Sinar F2 back tilt problem, need help please!

[Marco]

Ciao a tutti!!

I have a problem with my Sinar F2 8x10”: the back tilt get jammed when I don’t use it for some times…well, I have to say that if I “force” it, and when I say “force” I mean that I have to use a very very hard force, I’m able to unjam the back tilt, and then it is fully functional until I use the camera (usually no more than a couple of hours), but when I put the camera in its case and use it after some days, the back tilt is jammed again…another thing that I noticed is that the back tilt "zero"/click stop, is not so "clear" anymore, on the front standard I feel a clear "toc", while on the back has become quite undetectable...rise/fall/shift/swing have no problems…

Well, before I take the camera to the Sinar service, which is very very expensive here in Italy (at a point that maybe is less expensive purchasing another F2 on the used market ), I’m wondering if anyone experienced the same problem, or maybe if you have any ideas or suggestions, so that I can try to repair it by myself (on the F2 the tilt mechanism seems very simple but I have no idea why this is happening)…


Thank you!!

Ciao
Marco

[Greg Lockrey]

I don't have an 8x10 but I do have a 4x5 and I can't imagine what would be hanging the back tilt at all. It's just a bolt and a tension thumb nut. Try disassembling the bolt assembly paying attention to how spacers are arranged. There must be some sort of misalignment or dirt along the bolt under the back holder.

[Marco]

Thank you Greg, I'll try to disassemble the bolt assembly as you wrote, I do think too that the problem should be there as the tilt "design" is so simple...the whole situation is quite frustrating and I'd like avoid purchasing another F2 back...is there someone who experienced the same problem?


Ciao and thank you again!

Marco

[David A. Goldfarb]

I wonder if the ball bearing from the detente has come loose (I haven't taken apart this mechanism, but usually it's a ball bearing in a tube with a spring behind it that clicks into a depression to make the stop). If it was moving around, that could cause it to jam, and would explain why the detente doesn't work. I suppose that if something were stuck in the detente, that could cause problems as well.

[Marco]

I wonder if the ball bearing from the detente has come loose (I haven't taken apart this mechanism, but usually it's a ball bearing in a tube with a spring behind it that clicks into a depression to make the stop). If it was moving around, that could cause it to jam, and would explain why the detente doesn't work. I suppose that if something were stuck in the detente, that could cause problems as well.

mmmhhhhhhhhh David, that sounds interesting!!...in fact I noticed the ball you are referring to, and I thought "ok, this is the click stop" , but since I had no idea how it works I didn't connect it to the jamming problem, but actually your words open up a new series of possibilities...another option could be that, after years of use (I bought the Sinar second hand), the depression has become too "deep", and the ball get stuck into it: does it make sense in your opinion?...and do you think that it would be difficult to take apart this mechanism? (I'm not very good with manual operations )...


Thank you!!!


Ciao
Marco

[David A. Goldfarb]

It could be, although I had an older Sinar F that never developed this problem, so I would be surprised if it's possible to wear a deeper depression into the mechanism. If you're careful and deliberate about it, keep track of the screws and take digital photos as you go, I suspect it shouldn't be too hard to take apart and reassemble. I've worked on my Sinar P rear standard, which is more complex than an F/1/2 rear standard, and it didn't seem too mysterious. Given what it costs for Sinar to make the repair, it's worth figuring out how to do it yourself, and ordering any replacement parts from Sinar as needed. The parts most likely to need replacement are rubber cushioning strips and pads, nylon gear tracks, and dry bubble levels.

[Marco]

Ok, thank you for the advices, I'll try to take apart the mechanism and keep track of the screws...and I will keep my fingers crossed!! ...


Ciao
Marco

[Greg Lockrey]

I managed to break that retaining screw that holds the thumb lever to the bolt. I'd oil that first. I lucked out and a guy on this forum happened to have one for sale.