Repair a Seikosha (Mamiya C-series Chrome) shutter
Ok, I know, officially these are unrepairable as there are no parts. However, my 180 chrome went off last weekend. If you press the shutter release, the cocking lever comes back up half-way, then if you apply a gentle pressure to the lever from below, it finishes the travel, and the shutter fires. I'm also not entirely convinced that the sound made while firing is consistent.
So, does anybody have a recommended repair shop for one of these, or enough experience to say whether or not it's worth the cost of getting an estimate?
Bummer...a few weeks ago I unloaded a chrome 180mm on eBay that had bad glass, but the shutter was working perfectly. I only got $33 for it.
Originally Posted by fparnold
I'm no expert, but from what you describe it may just require a CLA (clean, lube, adjust), rather than a repair involving parts. I assume you've exercised the shutter a bit to make sure that that doesn't solve the problem (at least temporarily).
Two repair shops I've used and would recommend:
Paul Ebel in WI: 651-335-8759
Flutot's in CA: http://www.flutotscamerarepair.com
This is possibly due to dirty shutter, but also very likely that due to weakened main drive spring. This spring can last for many shutter cycles but it can get weak if you leave the shutter in charged position for a long time. (Store your shutter uncharged whenever it is unused for a long time.)
Originally Posted by fparnold
Mamiya OP in Tokyo used to be very reasonable in supplying parts, at least if I talk to the right person, but they no longer make cameras so the situation might have changed.
Incidentally, I have a Seikosha-S shutter in good condition, if you want to buy. I bought it with 180mm black lens from an unreasonable guy off ebay years ago. He must've mucked around this lens, since it has 180mm 4.5 black front groups, Seikosha-S shutter (which is typical of chrome lenses), and the rear groups from 250mm lens! The lens doesn't take sharp image at all, but it was advertised as "180mm black." The lenses have signs of amateurish repair but the shutter looks ok. The guy didn't want to take it back for refund. If anyone is interested in any of these parts, please email me directly.
That "half way release" is a dirty/gummed escapement. Springs don't tend to weaken unless severely corroded almost to the breaking point.
Try the Ronsonol trick, and/or send it to Carol Flutot.
-- Ole Tjugen, Luddite Elitist
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I've had the same happen with two of my lenses, and Paul Ebel restored perfect operation to both. Black or chrome,
Originally Posted by mgb74
these lenses seem to need service (CLA) from time to time. Paul right now has my 80mm lens that was
showing the early signs of stickiness. I'll bet he or Carol can have yours working
in no time.
"Good judgement comes from experience. Experience comes from bad judgement." - Jim Horning
The symptoms of weakened main drive spring and gummed timing assembly are very similar, and one very common way to discover the weakened spring is to clean everything and still see the sluggish shutter operation. I spoke to an experienced repairman at Mamiya in Tokyo some time ago, who told me a lot about Mamiya C and other cameras and lenses. He also mentioned that weak spring is common in Seikosha shutters for C lenses, especially in the older chrome ones (Seikosha-S).
Originally Posted by Ole
Apparently, weakened spring problem is more common in Seikosha mechanical shutters than in other lens shutters (although I've seen it in other shutters as well). The examples of weakened shutters I've seen were previously repaired by someone, and I saw graphite powder to reduce the friction in the driving and timing parts so that they could be driven by the weakened spring. That approach works only for some time. The real solution is to replace the spring.
PS. It seems that I initially misread the original post to have attempted a repair and still seeing shutter to fail, as it mentioned parts, etc. but I guess shutter wasn't cleaned yet. That would be the first thing to try, as others suggest.
Guys, thanks for the opinions and references. I actually had the shutter put through a CLA about two years ago, and it was flawless until it came out of the bag this trip. I'll call one of your recommendations, and get a quote. The camera and I are not fully comfortable with each other, but I've made some of my best pictures with it.
Finally, just in self defense, I don't store them cocked. I had a rather intense photo-mentor in college who was rather vehement on that point. (he was also vehement about "Dust is the Enemy!", as he waved his blower-brush around).