[Leica] Re: M8 body shell

[lrzeitlin at optonline.net (Lawrence Zeitlin)]

On May 25, 2007, at 6:14 AM, lug-request@leica-users.org wrote:

> grduprey@mchsi.com wrote:
>> Daniel,
>>
>> Overall i would agree, but the single piece body is much costlier  
>> to produce and probably repair.  Since everyone seems to beat on  
>> Leica about the cost of initial purchase and repair costs, and the  
>> need to reduce these in future products, this is probably why they  
>> went this route.  Then again just about every other camera company  
>> uses this method with little or no problem.  Another reason they  
>> probably did it this time.  I am leaning on waiting to see what  
>> the analysis of the failures shows at this time.  I am using mine  
>> on a hand grip mounted to the m8 so i can shoot one handed, and so  
>> far it has worked just fine with no indications of loose fit it  
>> stress.  I have another 7 weeks to go before i have use of both  
>> hands again.  The down side is it is very clumsy to work this way  
>> with the camera, and one handed is not good for shakeiness.  ;-)
>>
>> Gene


I may be mistaken but I thought that all RF Leica body shells from  
the urLeica through the M7 were extrusions rather than castings. The  
body chassis that holds the shutter, film transport, lens mount was  
either an assemblage of stampings (Leica 1 through IIIb) or a die  
casting (Leica IIIC through M7). I understand that Leica adopted the  
extruded body shell because it was cheaper to make. A side benefit is  
that extrusions are generally stronger and more ductile than equal  
wall thickness castings. All the rest of the marketing hype about  
rigidity, solidity etc. came as justification for the needle  
threading loading process. Leica found no need to use fixed backs on  
any of its other cameras.

If the M8 body and shell is a die casting, the base plate attachment  
failure may be due to an inclusion in the material or partial  
crystallization (or poor design). I'm no materials expert but I did  
serve as a consultant for a firm which made investment castings of  
aircraft engine turbine blades and complex castings of pistol and  
shotgun receivers. Flawed castings were not infrequent and parts used  
in critical applications went through elaborate testing procedures to  
identify minute cracks and flaws that could precipitate failure. It's  
not only the glass that needs careful inspection and a high level of  
quality control.

Larry Z