View Full Version : Unicum shutter

6-May-2017, 22:27
I'm trying to repair this Unicum shutter


but I don't understand how it works

may be some part are missing?

if some of you have a diagram of this model please let me know


7-May-2017, 12:00
The left piston attaches to your rubber tubing and bulb and actuates the shutter. The right piston provides resistance to the shutter closing and regulates how long the shutter remains open. There are videos on operating and repairing out there: https://youtu.be/F0Ha5ViYlo8

7-May-2017, 23:50
Thanks seezee,

problem is that it is the first time that I see this version, with leaves working horizontally,

the pin (1) has to move the lever (2) in order to open the leaves: but I don't know how to keep the lever in the right position to do it

may be some part is missing?

I'd like to ask to any of you that have a shutter of the same model to retire the rear cover and take a picture with the detail of the mechanism

thanks in advance!

8-May-2017, 00:07
The one comment I will add is to avoid any moisture, solvents, or lubes anywhere near the shutter blades or iris, as they were paper, rubber, and other (very old) materials that can be ruined by the above...

Usually sticky, dried grease in the speed escarpment will trip up the speeds on these...

Oh, and you should be very carefully photographing the disassembly of any shutter you decide to mess with, so you have a record of parts location, etc, so you don't have to ask online where something goes on your shutter... (Use a point & shoot camera with a good macro setting, and put a piece of white tape or a piece of white plastic bag over the flash to balance the brightness up very close, and provide an almost on-axis lighting with acceptable shadows... And you can blow these up on a monitor, or make hard copy for reference...)

Good luck,

Steve K

8-May-2017, 00:29
thanks Steve,

I always take photos and notes when I open a shutter, camera or lens for first time.

In this case, the shutter was in not working condition. My doubt is if somebody opened it before, and, if so, if some part was missing.


Steven Tribe
8-May-2017, 05:03
I'll join this thread in a few days as I have a Unicum shutter which needs work on it too.

Mine is part of Busch casket set (Aplanat - not the Vademacum) and I must admit that I have thought more about getting hold of a later shutter with the same threads and distance rather than attempting to do a repair! This is because I didn't like the look of the mechanism when I opened it up years ago!

8-May-2017, 06:13
I have one of these that I did minor work on many years ago, and it does still work... It does open and close evenly, and the speeds do operate, so there is a good chance that one could be restored... I think that one thing that helps these is that the mainspring is a fairly strong force, so it keeps things moving along...

I think I had to clean under the speed dial mechanism as that was gummed up, but I think I remember was that there wasn't too much else inside, and it could run without much (if any) lube inside once clean... The timing piston/cylinder can be cleaned/polished and checked for smooth movement...

Not a great shutter, but not all that bad (compared to other offerings from the period)...

Steve K

Steven Tribe
9-May-2017, 04:33
Had some time to-day!

There is a spring missing!

Your last photo has a lever, numbered 2. This has a mounting for a spring at the top which should be attach up to the dial - in very much the same way as at position number 1. Except it is on the opposite side! I can't see whether they are the same spring or whether two springs end at position 1!

The photo is my equivalent of your last photo.

10-May-2017, 00:35

your information has been very useful

many thanks!


Steven Tribe
10-May-2017, 02:23
OK, so there is just one spring around the dial, which had become detached at one end! Thanks for the good photos which will help me when I reassemble mine.