[Leica] Re: M8 body shell

[grduprey at mchsi.com (grduprey@mchsi.com)]

Larry,

Don't know for sure how m bodies are made, but i seem to rmember brochures 
showing them being milled from a single block of metal.  maybe  one of our 
historians can clarify.  You are right though casting/extrusions do indeed 
get occasional flaws in manufacturing, and this is what i was trying to 
covey.

gene

-------------- Original message from Lawrence Zeitlin 
<lrzeitlin@optonline.net>: -------------- 


> 
> 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 
> 
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