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The two convex surfaces face each other with the sprung spacer inbetween. I don't understand the meaning of the 'wide' and 'narrow'. The optical properties are the same. They are a matched set
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12-29-2015 12:10 PM
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Legacy Member
Thank you Peter
I think i understand.
There are two sets of lenses, both glued together.
if I look at them from the side they consist of a tich and a thin lens.
that was what I ment with vide and narow.
if I understand you correct the two thin ( most convex) shoud face each other.
it also look correct by markings from the retaning ring on the outher lens.
so once again, thank you
JSNE
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Legacy Member
Questions for Peter
HI Peter
I am almost done with convertion
Of my no.42 too a 32 mkIII
I foloved you advise
and it work out very well.
I bought you very good book : Telescope Sighting No. 32
On page 86 you whrite something about thread fore the leadscrews
you say 16 t.p.i ( multistart x2 = 32 t.p.i)
I am only able to make "normal thread"
so should i use 16 or 32 t.p.i?
Are ther always 84 click on the clikkerplade? Mk 1, mk 2 mk 3?
Best regard
Jsne
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32 TPI will give you the correct pitch to ensure that 1 click = 1 minute of angle. So cut 32tpi
84 teeth on the clicker plate is not the norm. The Mk1 is different but 84 clicks per revolution is correct for the Mk2 and 3.
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Legacy Member
Helo Peter
I am almost done with converting my scope no.42 too a
scope no. 32 mk III replica using your exelent instrucion.
all parts are produced and put together and working just fine.
the reticle was the hardest part. I am satisfied with my work (but it could bee better)
So now my quistion:
Is ther any place where I could buy a mk III reticle.
Best regard
Jsne
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It is simple to make one. The drawings are in the telescope book. That way, you make the graticle block to fit what you have made. If it is the actual post and crosswire, you are asking about you ought to PM me.
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Legacy Member
Helo again Peter
Thank you for the answer.
I mount my last atemp to make a disend reticle this evening.
And actually it looks verry well:-) I think at least!
The post is little to thick 0.007 and the only wire I could get was too thin 0.0005 on the label, but measured to 0,0007.
I think it will work for now. After all it is a homemade replica.
I dont know if other ever before have tried to convert a no.42 scope to a no.32 mk III replica after your instruction.
Here are some pictures
Best regard JSNE
Last edited by Jsne; 09-28-2016 at 01:06 PM.
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One for you Peter! I've managed to refurbish satisfactorily a few of these basket case No32's that came in from India, & up to now have been able to get away with the OG original lenses, or at least OG lenses from another No32. On this latest one though, I've used a complete set of lenses out of a No42. Everything seems to fit swimmingly, & the image is nice & crisp, but on test firing it it just wouldn't hold a decent group to save its life. I know the rifle is ok, & the bracket is properly collimated to it, so I can only think it must be my work on the scope. Could it be the lenses - even though everything seems ok when I look through it?
Cheers for any light you can throw on the problem.
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That's a good question DRP and set me thinking......... If it all seems tight then it can only be the graticle block that is moving erratically. But as it is spring loaded in a Mk3, it can't be and it would show in another way. Using No42 or 52 (53 threaded ocular cell only in a Mk3 don't forget.....) is a good idea because you're using a lens set that are already known to be compatible.
It is a little know fact that the OUTside diameter of the No42 and 53 OG lens cell is perfect for a No32 Mk1 and 2 telescope BUT........... But, the No42 and 53 OG o/d is approx .006"- 008" smaller than that of the Mk3 and this is where I think that you might have slipped up! If you do use a Mk1 or 2 or No42 or 53 objective lens in a Mk3 telescope it is not the nice tight fit that all men would like it to be...... Nope, it's slack and as such during each recoil the smaller diameter OG lens WILL move up, down or across the slightly larger diameter tube. Not a lot in physical terms of course but a LOT in accumulative and 3x magnified error terms. ON a target 100 metre target this will equate to a 15" or so group which is the very LAST thing that a sniper really wants.
This is because the OG lens is exactly what it says....... It is a lens and bends rays of light but in this case, bends the rays of light that put simply, projects the point of the graticle to your eye. What a bummer you're all saying. But there is an easy fix.
To make the old ex No42 OG lens fit properly into the No32 tube you will have to wrap 1x layer of .003 or .004" brass shim material around the outer diameter of the brass OG lens housing and slide it in. That's as tight as it needs to be. Close down and lock into place with the front shade.
While we're here, here's something else. In the outer diameter of the OG lens housing there SHOULD be a very small 10BA grub screw that sits very low, by about 3 threads or so, on the housing. This screw is a locator and slips into a narrow recess/slot in the tube. This prevents the OG lens housing and lens from rotating and holds it radially secure. If the OG lens does rotate it simply acts as a prism and does what all good prism's do, bend the rays of light making sure that you won't hit the target in the same place twice. Make sure that when you do anything that you don't tamper with this small screw
Last edited by Peter Laidler; 06-19-2017 at 01:52 PM.
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Thanks for that Peter. In fact it was a No53 that donated the lenses, not a No42 - my slip up. I can't see anything obviously wrong with the grat block or its fit into the tube, & it moves freely in both planes but is a snug fit front to back, with no obvious play. I hadn't realised about the few thou difference in the internal tube diameter, so that could explain it (I hope). I'll try some shim steel to fill the gap as it were, & then see what happens!
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