Bodging a Jupiter

WARNING ---- Do not read if sensitive to bodging.

I have managed to acquire from SRS (lighting delivery) a Jupiter 85mm f2.

I've been hanging my nose over one of these for years, even bought the M42/PK adapter in readiness.

So, fitted it to my ist, and it jammed on! Not too bad, as I got it off without too much trouble, but a little leaf spring thingy broke off in the process. Bloody eBay tat!.

Anyhow, initial impressions are great, but here's the rub. I wan't to fix the adapter to the lens on a more or less permanent basis. To do this, it looks like I'll have to use some sort of adhesive, in minimal quantities to ensure that the adapter stays on the lens, and possibly drill a small recess into the rear of the lens body for the locking pin. I don't think that either operation will drastically affect the lens, at least if the adhesive is minimal, and the recess is neat.

That's how it looks to me, but I'd be grateful for opinions.

Don't know if my way will work but you can try to heat up the M42/PK adapter. The adapter will expand so you need to turn it so far as you can and when it cools down you might and shrink, you might end up with a good fixed adapter.

Or else a little bit of adhesive on the begining if the screw threat when you turn it on it will take it with it so that it covers most of the theat. if done right and if you haven't used to much adhesive then won't see a thing off it. I believe that only adhesive is good enough and that you don't need a screw to fix it in place.

We always used Loctite at KLM with the aircrafts so I think it will do good enough for your lens

Remind me not to fly with KLM, it seems their aircraft are held together with superglue

hehe you should know, and then to think that KLM has one of the beter serviceses. They're one of the few that do major overhauls for Japanese aircrafts.

Companies in Canada has one of the best maintenance in the world so if you're scared of flying, fly with one of them.

Having worked for over 30 years in aerospace, I would just like to put everyone's mind at ease on the use of 'Superglue' There are special aerospace grades, which are used by original equipment providers as well as maintenance centres.

As for Canadian maintenance companies, Standard Aero in Winnipeg are amongst the best, if not the best. They provide service the PW100 engine for KLM.

Steve

I did just that, a few weeks ago with a Pentacon 50mm f1.8. It is very easy.

The procedure:
Remove the spring clip from the adapter. Screw the adapter on the lens as tightly as you can by hand. Now you need to find exactly where to drill the hole for the locating pin. Coat the end of the pin with a blob of liquid Tip-Ex or other water based paint. Hold the pin in by keeping the button pressed and mount the lens. Release the button and the pin will make contact with the lens flange, leaving a circular paint mark. Remove the lens and the adapter from the lens. Now comes the scary bit!... With an automatic centre punch, make an indentation in the very centre of the paint circle. Use a 2.5mm HSS drill bit to drill a hole around 2mm deep.
Screw the adapter back on and mount the lens. If all is well, you should hear and feel the pin locate in the hole with a precise 'ping'.
now you can glue the adapter on the lens. I used Araldite rapid epoxy resin. Very little is needed. Apply it to the bottom of the screw thread of the lens and the face of the adapter. Screw it on and mount the lens. leave it on until dry.

If the thought of this makes you nervous, send me the lens and adapter and I will happily do it for you.

EDIT:
Very IMPORTANT...
Protect rear element of lens with masking tape while drilling, to avoid damage by swarf!

^^ I agree ^^

I've drilled a locking pin hole in the bottom of my Sonnar and it usually gets its own adapter. No need to glue the adapter, just ditch the metal clip and screw it on tight. If you ever need to remove it then do so with a rear cap from a K mount lens, under normal use it won't go anywhere...

Well, I've done the deed. No glue, just screwed it on tight. I've drilled the hole, slipping in the process, and quite frankly, it's a bit of a mess, but not too unsighly. It clicks into place quite nicely (living proof it's better to be lucky than clever!)

On a quick tryout, the image quality seems superb, even at f2. All I've got to do now is get used to the manual diaphragm stop down and then take some half decent images with it. Best £35 I've spent in a while.

I know it's too late but would Loctite have done this and also allowed it be removed with some effort at a later date? They have a large range of products and I'm sure one of them would have done the job.

Mike

The Jupiter-9 is a lovely lens so I'm sure you'll be glad you bought one. My main complaint with mine is that it's prone to glare (big exposed front element + lack of coatings = poor contrast) so I ended up buying it a rigid hood and that's made quite a difference, especially outdoors in the sun. Any hood with a 49mm thread would do but I like rigid ones as they offer a bit of protection against knocks.

Loctite - there are many types of Loctite. Most peopl eimmediately think of "Superglue" which would be wrong.

Find a local fastener supplier - bolts, screws, nuts &c and get one of the Screwlok or Threadlok products from them - 542 is one. It is used to hold nuts in place against gentle turning or vibration but can, with appropriate force be broken, cleaned off and the joint remade.

http://www.loctite.co.uk/uke/content_images/conv_pboxx-pixelboxx-95473_72dpi_605... shows how many types there are

Having screwed the thing on with some determination, I think that there is going to be no need for any form of adhesive. The forces applied in an unscrewing motion are very light. As a lens, it's uses are going to be limited to special occassions. Like most gadgets, the plain fact is, I just wanted it.

That's very honest of you, and there's nothing wrong in that. Most of us don't admit that to ourselves very readily!