Re: [Leica] Disassemble a DR-Summicron

[John Collier <jbcollier@home.com>]

Please read all of the message before starting!
I have not done this work myself but the manual for the M2 has the
disassembly procedure for the DR. As you surmised, unscrew the retaining
ring, remove the pressure washers and then the optical component. Here is
where it gets interesting as there is a warning that states: "Optical
component is spun in lens mount. Removal may result in damage." Next Thomas
Tomosy (Leica Camera Repair Handbook) shares some ideas about how to get the
element out unscathed:

"Never pry at the lens! The easiest and the first thing to try is to invert
the assembly and let the element fall out into the palm of your hand or onto
a soft cloth. This can be dangerous if more than one element is mounted
together. If they were to fall on top of each other, damage would result. To
prevent this hold the assembly close to the surface so that only one element
can fall out at a time. Another way is to pull out the element with either a
strip of adhesive tape or a suction cup or suction bulb. Often the fit is so
good that as the element is pulled a vacuum is created inside the lens. In
this case you have to proceed slowly, letting the air seep in to relieve the
partial vacuum inside. If the element is really stuck, the only way to get
it out may be to push it out from the other side......"

Please be careful and reconsider whether or not you want someone who knows
what they are doing to clean it up.

Good luck

John Collier

> From: Min-yi Shen <smy@kff1.uchicago.edu>

> 
> I recently purchased a DR-Summicron from Ebay. After I got the item,
> I found that the rear element was severely scratched and the coating is
> nearly all gone. The worse thing is some of internal elements are fogged.
> Yeah, I can send it to Sherry and wish there will be some improvement --
> but I cannot wait for 4 weeks before it's back to my hand. Anybody here
> has some hand-on experience on disassembling a DR? I am a science grad
> student so the tools and chemicals are not a problem to me. I just took
> a look on the rear element in the optical part and found that it appears
> to be fixed by a black ring that has two notchs on each sides. Shall I
> rotate the ring or just pull it out?
>