Removing Old Linhof (stuck) Front Cell

[gary_deal]

Got an old Linhof Symmar 210 on ebay, circa 1963, looks very nice but the shutter was real sticky. I've cleaned out those

old compurs before, but this one wouldn't let go of the front cell. The rear cell was snug, but the front cell won't budge at all,

in either direction.

 

Now, having seen some overkill on the part of Linhof engineering, and not having had this particular configuration of

shutter before (black anodized dress ring on the front that seems to be slightly "sprung" from behind, with "LINHOF" engraved

on it as well as the dual aperture scale, shutter goes to 1/400), I'm wondering if those Linhof engineers added some "feature"

that's keeping the front cell from unscrewing.

 

Is there some trick for getting that front cell off? Does the black dress ring need to be pushed down (really hard), is there

a hidden set screw somewhere, or did some previous fool put threadlocker in there?

[michael_briggs2]

I have a different lens in a Linhof labeled Compur shutter. At least on that shutter, the black ring labeled "Linhof" is just a decoration. It doesn't retain the front cell in any way. The front cell screws into the shutter just as it does on a non-Linhof-decorated Compur shutter. All I can suggest is to use as much torque as seems reasonable, possibly using a rubber sheet to grip the front cell.

[lee hamiel]

Gary:

 

You may want to try strap wrenches - see: http://www.photo.net/photo/3781682

 

This is a drawing I had done for another purpose so you will want to reverse the two wrenches & directions.

[paul_ewins]

To amplify on Michael's response, I used that technique last night to budge the front cell of a barrel mounted G-Claron. Put the sheet of rubber on a sturdy surface (i.e. table or work bench) Place the lens face down on the rubber, assuming that the front element is recessed enough so that the glass doesn't touch the rubber. Now grab the shutter, bear down with a fair amount of weight and then twist to unscrew the cell. Once the cell starts to unscrew stop and try unscrewing it normally.

 

If the front element protrudes past the cell mount then you'll need to try a strap wrench around the edge of the cell.

[michael_crowell2]

I once had a very stubborn dirty lens cell that wouldn't budge. In frustration, I placed a tiny amount of ordinary isopropyl rubbing alcohol where the cell threaded in (the end of a toothpick is a good applicator). The solvent effects immediately broke the cell loose. Obviously, this might not be appropriate near a shutter, but if it's just metal and glass you're dealing with, it should be safe enough.

[kelly_flanigan1]

There is alot of surface area where the threads are. Any tad of corrosion adds to the problem with unscrewing a lens cell. Being in a hurry will make the threads tighter. With some Katrina dunked in salt water lenses, most all are locked solid, except one I lubbed in the 1960's with Texaco waterproof outboard motor grease! A brass cell is way more robust than aluminum with salt corrosion in lens cell threads. Many brass cells I have been able to remove, but very few aluminum ones. Here I have used the teflon type nut buster type products. Even with the best hundred dollar lens spanners, some cells can be difficult. A dented ring should be checked for too. Heat/cold cycles sometimes help break free the stubborn threads too. Hidden setscrews are sometimes used alot with military lenses, often covered up with black paint. If you find one the other(s) are many times 120 or 180 degrees away. Some lenses are actually bonded, ie the lens threads tacked in place too. <BR><BR>A smaller diameter screw or lens cell often will be stuck worse, there is more surface area to the diameter ; as screw threads drop in size. When a screw drops in diameter by two; the cross section drops by four of the screw, but the thread surface area drops by two. Thus it is real easy to ruin a dinky 0.5mm screw; compared to a say 1mm screw. Threadlockers are made less aggressive for smaller screws for this reason.<BR><BR>