Mamiya C220F Focus Rack Backlash

Discussion in 'Medium Format' started by orsetto, Oct 18, 2019.

  1. This issue came up in a recent thread by stephen_poe (thanks, stephen!) with a more generic subject header (Couple of Mamiya C220f questions), but rather than tag onto that I thought starting a more specific thread topic thats more search-friendly might up the odds of assistance for stephen_poe, myself and any others affected.

    My recently acquired backup C220F has an issue with the focus rack/bellows retracting itself about 10-20% after extending it out to maximum (minimum?) near-macro focus. Its difficult to figure out what might be causing it, as it seems to vary somewhat depending on the lens attached. The "backlash" effect is more pronounced with the shorter lenses 55mm-65mm-80mm-105mm, with the 135mm its less severe and the problem goes away entirely with the 180mm Super mounted. Nothing like this has occurred with any other Mamiya TLR I've used (various older C220, my other C220F, my C330S, or older C330f). Note this is the final all-black C220F variant with one-touch automatic WLF, not the far more common silver-trim C220.

    See below for pics of the focus scale, showing maximum extension on top, then the backlash position it retracts to if you let go of the focus knob. In day to day use it isn't a huge problem because it only affects very close settings (with the 80mm, maximum extension roughly frames a face from forehead to lower lip, the backlash pulls it back to a tight head and shoulders). But it annoys me that its there, and I'm afraid it may worsen. Anyone have any idea how to fix this? Removing the bottom cover doesn't reveal anything obvious. Thanks!

    Mamiya C220f Backlash.jpg
     
    Last edited: Oct 18, 2019
  2. Just thinking out loud, could a tight bellows cause this? What does it do with no lens on it?
     
  3. I'd thought the bellows might be a contributing factor, but it doesn't really seem any different than my other C220F: focus feel and smoothness is identical, with no stiction or stiffness in the bellows material. My gut instinct is that there's some sort of counterbalance/tensioning mechanism operating on the rack thats a hair out of neutral adjustment, but I could be totally wrong. When I take off the bottom cover it appears to be a simple rack and pinion inside, but there could be a spring clutch concealed somewhere in the axle or one of the two focus knobs.

    The backlash / unwanted retraction is worst with no lens mounted: even more than the pics above (the rack withdraws nearly a third of its length). If the 220 had the focus lock feature of the 330, it would be a moot point, but the 220 relies solely on inertia to retain focus setting. Something in there is artificially pulling it backwards.

    Realistically I could probably learn to live with it as long as it remains in the below-meter closeup range. The 220F is the rarest Mamiya TLR body, usually fetcheing double or more than what I paid for it ($200). The fully enclosed one-touch WLF, enlarged winding and focus knobs, and ultra-bright screen make it much more pleasant than the standard C220 with its dim screen and horrible WLF. Too bad its ugly as sin: a black plastic clad lump, the Pontiac Aztek of TLRs (stealing the crown of "least distinctive looking TLR" from the equally blah-black-lump Yashicamat 124G, which has chrome-faced filter bayonets to break up its monotony). Functionally, the C220F is a joy to use: I'd really like to solve this one's focus backlash issue.
     
    Last edited: Oct 18, 2019
  4. This isn't backlash, per se, which applies to looseness between the rack and pinion. "Spring-back" might be more accurate. It occurs with any bellows mechanism, and is usually countered by locking the setting (e.g., view cameras and enlargers).

    Bellows get stiffer with age, which is probably the root cause of the problem. Wear in the rails would be another factor. A thorough CLA would be appropriate, possibly replacing the bellows too.

    There is probably an adjustment between the camera body and rails of the rack which would increase the friction and hold the setting. Silicone grease, of the sort used for focusing helices in lenses, on the rails, could help too. Great care must be taken to avoid contamination of the optics. Silicone adversely affects the efficiency of coatings, and is nearly impossible to remove. The camera probably has brass bearings for the rails, which need little or no lubrication.
     
    orsetto likes this.
  5. Thanks for your input, Ed_Ingold: much appreciate your taking the time.

    Yes, logically it would seem the bellows itself is retracting, but you'd need to handle the camera to understand why it appears something else or additional is involved. Its hard to describe, but it retracts with exactly repeatable, significant force (maintaining a light touch on the focus knob, you can really feel the spin friction as it pulls back, like your fingers are fighting against heavy spring tension pulling on the rack). If it were the bellows alone, I would expect the retraction to vary more, and not rub so hard against the fingers (a light touch should stop it entirely, at least for a couple seconds).

    Like stephen_poe, I have tried extending the bellows to maximum and leaving it locked in place with a wood block for several weeks, to no avail: remove the block, and the damned thing retracts with as much force as it did before. If it were the bellows alone, one might expect the weeks-long stretching to have some effect, but no dice. Given the very reasonable price I paid, I'm not averse to having a tech look it over, but even here in NYC most techs are younguns specializing in DSLRs: their eyes glaze over when I bring in archaic old film gear. Rather than subject it to exploratory surgery, I'd like to attempt DIY if at all possible. Since I managed to remove/reinstall the lens mount drive gear to unjam a hopelessly seized Hasselblad, this Mamiya should be manageable if I can get a clue where to target my efforts.

    While I would not be surprised to discover it is in fact an anomaly with the bellows itself, prior experience leads me feel the bellows isn't strong enough to snap the rack back with such force by itself. Before deciding I prefer the simpler 220F design, I owned two of its sibling C330S bodies. Each had sat unused for so long before I got them their bellows had hardly ever been extended, which led to a crackling sound of resistance every time they were focused. Despite this, even with the adjustable C330S focus drag set to "loose", even if the camera was pointed at the sky, there was no retraction issue whatsoever.

    Puzzling.
     
  6. Hearing that you extended the bellows for a period of time only to see no improvement DOES point toward something else as the cause. I agree you got a great deal on it and a good DIY repair is the best way to go. If I come across anything that can help I will pass it along.
     
  7. orsetto likes this.
  8. Thanks for the repair manual link, andyfalsetta. Yes, I had seen this first-version C220 manual some time ago, but had not thought to check it for this problem due to some significant construction differences between the original C220 and my late C220F that has the retraction issue.

    Appreciate your pointing out the specific schematic relating to some complexities in the focus pinion assembly: that might lead me somewhere, if I can figure out how it applies to this newer C220F. Unlike the earlier model, the F update has no peel-off leatherette on the body or knobs: the "leatherette" pebble grain pattern is molded directly into the plastic surface panels and knobs themselves (which cover the steel skeleton underneath). So it is unclear how one would go about removing the focus knobs to access the focus tension springs. This repair manual for the original C220 suggests peeling the leatherette off the knob to access a hidden set screw to remove the knob, en route to the spring, but since the C220F does not have peel-able leatherette it must have some other method for removing the knobs.

    I'll look into that more closely, thanks again for giving me a lead!
     
  9. C220 - C220F... how much difference could the letter "F" make? Seriously, good to know; there is a lot to learn with the Mamiya TLRs. I guess the biggest take away from the C220f manual is the clue that the focus rack slippage was "engineered in" at the time of manufacture and that the fix was to add a controlled bind to the mechanism. If one didn't know better it would appear they were fixing the symptom, not the cause. But Demming would never have let that happen... :) Maybe they accomplished the bind with a simple spring washer that some bonehead tech left on his bench at one time. You'll figure it out.

    As an aside, I have taken to using automotive leather cleaner and conditioner on my bellows-equipped cameras. The two Lexol products are applied with a Q-tip and it seems to help restore resiliency to the leather.
     
    orsetto likes this.
  10. The first thing that came to mind was something inside the body that's catching the traveling chassis in such a way that it still allows movement of the chassis but wants to spring back into place. But then you said ... "and the problem goes away entirely with the 180mm Super mounted" ... could it be that the extra weight of that lens is somehow affecting operation of the traveling chassis ?

    Just for the time being though, does your frame counter work normally ? There's a flat horizontal rod adjoining the shutter release that moves the counter to the next frame number when the shutter release is pressed. Firstly check if everything is normal with that
     
    orsetto likes this.
  11. I just posted and it mysteriously disappeared into the ether

    It was about your frame counter, is it working normally ? the flat horizontal rod from the shutter release might be jamming
     
  12. Thanks for the suggestion, kmac: yes, all is well with the frame counter coupling.
     
  13. Just for reference, here are some pics to show the external differences between the original Mamiya C220 (left, 1968 thru 1982) and revised final Mamiya C220F (right, 1982 thru 1992). Upon examining my 220F with a magnifying glass after re-reading the C220 repair schematic provided by andyflasetta, I noticed I was wrong: the later 220F does in fact have peel-off leatherette coverings. They are applied with such precision that they seem molded into the plates and knobs, but actually should be removable. The 220F leatherette material does seem like it would be stiffer and much harder to remove/replace intact than on on the C220, OTOH the pebble grain is much easier to match with generic leatherette replacements than the proprietary "Embossed M" leatherette of the C220.

    Mamiya C220 vs C220F 01.jpg
     
  14. SOLVED! :)

    Figured it out, friends. While taking the above pics showing the differences between the early and late C220 models, I noticed a very distinctive change in the focus knob mounting mechanism. The older C220 does not have any obvious way of altering the focus rack kickback tension without peeling the leatherette off the knob, and disassembling it to access the springs. My late C220F, the subject of this thread, has a wider gap between the body and focus knobs, and the axel/bushing of each knob has three tiny set screws poking out around the circumference. On a hunch, I used a small jewelers screwdriver to try tightening the most accessible front-facing set screw on each focus knob.

    To my shock, this simple adjustment actually did the trick: it increased the drag on the rack/pinion a tiny amount, just enough so the focus position remains fixed at any position (even maximum extension) with any lens. Compared to my older C220, my other C220F, and a C330S, this "problem" C220F now has the exact same focus feel (a trifle firmer than it was before), and the focus rack no longer retracts on its own (no kickback).

    HOWEVER: caution is advised in making this adjustment. Based on my prior experience with this kind of set screw in other Mamiya and Nikon gear, I knew to make sure I tried several similar but not identical screwdrivers. You need the tip to EXACTLY fit the slot of the set screw: if its too thick or too thin, it will shear the slot right off the set screw (try different brands of the same screwdriver size: each brand will vary in blade thickness at the same blade width).

    Also, the screws are held in place with a drop of clear epoxy which you may or may not have to fight against: I'd suggest dissolving it first with a drop of alcohol. In my case. it seems the prior owner had loosened the screws to obtain a lighter, silkier operating feel, so the epoxy had already loosened its grip. Because I wasn't sure what I was doing or if it would even work, I only attempted to tighten the screws by about a half turn to the right: this turned out to be perfect, so don't overdo it.

    MANY THANKS to all who posted here with suggestions: they helped lead to the correct answer. You saved me a great deal of trial and error, and perhaps subjecting this poor camera to unnecessary disassembly. Since there are virtually no updated repair manuals available for the scarce 1982-1992 C220F and C330S, handing them off to random repair techs who may not know their differences from the much more common older versions is something to avoid if possible.

    Mamiya C220F Focus Tension Screws.jpg
     
    steve_gallimore|1 likes this.
  15. The design is similar, the execution differs in some significant respects.

    "Just for reference" (like the pics above), since the C220F and C330S updates rarely come up in forum discussions this seems as good a place as any to note the changes that were made:

    1. Most significant from a usability standpoint, the focus screens on the 220F and 330S are vastly better than the screens on the older 220, 330, and 33 variants. Much brighter and contrastier, with more obvious "snap": there is no necessity whatsoever to look for a third party, expensive screen update as one often does with Rolleiflex, older Mamiyas, Hasselblad, etc. The design of the 220F/330S screen itself and the mounting mechanism is completely different and utterly incompatible with the previous Mamiya TLRs.

    The original C220 has a fixed, non-user-changeable screen with two-piece groundglass + fresnel and complicated mounting (like the original Hasselblad 500c). The screen can be changed for a modern one, but the procedure is not for the faint of heart. The later C220F also (technically) has a fixed non-user-changeable screen, but it doesn't matter because its already a fantastic screen. Since it uses the exact same new-design screen as the C330S, it has an undocumented ability to swap out the standard screen for any of the interchangeable C330S screens (split image, grid, microprism). The 330S features an easy, pushbutton screen release (the frame pops up, and you slide the screen in/out ala Olympus OM or Nikon FE): to change the screen in the 220F you simply remove a screw (located where the 330S screen release button is located) and the frame pops up. The older incompatible C330 screens are clumsy, unreliable contraptions involving foams (basically the entire top of the camera including the screen gets interchanged).

    2. The 220F and 330S both come with the latest, fully enclosed, one-touch waist level finders. These are, like the new screens, vastly better than the awful WLFs on the older C220, C33, C330, and many C330F bodies. The older WLF has three short folding panels and a magnifier on a flap that floats above, allowing loads of ambient light and reflections to obscure what is already a flat, dim screen. The 220F/330S WLFs have taller side panels that seal against the magnifier flap like a solid magnifying hood: no ambient light or reflection interference.

    3. The 220F has very different location for the lens release and single/multi exposure knobs than any any other Mamiya TLR.

    4. The 220F does not have a folding crank near the top deck like the older C220: it has a larger, crank-less knob relocated to the center of the camera body. It winds as quick and smooth as a crank, but some people really miss having a crank option. Because the knob was relocated, the entire film advance mechanism was redesigned. Some feel this new design is more fragile, but I've yet to hear of a C220F with advance problems.

    5. C220F/C330S both have larger focusing knobs, eliminating the need for the clumsy add-on "big knob" Mamiya offered for years as an accessory.

    6. 5. C220F/C330S both switched to the new-style Mamiya RZ67 strap attachment lugs, as opposed to the simple strap slots in the older C220 etc.

    7. C220F/C330S both have a new, hidden two-step film door release which is easier on the fingers than the old door-mounted silver dial. Instead, you press down on a tab while pushing in the upper film spool knob to pop open the back (which now also has a film box end flap holder).

    8. As I discovered in the course of this discussion, the 220F focusing mechanism differs in some particulars: it has some external adjustment points that don't require as much (or any) disassembly.

    9. The C220F was only available in all-black trim, as opposed to the original C220 which was chrome trim only. Many of the 220F external body panels are high-impact plastic vs the steel of the older C220. Despite this, the C220F isn't any lighter weight and seems equally sturdy (drop either onto a sidewalk, and it will dent the sidewalk as well as itself).

    I've used all the Mamiya TLRs, but eventually decided to standardize on the C220F. It is the lightest, quickest operating, ruggedest, easiest to handle Mamiya TLR that still has the great new focus screen. Nowhere near as pretty or svelte as a Rolleflex or Minolta Autocord, but not unbearably heavy like the 330 models. The bright screen, built-in macro bellows, ambidextrous focusing knobs, and interchangeable lenses make the C220F a unique proposition among TLRs. Not an easy camera to find, and not the bargain it used to be, but well worth an audition if you like TLRs.
     
    Last edited: Oct 21, 2019
  16. Glad you found the problem orsetto, it's always satisfying hitting on the fix without having to send to a repairer. A blog I was reading had a poster who said KEH does that adjustment/repair

    I was checking out my C3 and there's no set screws so it could have the same tension arrangement as the C220, where ever it is and however it's executed. Hopefully I'll never need to find out. The focus is quite firm on the C3 and I think that's how these Mamiyas TLRs' are meant to be
     
  17. Glad you were able to solve the problem without having to hand it over to a repair person! Good job!
     
  18. "Just for reference" (like the pics above), since the C220F and C330S updates rarely come up in forum discussions this seems as good a place as any to note the changes that were made:




    4. The 220F does not have a folding crank near the top deck like the older C220: it has a larger, crank-less knob relocated to the center of the camera body. It winds as quick and smooth as a crank, but some people really miss having a crank option. Because the knob was relocated, the entire film advance mechanism was redesigned. Some feel this new design is more fragile, but I've yet to hear of a C220F with advance problems.

    5. C220F/C330S both have larger focusing knobs, eliminating the need for the clumsy add-on "big knob" Mamiya offered for years as an accessory.

    6. 5. C220F/C330S both switched to the new-style Mamiya RZ67 strap attachment lugs, as opposed to the simple strap slots in the older C220 etc.

    7. C220F/C330S both have a new, hidden two-step film door release which is easier on the fingers than the old door-mounted silver dial. Instead, you press down on a tab while pushing in the upper film spool knob to pop open the back (which now also has a film box end flap holder).

    8. As I discovered in the course of this discussion, the 220F focusing mechanism differs in some particulars: it has some external adjustment points that don't require as much (or any) disassembly.

    9. The C220F was only available in all-black trim, as opposed to the original C220 which was chrome trim only. Many of the 220F external body panels are high-impact plastic vs the steel of the older C220. Despite this, the C220F isn't any lighter weight and seems equally sturdy (drop either onto a sidewalk, and it will dent the sidewalk as well as itself). (Partial quote)

    ...when Mamiya updated the c220 to the 'F' model they created a camera that shared more parts with the c330 'S' (which you listed). Perhaps most conspicuous was the wind knob - now located in the same position as the wind crank on the c330. Presumably the gearing inside the two cameras is now the same. The side panels on both cameras seems very similar too - but I think they are metal on the c330. Are you sure the c220 F is plastic in this area? If so perhaps it could be referred to as the c 220F dash 166.
     
  19. Good questions: prompted me to closely examine my latest C220F today, the one under discussion here that had the focus rack issue. For the past several years that I've owned the final Mamiya TLRs, I assumed the conventional "web wisdom" about plastic side panels cladding the 220F to be 100% true, but now that I really look closely I see this isn't quite correct.

    Perception is reality, as the saying goes: if you previously owned the more "battleship build" C330F and/or original C220, or the insanely sturdy C33, the final models do give an immediate impression of cheaper build which fits in with the web reputation. The fit and finish of the 330S doesn't seem as good as the earlier 330F, and the 220F goes way overboard on the plastic: if you've handled both, they can blur together and seem more similar than they really are.

    The 220F has so much plastic on it that is easy to assume the side panels are as well, with the odd bespoke leatherette giving the distinct impression it is surface molded in the plastic-appearing side panels. As noted in an earlier post above, it wasn't until I pored over the camera with a magnifying glass to repair the focus tension that I finally saw the leatherette is not actually molded into the sides: for some strange reason, Mamiya simply devoted inordinate care to make it look like its molded. Its almost impossible to see the edges of the leatherette, so finely is it inlaid (far better than on any other camera in Mamiya's or most other mfrs history).

    Both the 330S and 220F have plastic base covers and plastic knobs, dials, index plates vs the older models metal. The 220F goes further with its unique WLF also being entirely plastic, and various plastic portions of the side panels like the distance scale index again being so seamlessly attached they appear to be part of one intact plastic shell. As with the leatherette, this is impressive but deceptive: the side panels proved to be metal after all, with smaller plastic elements meticulously welded into them. The plastic parts are so flawlessly integrated with the metal you'd almost need to disassemble the body to verify the side panel materials. Or, do what I just did: scrape the edges in an inconspicuous corner to see if paint chips off (yes:eek:) or a plastic gouge results (noo_O).

    Re the 220F film advance: it does seem Mamiya relocated the wind knob to the same position as the 330 crank, presumably to consolidate parts across both models. This bothered some long-term enthusiasts, who felt the simplified 220-specific film advance was much more reliable than the fussy 330 crank assembly with its additional external shutter cocking duties. And indeed, if you audition both final models, the C330S crank wind feels like a hollow unpleasant rattletrap compared to the old C220 crank, which easily gives the impression the C220F/C330S were both cheapened by the parts share. But after using both with film, one instantly feels the big crankless knob of the 220F operates way smoother than the crank of its sister 330S: they may share the location and some parts of a common film advance, but on feel alone the 220F should be nearly as trouble-free as the older 220.

    Thanks for prompting me to really dig in to my 220Fs, neil_grant: more than ever, it confirmed my gut instinct the C220F is the most well-thought-out TLR Mamiya ever offered! :) Got rid of my 330F and 330S awhile back, to standardize on a 220F and an older 220. Now that I've found and repaired a backup 220F, my TLR system is perfect for me.
     
    Last edited: Oct 31, 2019
    rudolph_alvarado likes this.
  20. ...I recently got a C 330 S (wanting a simple, reliable, square format camera) - and thinking this was the best of the line. No sooner had I done so I came across reports of plastic in the construction (including the side panels) and I was rather disappointed in this. I examined the camera carefully and it seemed to pretty much like the C 330 i remembered from thirty years before. I began to doubt the plastic side panel description as they seemed cold to the touch and fine scratches in the paint revealed 'brightness'. As you note, the focusing screen is especially clear and easy to use. I use mine with the prism and a left hand grip - and of course it is quite bulky.
    Cheers!
     
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