Grundner Shutter Repair/Servicing

[cyberjunkie]

I didn't open mine. I think i'll do it as soon as i'm done with more urgent stuff...
I don't understand if the original bellows inside the "actuator" was linear (i.e. cylinder-shaped) or pleated (like camera bellows). A pleated design would allow for easier extension, but i guess it would take more room when compressed.
BTW, which glue did you use to attach the cycle tube to the metal parts?
I guess that you prepared the parts with little sanding and de-greasing with some solvent, isn't it?
If the cement you used didn't fail under pressure (once completely cured), i think i will copycat your solution

well done

have fun

CJ

[Steven Tribe]

You can see the solution in an earlier posting. You have to check the minimum and optimum position of the new bellows to counterbalance the permanent long weak spring (usually in fairly good condition).
Steps are:
1. Cut inner tube to the required length (expanded length plus twice times 1/2" for overlap at the end disks.
2. Cut out two end discs (ca. 30mm in diameter). Drill a hole 1mm wider than the hose you have selected.
3. Make a grove about 5mm from the end of this hose. About 0.5mm deep with a triangular file edge.
4. Mount the two end discs on the cut inner tube. An overlap of a 1/2" should make a stable construction.
5. Heat the rubber/disc assembly in a domestic oven (when you partner is absent as it smells) to about 180 deg C for approximately 15 mins.
6. Allow the turkey - sorry - cylinder to cool before taking it out of the oven.
7. This process collapses and forms the rubber to some extent which allows glueing without the rubber slipping off the discs.
8. Lift the edge and insert contact glue right down to the rim. Place under a 5 kilo weight to maintain pressure for hours. That is, don't rely on the instructions on the tube of glue!
9. Wait 24hours before inserting the rubber hose and testing.

[europanorama]

They open on applied pressure and collapse on release. Best for seconds but can function done to 1/10s of a second.
Will search Mcmaster again.

i measured about 1/7 sec. both with button and handle. 12 or 14cm diameter. bellows was terribly damaged. repaired with ultrathin 3M 850 F opaque tape. since no repair-pro its now looking unprofessionally made but lighttight.
On FB Largeformatphotography or similar i once posted a video shutter-action with unrepaired version.