Help with No32 Mk3 scope setting focus

[Frank LE]

I have a small problem with my indian No4(T) with the No32 Mk3 scope. I have been at the range today for the first time for zeroing this rifle. Firing at 100yd the group was in 2.5x2.5 inch. For me a good result.
So far so good!
The only thing is that the scope is a little bit out of focus, so that the post is not sharp for my eyes.
What to do now? I looked in Capt Laidler´s books about the No32 scope and No4(T) and did not find an answer.
Is there a way to set the focus, or do I have to live with that?

Can anybody out in forumland help?

Regards
Frank

Information

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[Peter Laidler]

Here's what I need to know first Frank. Was it in focus when you first fired it? Mount the rifle securely so that you can see a distant aiming point (a DAP) at infinity

Just behind the range turret you'll find a collar and set into this collar you'll find a cover plate held down with four (or two on the later ones) round head screws. Unscrew these screws and lift off the cover. Underneath that, you'll find a brass or sintered alloy locking segment with a little hole in the middle. I want you to lift this locking segment out. Underneath this......, phew......, you'll see the outer sleeve of the erector cell

You'll see that underneath the locking segment is 'threaded' or saw-toothed. And if you look even more carefully, you'll soon realise that it can be put back front to back or back to front. In other words, it's symmetrical........... but it's symmetrical in that by putting it in front to back or back to front, it will give a half pitch of adjustment. Clever isn't it.......... and not a lot of people know about this.

Looking through the CENTRE LINE of the telescope at the DAP, gently move the erector cell forwards or backwards..... a smidgin at a time. Now DO NOT stare through the telescope as you're doing this. but just glance as you're doing it. When the graticle and the image (or DAP or target, because don't forget that you are actually looking at an image now.....). When the grat is focussed exactly for you, you can lock it up.

Look carefully at the splines of the erector cell and the locking segment and judge the best position that the splines of the locking segment will hold the erector cell in that exact position. Put a blob of grease onto the segment and place it into the hole. Replace the cover and that's it.

NOW move your eye slightly to the left and right. The point of the grat should remain fixed onto the same point which indicates that the graticle is falling on the same focal plane of the image and there is no parallax. That is the simple answer................

Underneath that

[Frank LE]

Thank´s Peter for the quick and complete answer.
First: The scope was out of focus when I got the rifle. I noticed the focus offset, but until the range test I thought it will be no problem, it is just a little bit unsharp.
I will do the setting on Monday and will report the result.

Have a nice weekend!

Frank

[Frank LE]

Today I tried to focus my scope and after removing the cover I found that one of the owners before me damaged the little hole in the locking segment, so that I cannot pull it out without any further damage. The segment is sitting extremly tight and the hole is completly worked out.
For the moment I stopped the work and will live with the little unsharp focus.
When I am concentrated it is no problem at the range.

Thanks for the help
Regards from Austria

[Frank LE]

I tried to live with the unsharp focus but at a range of 300 yd and over it is very hard to shoot.
So what to do now?
Are there any locking segments as sparepart anywehere?

When I send the scope to Fultons in the UK can they replace the locking segment?
I dont want to force out the segment of my scope because I think I will destroy the erector cell, so this should be done by an expert.
Can anybody who has expierience with repairs done by Fultons give me some info.

Thanks
Frank

[Peter Laidler]

Speaking from experience, if you send your telescope to Fultons, it will come back to you in Base Workshop/Factory Repaired A1 serviceable condition. That is not like a new car, but it will be like a restored car and ready to give you another 60+ years of good service. So far as I am aware, small parts such as the locking segment are available so do not worry about these Frank

[kryten]

Hi Peter, Sorry to hijack the thread. First off, is it possible to get the graticule repaired ? I have a Mk1, but both the post and crosswire were missing. I have performed a repair of sorts, by using a short length of 1 amp fuse wire and it is not too bad. I can actually use the scope.

I have cleaned the eyepiece lenses and objective lenses, but could not remove the erector cell. When I removed the locking segment, the cell seems to be solidly in the tube. So I left it alone.
I like this old scope and it always draws a crowd when I use it on the range. I would like to get it serviced/repaired. The elevation screw threads are not the best. I managed to cleaned them up quite well and the elevation works, but a fair bit of backlash. I am using it on my Longbranch on a SK mount ( I know sacralidge ) . I am based in Ireland, so I persume Fulton's would be my best bet.
Cheers for now,
Alan

[Peter Laidler]

You can't actually repair a grat or crosswire unless you know a magician. All you can do is turn a new grat and replace it with the crosswire. Taking a scope apart that is stuck fast with that old 1940's bitumen that's set like concrete is a bit of a problem. Both chemicals and heat can destroy the optical bond. Sometimes it takes just good old brute force and ignorance. But you have to know NOT to go beyond the point of no return.

There are other scope repairers in Australia and Canada as well as one in darkest Wales. But the grey haired old boy who does them for Fultons seems to know what he's doing - some of the time although he tells me that he doesn’t actually enjoy it, but he’d rather see them being used than left on the shelf!

The problem now is spare parts. Gone are the days of the parts for L1A1 and Mk3 plus a lot of those for the Mk2/1 and L1A2 being available through ‘the system’. For example, a Mk1 recently had the two (how do you loose two of them...........) lead screw clamping nuts missing. To remake these 60(?) TPI nuts is a bit of a challenge and unless you have 20 made, it's not worth the bother. Worn out or missing multi-start lead screws that need remanufacturing are another problem. And don’t even mention those who have ‘lost’ the range and deflection shoe guide nut and spring tension screw. Minute threads externally and internally threaded too.

What I’m saying, and I’m sure I speak for others, is that if you’re missing bits or have butchered bits, then expect a hefty bill. Where was I now……….

[vintage hunter]

Peter, do you have or can you get hold of a set of 'prints for the lead screws and locking nuts? I described the lead screw to one of my machinist pals and he's reasonably sure he could make some. The only downside is there won't be a steady flow of them, sort of like on a made to order basis. Think it's worth a try?

[Peter Laidler]

Nope............, no drawings! He'll have to back engineer them individually to fit. And mention the words 'back or reverse-engineer' to any engineer and his day immediately goes into a steep dive. No known datum starting point and ........... Additionally, these things just ain't interchangeable either and have to be made to match. For example, I have had lead screws made as a threaded bar then match that section of thread to the lead screw nut. Then solder the outer end to make a fabricated piece as required. I've done the same with the Mk3/L1A1 lead screw locking nuts.

This'll be a lot easier for anyone contemplating making Mk2 telescopes afresh from, say, No53's because you just get 50 of each made identically to match 50 of something else made identically. The difficult bit is afterwards when you have to charge then explain to the customer the going rate

Another problem that is increasing is that the telescopes that seem to need repairs and overhauls now are those battered and broken old remnants that are not worth a light really and fit only for scrap.

Any other telescope repairers out there encountered non interchangeability