobbs3]

You need to know the pitch as well as the diameter.

[mark f]

www.mcmaster.com I'm sure they are metric and you are unlikely to find them at the hardware store. McMaster has everything and everything is in stock (amazing)

[aaron_muderick]

Thanks for pushing me in the right direction. I measured the screw and it is 1.25mm in diameter and 2mm long. The thread pitch seems to be around .35 - .45 ish. Unfortunately, the smallest metric screw size McMaster Carr carries is 1.6mm and 3mm long. The screws are steel, the piece is aluminum. Perhaps I can 'make' it fit?

 

I think I'll check out a watch repair shop and see if they can find a good match.

[winfried_buechsenschuetz1]

These set screws can be a problem - sometimes they are even made of brass, and the slot breaks away very easily.

 

Anyhow, the thread surely is metric - the former Soviet Union was a completely metric country (they even did not have 3 1/2 inch diskettes but 90mm diskettes). So the pitch will be metric, too. Maybe a screw with similar pitch will make its way through the alloy thread. You can also try to cut a new thread (provided you find a tool).

[enric]

Well, knowing the type of screws is very easy. All that you need is a caliper, a metric one of course, or one of those that have both systems.

 

I was just looking for a missing screw of my Zeiss Superikonta. That's how I foudn the right screw:

 

Remember that screws are standardized, custom or in-house specific screws are very uncommon.

 

The type of screw that cameras use are almos all "machine screws".

Normally they will be pan or flat head and the can be slotted or phillips (the kind of screwdriver that fits). The latter is not specially important, the type of head can.

 

With the caliper measure the diameter of the tread. In my case the tread was 1.7mm in diameter (that's .669, roughly .7 inches).

 

Screws follow a standard notation, normally a letter and a number. Metric machine screws use the letter M, the minor diameter. Be careful here, what we can messure with a caliper is the MAYOR diameter, or tread diameter and the type is designed by the MINOR diameter (the depth of the tread).

 

Now what you need is to check the chart at the bottom of this page:

http://www.hager.ch/d/art/bn/bn1077.htm

 

The first column is the type we search, the second column is the diameter we measured with the caliper and the third is the diameter of the head.

 

Once we know the type (in my case M1.6, which is a pretty common screw in cameras) we can ask for it at the hardware store or search for it in the internet.