Inside a Compur shutter

[SalveSlog]

This is only the second Compur shutter I've been inside (the first one was a dial set Compur) so it does not surprise me that there is new things for me to see. But I can't remember having seen this in photos or videos neither.

The photo shows the spring in the retard gear train and it looks like the tension can be adjusted. I'd like to hear comments on this. Is it well known or even common?

 

[BrianShaw]

Which Compur shutter would that happen to be?

 

[SalveSlog]

It's on an Ikonta 531/2 with "F98226" on the leather. Which I've been told means from 1937(?).
It says only "Compur" on the front plate, but it has that small stiff extra spring for the highest speed. So maybe the full name is actually Compur Rapid(?).

 

[BrianShaw]

Camera Collecting and Restoration

Read this! Especially the Notes.

 

[SalveSlog]

Chris Sherlock is very helpful too!

 

[Alex Varas]

Usually I don’t touch that spring, only if I find it in the second and the shutter would benefit for a better performance but being in that position is very rare because I find it only in shutters that they never have been opened before.

 

[retina_restoration]

Do NOT attempt to adjust that spring! There are other ways to adjust the train speeds that are employed without touching that spring.