I think the prism assemblies have come loose and are rattling around inside.
Is it a repair I could make?
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I think the prism assemblies have come loose and are rattling around inside.
Is it a repair I could make?
The real problem is that you could get inside and tighten the prism - or whatever it is that is loose but once you have done it, they will need collimating. And THAT is the difficult thing to do with L11's and 12's. That's because in those, you have to use multiple eccentric rings to collimate two separate prismatic telescopes whereas with the old No2's and 5's you rotate a simple(?) prism on one or both and this prism is the actual objective lens. The L12 binos have a special collimator........
I think that I might have the parts list so you can see your way. But don't hold your breath.........
Does this model of binocular have a bonded prism and if so is it not likely that that adhesive has failed? A few years ago I paid an "expert" to refurbish a pair of Barr & Stroud 7x50 Naval binoculars for me but I regretted it because they came back with one side showing spotted vision. When I complained about this I was told that special jigs were required to re-glue the prism which were no longer available and so I would have to accept it as it is.
Thank you, Peter. Obviously not something I can do then.Quote:
Originally Posted by Peter Laidler
They worked for 37 years. That’s a good run in my book.
I have been reading and that is probably the case.Quote:
Originally Posted by Flying10uk
The good news is I found a pair for sale and they are on the way.
I would still really like to have these repaired if it’s possible.
Nope, the bonded prism was the preserve of the No5 7x 50 binos. There was a jig to replace the lens onto the prism but if your repairer had simply looked at the other side and judged the positioning reasonably accurately using balsam instead of UV fix, then any small discrepancy could have been rectified using the prismatic OG lenses. UV fix means that the lens is stuck to the prism for good...... fault an' all!
Nope, can't find a parts list for the old L11 and 12 binos but did find others. But internally they're not complicated. In fact they're really two slimmed down SUIT or SUSAT sights joined together
Thanks for looking Peter.
You said they are like two sights joined together. Does that mean I can replace the left side with the left side from another pair?
Yep. While the sides are handed the internals are identical except for the graticle pattern cemented within the field lens. Just beware of that if you're dealing with L12's. L11's are opbserving binos as opposed to spotting binos so they don't have a graticle
Thanks Peter. I will give it a try.
You could just ask Alvis Motors (the AVIMO part) based in Somerset somewhere if they'll fix them.
A jig can be made very easy and doesn't have to be a tool room example, although not for a Barr & Stroud the pic should give an idea, as Peter said using balsam you can redo till the cows come home.......Quote:
Originally Posted by Flying10uk
A very simple jig below, Heath Robinson yes but does the job....
https://www.milsurps.com/images/impo...705tjawk-1.jpg
A link below is a repair to Binocular Prismatic No5 may be of interest to some, includes the home made Jig above.
https://www.milsurps.com/showthread.php?t=53576
Thanks for that bigduke. After my experience of paying an "expert" to repair a pair of binoculars for me a few years ago I have started doing my own optic repairs to my binoculars but not for other people's binos. I remembered back to what my foreman told me when I first started work- "If you want a job doing properly do it yourself." My repairs have been reasonably successful on a number of mainly ex military binos but the tricky job is always if a prism requires bonding back together. When I have done this I use a type of pattern Super Glue available on-line which certainly bonds the parts together. The thing is that using this glue you really only get a single chance of getting it right and at the same time you have to watch that you don't bond the prism to yourself. I have just glued the prism together freehand with-out using a jig and estimated the correct position; obviously using a jig would result in a better quality of job.
Another bit of useless info........ In 1965, if you lost, misused or damaged a pair of No5 binos it'd cost you £35. The prism assembly would cost you £8 if you damaged one. Don't know how the average Joe would damage one unless he dropped it, but there you go! The last time I knew of a pair going missing was about 8 years ago and it was going to cost the unfortunate PCD student £250. So just before the 'system' started to roll I suggested that he buy a gash pair on Ebay for a few££ and leave them on my desk following which he take a selection of tea,coffee and biscuits to 'Jock' Pxxxxxxxx the Instrument Sgt......... Anyway. All's well that ends well as they say
Is the MOD still using WW2 dated No2 & No5 binoculars and do they still keep them in reserve/storage? The reason that I ask is that I'm currently reading a most interesting book called Sniper One, by Sgt Dan Mills and is the true story of a British sniper team fighting in Iraq 2004. They use the bolt action L96 sniper rifle as their weapon of choice. In the book it briefly mentions that the British snipers still use WW2 dated sniper's periscopes because they were the best sniper's periscopes ever made but it doesn't give any further information or photograph. The obvious explanation for a need of a periscope is so that the sniper doesn't have to stick their head up in view of an enemy.
I have to say that I never heard of periscopes being used in anything other than AFV's - and an AFV periscope would be useless to a sniper as they were set into an armoured housing!. We certainly were still using No2 and 5 binos in both Gulf wars and you'd occasionally see a pair or No2's hanging around someones neck in Afghanistan. Sniper periscopes............ Never saw anything like it in my time. I'd call that into question. But I could be wrong of course.........
Hi Peter,
I was offered loads of them recently with new telescopes as an aside which I sold easily.
Sadly there are no more spares available they told me to try German Rollei Company who may have some alternative bits and pieces.
The bino from experience was always susceptible to operational knocks which it didn't like or a severe blow which would throw off collimation, and in a lot of cases made re-collimation impossible as the prism assembly shifted. That was my experience and most of the ones I picked up had a defect or other.
Rollei would be my port of call if you really want to progress a repair, unless Peter wants to have a look.
Like a lot of NATO kit, when its new and working in the right operational circumstances its magic, when it lets you down when you need it most very frustrating.
Ironically to keep to your answer Peter, the best tank periscope I have is an old Sherman tank one its brilliant and survived the test of time.
Gil
I'm suprised that there's no more avimo spares. They were still being serviced a couple of years ago but no more new ones. I still use an old set of No2 Mk2's........
Peter,
There probably are if you know what I mean, in a large crate at Withams awaiting an auction and few people know what the NSN stands for :banghead:
Quote:
Originally Posted by Flying10uk
I think it might have been an old Soviet TR type periscope, like the one in this picture.
https://www.milsurps.com/images/impo...16/06/TR-1.jpg
The picture looks very slightly familiar, Vincent, but I never would have guessed that the stick thing up against the wall was actually a periscope.
There’s more about them here. Soviet prewar and war time trench periscopes
The L12 binos I ordered arrived.
https://www.milsurps.com/images/impo...06/L12A1-1.jpg
They are in much better condition than my old pair.
Thank you, Peter for all your help. Logic tells me these will work fine and I am happy with them. I will keep my old pair for parts if needed.