Monarch 5 eyecup failure (1 Viewer)

Hi,

Fortunately it happened during my last day in the Straits/La Janda/Los Lances, but my eyecups (both, surprisingly) got very stiff. One of them was so heavily stuck, it unscrewed when I tried to deploy it.

I was operating the eyecups a lot, sometimes using the binoculars with sunglasses, sometimes without them.

I could manage to deploy it and screw it in place, and today I am checking the damage, which is curious.

I have disassembled the whole eyecup, and I see no obvious reason to become so stiff. I see no erosion pattern on the plastic pieces, so my best guess is that the tiny rubber inserts (which should be ball bearings) just dried out. For the record, we had a lot of strong wind.

Some vaseline grease (the same I use for the aquarium peristaltic pumps) has made the trick. I've lubed the tiny inserts and the eyecups are operational again. Even better than before.

I guess this maintenance will become a sort of periodic thing, maybe every year or two, we will see.

I was considering contacting Nikon service to buy new parts, but Nikon in Spain is an absolute disgrace. And I don't see a parts store for Spain. If it happens again and there is some obvious tear I will maybe try to contact Nikon UK by proxy (I have friends in London).

Instructions for cup disassembly are here:
http://blog.naturespic.com/2014/08/15/nikon-monarch-atb-binocular-broken-eye-cup-replacement.html

Be very careful with the rollers and the tiny screws. I used a PH000 Philips screwdriver and removing them required some experience.

Just an update. Vaseline grease turned out to be inadequate as a lubricant. It tends to get stuck if I leave the binoculars alone for several days.

Finally I have used a silicone based lubricant and the result is much better.

A quick update. It's been 5 years and although I haven't used them much this year (I got a pair of Monarch HGs) the eyecups still work perfectly with the lubrication. I haven't reapplied anything.