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Jim Andrada
10-Aug-2017, 22:11
I have a Grandagon 115 in Copal 1 - everything seems to be in beautiful condition except for a small problem with the shutter and Carol at Flutot's was kind enough to tell me how to fix it myself. "Minor" problem - the front element won't let go of the shutter - it's really locked on there SOLIDLY! I'm not a small person but it really won't budge at all.

Any good tricks to get it off???

B.S.Kumar
10-Aug-2017, 23:04
Does your shutter have a locking pin?
If so:
1. Mount it on a suitable board so that the pin is engaged and the shutter can't rotate.
2. Mount the lens board on your camera. This ensures that you have both hands free.
3. Use a strap wrench to rotate and loosen the front cell.

Kumar

B.S.Kumar
10-Aug-2017, 23:05
Duplicate.

Keith Pitman
11-Aug-2017, 05:59
Strap wrench (from Harbor Freight - very cheap) was the best advice I've gotten on separating lenses stuck in shutters.

mdarnton
11-Aug-2017, 06:12
Usually the front of the shutter, holding the front of the lens, and the back, are held together with only three small and long screws. I could easily see the opportunity, using something like a strap wrench, to break, or worse, rip out, those screws. Am I worrying unnecessarily?

EdSawyer
11-Aug-2017, 06:29
some heat from a heat gun may help too, go easy with it, but it's worth a try.

jnanian
11-Aug-2017, 06:29
hi jim
over the years i have heard
of putting the whole thing in the freezer
and then after it gets really cold using
a bike tire as a grip .. can't say if it works or not
but the internets ( even this website ! ) has suggested it ..

YMMV

John Kasaian
11-Aug-2017, 07:18
Usually the front of the shutter, holding the front of the lens, and the back, are held together with only three small and long screws. I could easily see the opportunity, using something like a strap wrench, to break, or worse, rip out, those screws. Am I worrying unnecessarily?
Hold onto the shutter below the front element and use the strap wrench with your other hand?

Pfsor
11-Aug-2017, 07:37
hi jim
over the years i have heard
of putting the whole thing in the freezer
and then after it gets really cold using
a bike tire as a grip ..

That would also help in the unlikely case that someone had the foolish idea to lock the lens element with crazy glue (crazy glue cracks in freezing temps). You never know...

domaz
11-Aug-2017, 09:29
I have a lens where the front element is stuck and the shutter body is somewhat "loose". The lens still work well enough so I haven't tried to force it out, my guess is if I did the entire shutter assesmbly would break or worse. Caution is the name of the game here.

Jim Andrada
11-Aug-2017, 16:30
Thanks. Carol also suggested the heat gun treatment. Maybe freeze it and heat it in the off chance that someone used something on the front element. Although why they'd use thread lock on the front ement and not on the back is a bit of a puzzle. I'll give it a try tonight.

Pfsor
11-Aug-2017, 16:34
Thanks. Carol also suggested the heat gun treatment. Maybe freeze it and heat it in the off chance that someone used something on the front element. Although why they'd use thread lock on the front ement and not on the back is a bit of a puzzle. I'll give it a try tonight.

One reason (foolish one) could be that the front element was too free and moving. You never know what the lens went through in its life.

LabRat
11-Aug-2017, 16:45
If there is a trace of thread-lok (like some blue dried goo on the outside of the threads), take a tiny amount of acetone in a hypodermic syringe and apply the smallest possible drop where the threads meet, let sit for a few minutes, repeat, and try unscrewing it... This will soften it up, and will help break the seating of the stuck threads...

Putting in the freezer has worked before... Sometimes you need to repeat it several times...

Good Luck!!!

Steve K

Greg
11-Aug-2017, 17:11
What worked for me was putting the lens in a sealed plastic bag (with low humidity inside the bag). Alternating it from 2 hours in direct sunlight, then 2 hours in the freezer. Probably repeated this 5 or 6 times over a two day period. Then let the lens come to room temperature, removed from the plastic bag, and was finally able to unscrew the front elements, all be it with a good amount of torque.

Jim Andrada
12-Aug-2017, 08:51
Froze it last night and put it out in the Tucson sun this AM and no improvement. I'll try it again and swipe my wife's hair dryer when she isn't looking. Except for the looseness in the shutter it all works quite well if I mount it upside down so gravity straightens things out. But would still like to fix it if possible.

LabRat
12-Aug-2017, 13:33
Also look very carefully if there might be a small set screw somewhere...

Steve K

Jim Andrada
12-Aug-2017, 22:08
No set screw. A couple of cycles from freezer to hair dryer and back - no improvement. I'll try a couple of more times. It's a mystery.

Jim Andrada
13-Aug-2017, 20:20
Tried a few more freezer - hair dryer cycles with no success. It feels like it's welded in place!!!

LabRat
14-Aug-2017, 01:01
Keep trying...

About the time you decide it is hopeless, that's when it will surprise you... ;-)

Steve K

Jim Andrada
14-Aug-2017, 11:15
OK - I'll give it a few more shots.

After all if I put the lens on the board "upside down" gravity fixes the problem for me. But I'd like it to be right!!!

EdSawyer
15-Aug-2017, 06:23
do you have a strap wrench or 2? those can help a lot. Difficult to apply even torque without one, and if you apply uneven torque it distorts things and ironically makes it harder to unscrew. Also, a real heat gun is much hotter and more focused than a hair dryer.

resummerfield
15-Aug-2017, 06:43
...if you apply uneven torque it distorts things and ironically makes it harder to unscrew....

I would echo the advice on the strap wrench. Or, if the front element does not protrude from the barrel, simply set the front barrel down on a rubber sheet or something with friction, and press down to increase the friction while turning. This works the best for me.

Sometimes just gripping the lens barrel with the hands distorts it (makes it into an oval) and will tend to lock the threads.

And donít forget the heat.