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View Full Version : Busch Pressman rotating back - how does the mechanism work?



Steve Goldstein
26-Nov-2008, 14:17
I picked up a pretty nice Pressman D for small money a while ago. The back rotates but is very, very stiff. I don't think this is normal as one shouldn't need three hands to turn it; in its present state the rotating-back feature is not terribly useful.

It would seem some lubrication is in order, but here's my problem. It's totally unobvious how the mechanism actually works since all the surfaces I can see during rotation are basically flat. I tried a very light film of moly grease which didn't seem to help. I assume there's something inside that really does the work, and is where the lube should go.

If I rotate the back to 45 degrees I gain access to four screws in the corners, which I guess hold things together, but I'm nervous about disassembling it in case it's massively spring-loaded - the last thing I want/need is bits and pieces flying all over.

So far I haven't found any disassembly pictures or info on the web. Has anyone ever operated on one of these and documented the process? Better yet, does someone have access to a factory assembly or service manual?

rfesk
27-Nov-2008, 03:42
You just take off those screws. Use a good quality screwdriver with a close fitting blade to avoid damaging the screws.

No springs etc to worry about.

Ernest MacMillan
27-Nov-2008, 06:48
I had one of these cameras with the same issue. Firstly, it is not a Linhof, I doubt that you will ever get a butter smooth rotating action. However, you can fiddle with the slotted adjustment of the metal pieces held by each screw as a first try- they need to be in enough to prevent wobble and out enough to allow free rotation. At the next level, a lubricant on those four pieces where they contact the back, a judicious (tiny) amount of grease of some sort. Finally, take the screws off, remove the back and inspect (You can tune it up by removing old dirt and grease with a mineral spirits soaked rag. Don't slop it around or your leatherette on the sides will peel.) For the advanced class, you can try to lap the flat surfaces on 400 or 600 grit sandpaper (wet with water) on a flat rigid surface (such as a table saw), until the mating surfaces are uniform in appearance. Reassemble with lubricant. If grease repels you there is a flat black graphite paint that used to be commercially available. Good luck, have fun.

paul08
27-Nov-2008, 09:10
My Pressman back turns very smoothly and with no slop (and I've owned a Technika III and IV (briefly)--the action of the BPD is comparable, although it feels less "damped").

To the OP: You can remove the back as described above, and you may also be able to benefit from a bit of graphite lube, but I'm afraid I can't be of too much help since mine has never had this problem. Is there a chance that something got stuck in the turning surfaces?

wkjagt
27-Nov-2008, 18:02
I had the same problem on mine. After cleaning it was fine. Rotate the back 45 degrees to reveal the four screws. These hold in place 4 pieces of metal. Take them out and you can lift the back off. You will see a large cirle on the back and the same size circle on the body. They're probably dirty. Clean them thoroughly. Not only the surface, bit in the corners as well. Any reduction in diameter by dirt will cause the back to rotate less smooth. After cleaning you can put a bit of grease on it, but I doubt if it's necessary. When putting everything back together, the position of the four metal parts can be changed to obtain a good balance between wobble/smooth and no wobble/not smooth.

Good luck!

rippo
8-Jun-2011, 11:41
Resurrecting an old thread to say thanks! A little searching before posting revealed that this issue had already been discussed. So thanks! Crud removal, and a slight repositioning of those tabs so that they don't press so hard, loosened the rotating back to where I can now use mine.

The only weird thing was that there's a spot on the back's circular lip that is degrading. It appears as if the metal is made out of two layers, and the outer, shiny layer has peeled off. I can peel more of it off with my finger! The inside is more brittle and white. This is gumming up the smooth turning, and will no doubt get worse as I use it. I put a little grease in there to perhaps delay the inevitable. Is this thing made out of aluminum? Or something else?