| Author |
Message |
    
Westcoastpete
Tinkerer
Username: Westcoastpete
Post Number: 1
Registered: 06-2013
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, June 28, 2013 - 06:43 am: | 
|
Hi All
After much time spent building and fixing bicycles, I've found a renewed interest in film photography, and along with it, film cameras. As I'm sure many of you know, there are many good cameras around that just require a little bit of TLC, and I'd like to attempt giving them that TLC when possible.
So this is my first bit of camera repair! The shutter from this Mamiya 6 folder sticks at speeds of 1/10th or below. I believe that the problem relates to friction between the speed selector ring or the arm on that ring and the paddle on the small speed aperatus.
I'll post a link to a video I made in the next post (just in case youtube links are unwelcome; this is my first ever post on this forum that is new to me).
Thanks |
Westcoastpete
Tinkerer
Username: Westcoastpete
Post Number: 2
Registered: 06-2013
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, June 28, 2013 - 06:47 am: |
|
http://www.youtube.com/watch?v=YK6P1hvuqDs&feature=youtu.be |
Fidji
Tinkerer
Username: Fidji
Post Number: 49
Registered: 12-2011
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, June 28, 2013 - 08:18 am: |
|
Not had any experience with Seikosha shutters, but the problem is most likely to be dirty gears in the slow speed escapement. Try flooding the escapement unit with a lighter fuel. If the slow speeds don't speed up after cocking and releasing the shutter several times, try more fuel, and try some on the shutter blades. |
Br1078lum
Tinkerer
Username: Br1078lum
Post Number: 581
Registered: 11-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, June 28, 2013 - 08:25 pm: |
|
It's best to take the speed escapement out for the cleaning. Usually two screws, one at the top (that is also an adjustment point for the speeds), and another at the bottom. The one at the top needs to be exposed by cocking the shutter, so the catch levers get out of the way. Use some high quality screwdrivers, and you may also have to modify the tips to fit properly in the screw slots. Or buy a set of JIS drivers.
I put my escapements in a plastic cap from a peanut butter jar, give them a good dousing of lighter fluid, then work the gearing back and forth before blow drying it. Looks very similar to a Compur-Rapid, so shouldn't be hard to do. Just be aware of flying springs! You can also remove the Self Timer mechanism for a good cleaning too.
Still, a Compur-Rapid, or Seikosha Rapid shutter are not my idea of a first-timer sort of repair. Read up on posts in the Archive here.
PF |
Br1078lum
Tinkerer
Username: Br1078lum
Post Number: 582
Registered: 11-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, June 28, 2013 - 08:31 pm: |
|
This set shows a Compur-Rapid I cleaned, if you want an idea as to what needs to be done.
http://flic.kr/s/aHsjCbMYma
PF |
Westcoastpete
Tinkerer
Username: Westcoastpete
Post Number: 3
Registered: 06-2013
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, June 29, 2013 - 08:04 am: |
|
Thanks for the replies and tips.
I feel that the slow speed escapement is not the problem. Perhaps it is, but I when I manipulate it manually it appears to work perfectly. I am hesitant to take it out because apparently the shutter speeds are calibrated by the position of the escapement. I could carefully mark where it is, remove it and clean it and hope that I get it back in the same position, but I haven't got any device to test the speeds so am reluctant to move it.
I haven't had a chance to return to this project for a few days. I'll have another look in the next few days.
Thanks again! |
Rick_oleson
Tinkerer
Username: Rick_oleson
Post Number: 1321
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, June 29, 2013 - 10:37 am: |
|
You can clean the escapement pretty well in place, with a few drops of lighter fluid applied to the pallet and star wheel of the escapement. Gears further downstream aren't as sensitive to dirt because of the greater power that's applied to them through the gear reduction.
You may also find that the blades and their actuating linkage are dirty and sticky. To clean these in place, I would use CRC "QD" Electronic Cleaner instead of lighter fluid, because it dries faster out of the tight spaces in the blade mechanism. Remove the front and rear lens cells, spray the blades and immediate surrounding area and operate the shutter several dozen times to work the solvent through the system while it's still wet. It may require a few repetitions to flush the dirt out (hold the shutter in a paper towel so that it will trap the dirt coming out of the shutter).
If the escapement is still in place during this operation, this will probably take care of cleaning it at the same time, so you may be able to skip the lighter fluid treatment on the gears.
Make sure to recheck all speeds after it's completely dry before reassembling. |
Br1078lum
Tinkerer
Username: Br1078lum
Post Number: 583
Registered: 11-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, June 29, 2013 - 11:34 am: |
|
Adjusting the speed on the escapement usually just involves timing the 1 second setting. Everything else is correct then.
You loosen the top screw, and swing the escapement either towards the lens barrel, or away from it, depending on how fast or slow the 1 second setting is. I don't remember which direction is faster, but it doesn't take long to reset it.
Some shutters instead have a small gap slot just above the pallet that has to be adjusted by bending it. Probably why older shutters had to have their escapements replaced so often, as one could break it while doing the adjustment.
PF |
