[OK-944]

Scott - its been quite awhile since I’ve perused my engineering drawings…but a quick glance reminds me that, in general, we were working to +/- .005 for many parts, and down to either a +.001/-0.00, or a -.001/+0.00 (which for a different function might equal +/- .0005). There were a number of parts employing these “one-sided” tolerances.

This was a complex project…with many moving parts needing to interact with each other in different ways. There were interference fits, press fits, slide fits, and loose fits, depending on a required function. Tolerances for something like this are really tricky, and “ultra fine” can, in many cases, be counterproductive. Then again, to the extent that there are some interactive parts employing opposite one-sided tolerances…one might argue that the contact tolerance of those parts would be zero.

What complicated this further is an aspect of the hard-plate anodizing process (much more durable than just plain anodizing)…which is that while .001 inches of material is removed in the etching tank, .002 is added back during plating. This absolutely needs to be factored in during the design process. Also, depending on a given part and its desired function, one must be cognizant of the very slight degree of difference in actual plate thickness over the length of a given part, as electric currents can vary slightly from one electrode to the next, which is exacerbated further in the case of relatively long parts. I think of the long, metal on metal sliding/locking dovetail mechanism which allows my camera’s rear standard to move back and forth, which ended up operating with perfect, non-chattering (without play) smoothness and precision over wide temperature ranges…with virtually no lubrication needed saving for my occasionally rubbing the contact surfaces with my own nose-grease - how the entire process of creating this mechanism depended completely on working backwards to zero with full incorporation of all requirements going forward to make this part work. Kind of like how I make a photograph - able to see the final print and all it will take to achieve this at the point of my first viewing the subject on my camera’s ground glass. As an artist, I relate this ability to work with the totality in mind while also concentrating on each phase, to being “in the zone.”

Keep in mind here that machining is not my expertise, but as I was working closely with two senior engineers on this project, using a Solid Works program which allowed us to test all of the dynamic interactivity virtually (we could even dial in the sound that the rack and pinion would make during focussing!), also to test the effects of various types of stress (flexion, compression, temperature, chemical, etc.) - which, for example, allowed for the milling of weight-relief holes that made those panels stronger than if we’d just left them…it was my own expertise in the necessary workings of a camera which helped the three of us to become such an effective team on this project.

Rod - this camera measures a little smaller than seven by ten by three inches folded up, and weighs in at about 7.25lbs. Those huge, old, printing cameras you speak of...when that industry changed and those cameras were left to gather dust, some very enterprising photographers came out of the woodwork to salvage (free, or for a song) some of the truly amazing process optics employed by those cameras. (I was not one of those enterprising photographers).

Glen - Very significant, what you point out about the industry suddenly becoming flooded with used film cameras as folks migrated to digital, making it difficult even for folks like Linhof and Sinar to keep their own numbers healthy by selling new product. Things are a bit different these days, and there are a number of small-sized manufacturers becoming quite successful with the marketing of new large format cameras - although most of these are a bit more basic (and much less expensive to produce) than my camera.