View Full Version : Can't remove rear cell from old "rapax" shutter

10-Sep-2010, 13:52
I think I covered it mostly in the title. I want to clean some shutter grease off an old lens I have. I managed to remove the lens from the lenboard and the front cell no problem...but the rear cell seems to be stuck, possibly threaded into the shutter. Is this common with old lenses? Do I have to remove the entire rear lens assembly to get at the shutter blades?

Here's the shutter in question:



10-Sep-2010, 14:29
It should screw out. Maybe someone loctited the threads or something horrible. Try using a rubber tool to grip the lens and unscrew it and hope for the best.

John Schneider
10-Sep-2010, 14:39
Use a strap wrench on the rear cell. If it's really tight, spray some Liquid Wrench into the threads and put it into a warm (~150F) oven for an hour or so, then go at it again with two strap wrenches.

10-Sep-2010, 14:45
Wow, thanks. I can't believe I got a response to such a specific question so fast. I will try just that.

It does seem possible that someone did terrible things to this lens, though; there's so much grease the metal has grease stains and there's a hair in the shutter, too.

I assume it's okay to replace it with a newer lens for the time being, even though the lensboard seems to have a hole slightly larger than the copal 0 in my new lens? I'm new to this, if you hadn't noticed by the post count. Anyhow, thanks again.

10-Sep-2010, 14:48
Unfortunately the rear cell only has about a millimeter to latch onto in this weird shutter design, so my strap wrench isn't doing it. Will wd-40 help? Don't own any liquid wrench. I'll post a photo just to make sure nothing is weird with this. It's a lens for a polaroid 110 camera or something?

10-Sep-2010, 15:07
Using a slightly larger hole than your lens is usually not a problem. In a pinch I've used a large retaining ring and actually put a #0 shutter into a #1 board, then I put a bunch of black tape on the back to block any possible light leaks. Worked just fine.

Food for thought- is it really necessary to remove the rear cell? As long as your are careful with your cleaning you might be able to clean the shutter up without removing it. In most shutters the only time you need to get to the rear of them is to service the blades. Servicing the blades is a tricky business and they tend to fall out everywhere when you undo the back cover.

Dan Fromm
10-Sep-2010, 15:18
Policar, try pressing the back of the lens into a car tire and twisting the shutter. This sounds odd but its an old trick that I've used on several lenses.

10-Sep-2010, 15:46
Policar, try pressing the back of the lens into a car tire and twisting the shutter. This sounds odd but its an old trick that I've used on several lenses.

I do something similar. A sheet of rubber on a table works well.

10-Sep-2010, 20:09
Even that didn't work but it's a great idea. Going to try something else later, but for now my new replacement lens is in the board so I'm happy. Thanks again for all the help.

11-Sep-2010, 20:53
So I got the rear cell off and the shutter all nice and clean and the shutter seemed close to accurate...

But then I took it apart a little more and I think I cocked the shutter while the front cover was off and and now the shutter won't fire...

Gah I am so bad at this.