Lubing pronto shutters (and maybe others)
While I don't claim to be an expert at this,
I am mechanically inclined and have cleaned and lubed several of these
old shutters and got them working like new. The problem is the grease congeals
and makes the gear train "sticky". I've never had to lube shutter blades
or any other parts.. Also have gotten self timer working applying the same
techniques. Well here's how:
First you have to remove
the front element. Most of the lenses I have fixed have a screw in stop
in the side of the front element that limits rotation. Remove this screw.
Now turn element clockwise until it stops and note position of screw hole
so you can make sure you reinstall front element correctly. Now unscrew
front element and put aside. Now remove the two screws that hold down the
cover plate and note position of each as there is a long one and a short
one. Remove the cover plate but don't remove anything else.. This is as
far as we need to disassemble it. Now it's time to clean and lube.
We want to first get
our supplies together. I use automotive carburetor cleaner (spray kind)
and very light machine oil. Also a couple of toothpicks are also needed.
First spray some carb cleaner into a cup. Do not spray into shutter. Them
dip the end of a toothpick into the cup of cleaner and get a small drop
on it. Then apply the cleaner to the visible ends of the gear shafts and
the edge of the fastest spinning timing gear and one (any other) drive
gear and operate shutter several time.. first at high speeds (the ones
that usually still will work) and the go into the slower ones. Some times
you need to apply the cleaner a couple of times.. I work the cleaner in
at all speeds and also work it into the self timer gear train.. Once the
shutter is free, I them apply the machine oil *VERY* sparingly to the shaft
ends and the edge of the fast spinning timer gear. Also to the edge on
one or two drive gears and it will work it's way onto the other gears..
Then let it sit awhile (good time to clean all the lens elements) and check
to see it still works nice after sitting. I also remove rear element and
set shutter on B, hold it open and clean back of second element. All we
need to do now is replace cover plate, front element (making sure it stops
when fully screwed in in the same place as when we started) and reinstall
stop. Now you have a clean lens and a smooth shutter that will work great
again! Hope this helps you fix yours..