Sinar Norma Problem

[William Whitaker]

I was working with the 8x10 Norma today when the rear focus began to bind and became difficult to turn. Prior to this it has been easy to operate. So I pulled off the rear standard and disassembled the dovetail focusing slide. I expected to find sheared off metal filings, but fortunately did not. What I did find was that the binding was not between the pinion and the rack, but in the pinion axle itself. That is, even now that the pinion is not engaged to the rack, the focusing knob is still difficult to turn. Yes, the lock is off.

Either something has gotten into the mechanism to cause binding or somehow the mechanism has tightened up. There is a collar located between the focusing lock and the bottom slide assembly which holds the pinion drive together and probably provides for some adjustment. But it apparently requires a dedicated spanner wrench which I don't have. And very likely further disassembly is beyond my expertise.

Does anybody have any suggestions? Are there any recommendations for an experienced repair shop for Normas?

[Richard Wasserman]

http://www.precisioncameraworks.com/Pages/about.html

Bob Watkins has worked on my Norma and is very experienced—factory trained, I believe.

[Frank Petronio]

Ditto, he worked for Sinar before Arca.

[Stephane]

Last xmas by the sea, the whole norma started to be stuck, and when turning the mechanism it was getting so stiff I got scared to break it when focusing.

When to a mechanic shop, got some WD40 equivalent. WD40 takes away rust, lubricate and prevent water to come back. Just spray almost nothing and it will be as good as new!

[Frank Petronio]

hahaha

[rdenney]

Last xmas by the sea, the whole norma started to be stuck, and when turning the mechanism it was getting so stiff I got scared to break it when focusing.

When to a mechanic shop, got some WD40 equivalent. WD40 takes away rust, lubricate and prevent water to come back. Just spray almost nothing and it will be as good as new!

WD40 is not a lubricant. It is a solvent. It works by dissolving existing grease, but when it evaporates, the grease will harden again (if any of it is left). It will get you through the day, and perhaps last for a few months, but it will not restore the camera for another 40 years of problem-free use.

Remember, grease is just oil emulsified with soap. When the oil evaporates out, the soap is left, which will dry out and bind parts. WD40 will dissolve the soap to some extent, but it will not turn it back into grease.

You might as well use naptha (lighter fluid) and dissolve away the grease on purpose. But then you have to replace the grease, and often that requires disassembly. An alternative is to dissolve the soap with a true lubricant that includes something like an alcohol to dissolve the soap. An example of that is Kroil. But it is too light to replace applications requiring heavier grease.

Rick "on an eternal quest to prevent the use of DubbemDeeForty as a lubricant" Denney

[R Miller]

Certainly agree that the use of a "proper" lubricant in any mechanical device requiring a lubricant is advisable, and that WD-40 is not a suitable replacement for any application requiring a grease. However, based on experience and that, if one believes Wikipedia, it contains about 15% mineral oil, I disagree with the blanket statement that "WD-40 is not a lubricant" - although I do understand, and can appreciate, the "quest"

http://en.wikipedia.org/wiki/WD-40

[Stephane]

WD40 will sort you out, this is not soapy water. I tried, and it works.

If you are all too scared to spray a bit, go pay someone else who will do it in your back.

[rdenney]

WD40 will sort you out, this is not soapy water. I tried, and it works.

If you are all too scared to spray a bit, go pay someone else who will do it in your back.

Oh, it will work...for a while.

But what oil that is in it is so light that it will not provide much film strength, and the parts will wear at a high rate.

I once collected old clocks, and have seen the effects of WD40, which has a highly distinctive smell. That smell routinely doubles the quoted price for clock repairs, and there is a reason for that. That in addition to what I know about lubricants as a result of my engineering experience.

Argue if you want.

Rick "thinking a Norma deserves a proper long-term repair" Denney

[rdenney]

Certainly agree that the use of a "proper" lubricant in any mechanical device requiring a lubricant is advisable, and that WD-40 is not a suitable replacement for any application requiring a grease. However, based on experience and that, if one believes Wikipedia, it contains about 15% mineral oil, I disagree with the blanket statement that "WD-40 is not a lubricant" - although I do understand, and can appreciate, the "quest"

http://en.wikipedia.org/wiki/WD-40

I can't quite resolve the U.S. MSDS sheet claiming that much of it is hexane solvent, and the German safety sheet claiming that much of it is naptha. These are solvents, and the machine oil is soluble in these solvents. The film it leaves behind is not intended as a high-film-strength lubricant, but rather a corrosion-resistant coating.

Kroil, on the other hand, has a much smaller percentage of alcohol as a solvent, and a heavier machine mineral oil intended for film-strength applications.

Even lighter-fluid has oil mixed with the naptha, and machines doused in it will run beautifully until it evaporates. Nobody would call it a lubricant, however.

Rick "eschewing quick fixes" Denney