Binocular Repairs

Without a picture of how the lenses are assembled, I'm not sure why you would want to remove the retaining rings. You can clean the outside lens surfaces without disassembling the lenses. If the inner surfaces have gotten dirty, most binoculars I've owned allow you to remove (unscrew) the lens cells as whole units to clean the inside surfaces. [Are these not like that?] You might need to unscrew the lens barrels from the central prism section, then use long swabs to clean the inner surfaces.

Separating an achromat lens set is usually only necessary if a contaminant has somehow gotten in between the lenses. If you don't get the lenses aligned properly and get the cell gap correct when you re-assemble them, the lens assembly can give you chromatic aberration.

If you can post a photo it might help.

The dirt appears to be on the inside of the objectives. I dont think it is between the individual lenses. I would not want to disassemble down that far either. There are no unscrewable barrels. The entire body is one single casting. Thats why I think somebody tried what you said using VERY long swabs all the way from the other end where the back plate can be removed to gain access to the prisms. I cant seem to loosen the lens cell as you suggested. I´ll try to send you a foto.

Thanks

John

Use the classic mechanic's trick.

Cool the lens assembly and heat the tube.

Maybe an ice cube and a heat gun?

Interesting suggestion. It might work as long as I dont get the lens assembly wet.

Thanks

John

Take a look at the thermal expansion properties of the metals of construction and do the math. Do the math on the glass too.

I think you are capable of performing this if you choose to try it.

The difficulty of shipping into and out of this country are also an additional motive so I think I might try it. Without doing too much math I´m sure the body, made of aluminum, and the glass lens have considerably different expansion coeeficients as you suggest so maybe a very cold damp cloth on the lens part and a hot cloth on the body would work. What I need is a copper clampping wrench with a diameter of 3.54 inches to grab the outer body of the lens cell without marring it. I searched a lot but can only find these wrenches in smaller sizes. Maybe an oil filter wrench might work. I do not want to cause any damage to these beautiful babys.

We were hoping to use these glasses to view Comet Garradd this weekend from a dark mountainous area towards the center of the island about 1000 meters above sea level so I think I will try the disassembly when we come back.

Thanks for all your input. I will let you know how it works out.

Regards

John

It sounds as though you could use a strap wrench like the type used to remove oil filters. Sears sells a plastic strap wrench that is non-marring.

If you check around, you might be able to find someone who has a Vortex Cooler. They are made by companies like VorTec and ExAir. They use compressed air as an input, and output cold air at one port and hot air at the other. With some flexible tubing, you could direct the two streams to the appropriate places, or just point the cold air port at the lens and use a heat gun on the barrel.

Machinists sometimes use them to cool cutters where they don't want contamination of a part by liquid coolants. The ones I've used are noisy and use a lot of compressed air, but they do work. I see them advertised for cabinet cooling, which tells me they must have found ways to make them quieter.

I'll ask/suggest the obvious -- have you checked with Nikon? They might not formally offer disassembly/repair instructions to "unauthorized" technicians, but a call to tech support, or engineering may find you a helpful "authorized" tech/engineer.

Yes, I sent them a request for information and am now waiting to see what happens. Most large companies like Nikon dont usually respond to little questions very well. I was hoping one of you guys might have had an experience with this very same model.

Thanks

John

This is a source for the shop manuals and a support site....

http://www.fixya.com/support/nikon/binoculars

After some further research, these are worth at least $800, any advice I could get was to get them factory serviced....est $65 + $20 for realignment + shipping

yes you are probably right.

I have been able to do some pretty complicated fixes in the past successfully and so all my freinds bring me thier things first for my opinion. In this country we still fix a lot of things that others up north throw away.

But I think you are right on this one since they are still quite usable as is it would be a shame to damage them.

John

Thanks

There is a large Internet community of optical enthusiasts at the web site called Cloudy Nights. Many are professionals and there is a dedicated section devoted exclusively to Binoculars section of the Forum.

Membership is free.

Here is the link directly past the home page to the Binocular Group.

http://www.cloudynights.com/ubbthreads/postlist.php/Cat/0/Board/binoculars

Should you choose to join so you can post questions, return to the home page and simply apply. They are a generous group. You'll get lots of experienced help.

Laughing Jaguar

If you do ship them out to a Nikon Service Center make sure you have enough shipping insurance to cover their replacement because of theft, loss and damages! At $800 USD those are very expensive binoculars indeed!

Good luck with them!!!!!

Chances are the objective lens retaining rings are sealed. Kern and Zeiss military binocs use a tar like substance which is softened through ultrasonic immersion in freon. Applying heat also works in certain conditions but I would highly advise against it.

To properly apply nitrogen it's advisable to use a vacuum chamber capable of -10 atmospheres.