[Leica] To the abyss and back with an Alpa Reflex Prisma, my story of repair, and sleep

[bruce at ralgo.nl (bruce)]

Fantastic account of your efforts, Vic. Hope the lens materialises!

B.

On 7-feb-2006, at 15:47, <vick.ko@sympatico.ca> wrote:

> To the abyss and  back with an Alpa Reflex Prisma, my story of  
> repair, and sleepliness
>
> A month ago, I bought a jammed Alpa Reflex Prisma off ebay.  It  
> arrived last week, looking in just fine cosmetic condition,  
> definitely far too nice to be relegated to the status of static  
> display or the horrors of the parts bin.  The glass was nice and  
> unmarked, the shutter curtain condition was intact and supple, but  
> the shutter and film wind was jammed.
>
> I searched the web for information on repair, and posted some  
> inquiries and got back some useful and encouraging information.
>
> Of course this story is all written after the fact.  The thoughts  
> and fears before the operation of opening up an unknown camera are  
> much different and intense than after the exercise, with questions  
> such as "what screws are there under the leatherette, how many  
> bizarre lockrings are there that need special tools, etc?
>
> Last Friday I took the basics off, like the lens mount and bottom  
> plate.    The bottom plate is a straight-forward removal, just  
> removal of all the externally exposed screws.  This exposes the  
> complete gear-train for the film advance and shutter mechanism.
>
> The top deck is harder.  I looked under the leatherette, but no  
> screws to be found.  Two cover plates are found with exposed scews  
> around the film chambers, so out they come  Some of their screws  
> are behind shafts, needing special contortions to loosen them off.   
> Now after the fact, I find that the film spool is removable, and  
> there was a srew behind it.  Had I known that the spool was  
> removable, a half hour could have been saved having to trick out a  
> screw with a slender screwdriver and toothpicks.
>
> Removing the top deck also means removng the prism, which isn't too  
> bad.  All the screws for the prism are accessible,and this is the  
> first place where I find a missing shaft.  This shaft would provide  
> a more secure attachment of the front of the prism to the body.  On  
> the positive side I find that the prism glass and focusing screen  
> are in really good shape although a bit dusty.  Now removed from  
> the body, the prism will bs really easy to clean.
>
> The top now appears to be loose, and can now be slowly removed.   
> But as I begin to separate the front and top from the body, parts  
> begin to fall out, namely then lens for the view finder and two  
> parts of its lensmount.  This is where the cold sweat breaks out,  
> not knowing where the parts come from, and what order they go back in.
>
> My strategy in these situations of parts dropping out is to  
> consider what the original assembly and design team were thinking.   
> Neither teams would have had magicians.   Parts have to go back in  
> by logical order, and must be able to be positioned without anti- 
> gravity tweezers or the like.
>
> The front faceplate and top deck ultimately come off as a single  
> entity.  The revolutionary aspect of the design is that the shutter  
> dial does not rotate when it fires, despite that the shutter dial  
> is on the wrong side of the camera.  Many cameras of that time did  
> not have a non-rotating shuter dial.  Removing the top deck also  
> exposes both the viewing finder and the rangefinder mechanism.   I  
> can now see what needs to bs done to realign the RF.  It is a  
> simple two-mirror rangefinder design, and the only lensed optical  
> assembly is the viewfinder, not the rangefinder.  And the optical  
> chambers for both the RF and VF are simply lined with black cloth  
> tape for light suppression.
>
> But still no clues as to why the jam exists.
>
> I pull on the curtains and deduce that the first curtain hs no  
> tension but the second one does.  This is sounding like a very  
> common Leica failure mode where a felt light baffle strip can get  
> lodged in the shutter curtain and tape.   But the chambers holding  
> the shutters rollers and spring rollers are still not accessible.
>
> So now Lius's email (from IDCC) on the camera holds the essential  
> clue, in that there is a seperate body housing that is sealed to  
> the main interior housing.  I go around looking for its seams and  
> find them.  I also go looking for where the attachment screws  
> are.   This is one major factor with classical cameras versus  
> modern ones.  With classical cameras, I can be fairly certain that  
> screws and fasterners are what holds the mechanisms and housings  
> together, and not glue or welding/soldering.  Sealng compound are  
> used for light sealing, not structural attachment.  Today, items  
> are sealed or glued together, and are incapble of offering viable  
> disassembly or reassembly.
>
> I find most of the attachment screws for the inner and outer body,  
> but also find that the entire RF mirror assembleis needs to be  
> removed.  This I one area where I will admit that the orignating  
> company had magicians.  I hate having to do optical alignments  
> without the necessary optical equipment.  But forging ahead, the  
> mirror mounts and pivots are removed.
>
> The outer shell is then slowly slid free of the body box, exposing  
> the shutter rollers and spring rollers.  Here, I find that the  
> shutter curtains are indeed intact, with only a minor tear on the  
> takeup side, and the tapes are fine.  I also find the errant spring  
> roller and have to remove it.  I slowly separate the shutter  
> curtain from the spring roller, but now find that I have to remove  
> one of the shutter timing gears.
>
> Gear removal is a another area of immense complexity; not so much  
> the removal but the need to properly retime things after.  I mark  
> all the gear locations and have to drive out a pin to remove the  
> relevant gear.  Having removed the gear, the spring roller is  
> extracted, and miracle of miracles, the spring is intact, and only  
> popped loose of its mount.  Reinserting the spring is trivially  
> easy, and the spring roller is cleaned up and reassembled, working  
> again.
>
> Now I merely need to reverse all the disassembly steps, and this is  
> the evil that many repair books end at, i.e. "reassembly is simply  
> the reverse of the disassembly steps.
>
> To move along faster with this story, I reassemble the shutter, and  
> the gear that I removed.  I can now fire the camera with some  
> semblance of proper shutter action, and discover that the gear  
> timing was the cause of the jam.  But this is what took the next 6  
> hours, discovering that the gear timing is completely off.  I put  
> it down to someone else had played with the gears, and didn't put  
> them back properly.  Hours are spent late at night to determine the  
> correct timing, but finally the correct alignment is found, using  
> the cocked state of the shutter as the reference.
>
> Ultimately, I get the shutter entirely reassembled, but find that  
> the fast speeds are adjusted properly but the slow speeds are  
> completely off.  If adjustments are made to the slow speeds to  
> bring them into specification, the fast speeds are entirely off.   
> this is a complete conundrum, as the two speeds are locked by the  
> single gear train.  After numerous hours of study and adjustment, I  
> final concede defeat and cheat.  I remove the bottom plate of a  
> second virgin Alpa Reflex and examine its gear train, and one  
> single gear is installed 90 degrees differently than what I have.   
> Moving the gear adjustment on the Prisma brings both speed ranges  
> into spec.  Relief and celebration, and short nap follow.
>
> The rest of the reassembly is pretty much a reverse of the  
> disassembly steps.  The rangefinder realign is another cycle of  
> trial and adjustment, including turning off the room lights and  
> shining a flashlight into the optical train to see where the  
> mirrors are actually pointing.
>
> The missing shaft for the prism mount is fashioned from a sewing  
> needle Holy cow is a sewing needle ever hard!   I'll never consider  
> buying drill rod for shafts any more; sewing needles are far easier  
> to find.
>
> Ultimately, the shutter is working well within spec.  My 4-1/2 year  
> old son can operate the shutter tester and has great fun cycling  
> through all the shutter speeds for me.  The rangefinder is working  
> "well enough".   The RF spot isn't quite centered, but to center it  
> would involve another full disassembly of the body plates,  
> something that can wait into the future.
>
> And the camera now looks beautiful and I have the inner peace  
> knowing that it works properly, is properly lubricated, and has now  
> become a "keeper".
>
> Now, if I can only find a lens for it ... anyone out there with  
> lenses from old Alpas that they don't want?
>
> regards
> ...Vick
>
>
>
>
>
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