PPco Occular Housing thread

Hi Guys

Recently been given the opportunity to buy a couple of PPco scope parts. Its something I don't really want to pass ip on as spares are hard to come by. One of the scopes the long cone version has a crushed ocular housing but the tube and internals are in very good condition. The other scope is a earlier stepped cone but the tube is rotten and some internal parts are missing but the ocular housing is in great condition. Between the two you could make one good scope so my question is are the two ocular housings interchangeable? Will the stepped cone housing fit on a long cone tube and would it be functional optically.

would be interesting to know before I cross anyone's palm with silver.

Regards

MAC

If I was you I'd try them - or ask him to try it before you buy. I would imagine that they're interchangeable - theoretically! But whether they will be in practice is quite another matter, as we quickly learn with the No32 telescopes. Same drawing, different rulers as we used to say!

Quote:

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Originally Posted by Peter Laidler

If I was you I'd try them - or ask him to try it before you buy. I would imagine that they're interchangeable - theoretically! But whether they will be in practice is quite another matter, as we quickly learn with the No32 telescopes. Same drawing, different rulers as we used to say!

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Hi Peter

thanks for reply.. I did ask that but the guy stated that the ocular housing was stuck and essentially its sold as is.. I get the impression he isnt willing to mess around with it. I do have another long cone version but i can't undo the ocular housing on that either and id rather not mess with it as its optically excellent..for a 100 yr old scope that is and id rather just leave as is.

So id be happy to hear from anyone who has both and is willing to see if both housings are interchangeable.

Regards

Mac

Like I said........... Even if the 'anyone else' has a pair that fits/matches, the same No32 rules apply. HIS might, but your's might not. Same drawing, different rulers! Have you ever tried to fit different manufacturers ocular lens counter cells? Or what about cursor slides?....... Sorry, just the pessimist but REALISTIC pessimist in me!

Thanks for reply Peter

Re counter cells, cursor slides and ocular housings.. quick answer no.

Not really an option with a S&B. If we did have issues which was rare we used to send them back with the long to Guys like you to deal with.

Though we are talking much more modern optics in that scenario.:)

I agree regarding your No32 rules.. perhaps I should have re worded it and asked if anyone has had any success interchanging them rather than if they are interchangeable I guess I will have to buy blind and take my chances.

Thanks for heads up, at least I know there is a possibility either side.

Regards

MAC

The best - or worst, depending on your point of view - was the OG ray shade at the end of the No32/42/53/71tube. You have a job getting any of them to fit another scope.

Oh yes... I have had various different spares including objective ray sheilds and ocular lens rings to name but a few for the 32scope in the parts bin of my fathers place, Many different makes too and I know first hand that a lot of the visually identical parts annoyingly don't fit other No32 scopes. Too be honest I didn't realise that this would be a potential issue with the PPco ocular housings as it was only made by PPco and no other contractor and seemingly used a standard thread but as you say you can never tell.

regards

mac

I'll check a few of mine out for you when I get home later but if memory serves they are actually interchangeable.

Cheers,

Simon.

The trouble comes not when they actually screw in, but when they screw in LOOSE. That way you effectively have a prismatic lens and if you have a prismatic lens or in our scenario, a lens that moves, albeit very slightly, then all is lost

Guys thanks for all your replies I do appreciate it. With peters advice at least we know what to potentially expect and with this in mind Simon I'm sure you will be ultra careful when attempting to trial it after all these things aren't exactly growing on trees.

Many thanks

Mac

Mac,

I've done a bit of swapping and changing around have found that the Ocular housings will indeed interchange, the threads picked up no problem and when screwed fully home the focus only required slight adjustment which I guess is only to be expected.

One thing I did notice which I never have before is that the ocular housing on the later tapered cone bottoms out against the recoil ring. Obviously the later cone was produced to simplify manufacture but it got me thinking how the earlier stepped cone was manufactured and I can only assume it was by metal spinning? A somewhat diminishing skill in modern times although oddly enough a Company less than a mile away perform that very same function.

Cheers,

Simon.

I think metal spinning died out with the old trade of coppersmiths

Unfortunately like the majority of the old Engineering skills and trades this country was built on.

Simon, thats great news thanks for trying that. At least I know now its possible to interchange the housings. In regards to the long cone.. yes I've studied mine and although I cant unscrew it yet it appears to be made from a sheet of brass which has been formed or pressed into a cone then the the closing edge soldered. There is a clear straight solder line where the two halves meet. You mention the long cone being later.. I guessed this was a 1916 onwards version as don't think ive seen any photographic evidence on that version prior to that date but have on the stepped pre issue version which unknown to me has a collar that can unscrew as well. Im sure this version has the join line too. Re spinning..

I currently use two companies and they are both very good. Both are in london and are happy to negotiate prices or do the odd cash in hand option which is cheaper for me. Pm me if you want details.

Regards

Mac