Copal Sinar Norma stuck open

**Daniel Unkefer** · 15-Oct-2016, 11:14

http://www.largeformatphotography.in...d-Camera/page8

There are some pages from the Norma Shutter Repair Manual in this thread. ^^^^

**Steven Tribe** · 16-Oct-2016, 00:52

Where in Denmark?

Note my location!

**jimsinar** · 16-Oct-2016, 04:38

Originally Posted by Steven Tribe

Where in Denmark?

Note my location!

Copenhagen

**Steven Tribe** · 16-Oct-2016, 05:11

I can have a look at it, after mutual agreement. I am 2680 - so not far away!

**Stephen Thomason** · 16-Oct-2016, 16:58

Originally Posted by jimsinar

It does stay open when I lift the lever and the lever snaps back when I release it, like there is tension on it.

Can anyone tell me if it relatively safe to open it up to have look.

Yes, take it apart and take a look. Only four screws to open it up. Clean it by flushing with denatured alcohol, holding the assembly so that the alcohol will drain off. DO NOT INVERT IT. If I remember correctly, there is a coil spring that will fall off its post and you will spend some time figuring out where it goes! Plenty of pictures on the web that will help you if it does fall off. It's not rocket science, just be careful. You will figure out how it works, why it is not working, and then you can fix it. It will take a while, but it is very doable.

You can also make your own springs if one is broken - a web search will show you how.

**Liquid Artist** · 17-Oct-2016, 22:56

Personally I would take Steve up on his generous offer. I screwed up one shutter taking it apart. Thankfully it was a spare that needed a CLA.

**Leigh** · 17-Oct-2016, 23:11

Originally Posted by Stephen Thomason

You can also make your own springs if one is broken - a web search will show you how.

Springs are some of the most complex mechanical designs in existence.

If you expect the shutter to work properly, I strongly suggest you refrain from making replacements.
Using the proper original is the only way to ensure that the shutter will function as designed.

- Leigh

**Stephen Thomason** · 18-Oct-2016, 11:17

Leigh is quite correct if the spring is used for timing. I have only wound springs that are not involved in the timing process, only in holding levers in position. Of course, they have to be somewhat close to the spring rates of the originals, but so far none have adversely affected shutter speeds.

Speaking of shutter speeds, I will report on my experience with the $20 photo diode in a four conductor mini plug used with the iPhone. It is available on eBay from a European seller: it works and is convenient. Now my o-scope feels rejected and sits mostly unused and lonely!