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digital029art
Joined: 25 Apr 2008 Posts: 8 Location: Miami - FLL, Florida
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Posted: Thu Feb 11, 2010 8:04 pm Post subject: sourcing small springs for lens repair |
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digital029art wrote:
i have a sigma 400mm with weak aperture actuation. took it apart, blades are clean. i believe the culprit to be a small spring (possibly the pair of) just behind the mount. it uses the "clothes pin" style, maybe about 1cm on each side. anyone have ideas for a ready source??
(my other junk lenses don't use this type of spring~ and there are no small independent shops left in this area)
Thanks! |
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Spotmatic
Joined: 18 Aug 2008 Posts: 4045 Location: Netherlands
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Posted: Thu Feb 11, 2010 8:08 pm Post subject: |
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Spotmatic wrote:
I don't know what you mean with clothes-pin style, but many a lens have been repaired with springs from cheap plastic ballpoint pens. Just an idea! _________________ Peter - Moderator
Pentax K-5 + Pentax 645 + Canon 5D + Bessa RF 10,5cm Heliar, and a 'little' bag full of MF lenses. The lens list is * here *.
My fast 80s: Asahi-Kogaku Takumar 83mm f/1.9 - Super-Takumar 85mm f/1.9 - FA 77mm f/1.8 Limited - Cyclop 85/1.5 (Helios-40 innards) - Komura 80mm f/1.8 - Meyer Görlitz Primoplan 7,5cm 1:1.9 - Carl Zeiss Jena 80mm f/1.8 Pancolar - Canon 85mm f/1.8 S.S.C. - Canon 85mm f/1.2 S.S.C. Aspherical |
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digital029art
Joined: 25 Apr 2008 Posts: 8 Location: Miami - FLL, Florida
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Posted: Thu Feb 11, 2010 8:28 pm Post subject: |
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digital029art wrote:
sorry I don't have a pic handy, but it's not a compression spring (like from a pen), it has two legs pivoting in the center like this one on the right:
sorry for the size, only pic i could find
basically I need a stiffer spring to close the aperture reliably. _________________ Digital Serotonin Art of Flex Maslan
http://www.digital029art.com |
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indianadinos
Joined: 06 Jul 2008 Posts: 1310 Location: Toulouse, France
Expire: 2011-12-05
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Posted: Thu Feb 11, 2010 9:22 pm Post subject: |
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indianadinos wrote:
Hi,
I have sourced some of these springs from old junk bodies, notably the old Exakta cameras ... Usually you can get them for free from a repairman bin, or you could try to build one by yourself using a piano chord and a Dremel ... _________________ Please visit my blogs Shooting with a Pentax K10D / FF Visions
Takumar: 24/3.5, 28/3.5, 35/2, 35/3.5, 50/1.4, 55/1.8, 85/1.8, 105/2.8, 120/2.8, 135/3.5, 150/4, 200/4
Pentax-K: M28/2.8, K28/3.5, M50/1.4, A50/1.7, M50/4 Macro, K85/1.8, K105/2.8, K135/2.5, M200/4, M70-150/4
Zeiss: Flektogon 20/2.8, 20/4, 35/2.4, 35/2.8, Tessar 50/2.8, Pancolar 50/1.8, Biotar 58/2, Sonnar 135/3.5, Sonnar 180/2.8
Meyer: Primagon 35/4.5, Domiplan 50/2.8, Oreston 50/1.8, Primoplan 58/1.9, Trioplan 100/2.8, Orestor 100/2.8, Orestor 135/2.8
Schacht/Steinheil: Travenar 90/2.8, Travenon 135/4.5, Quinar 135/2.8, Quinar 135/3.5
Russian: MIR 37B, Industar 50/3.5, Helios 44M & 44M-2, Jupiter 37A
P6: Flektogon 50/4, Biometar 80/2.8, Orestor 300/4
Nikkor: Nikkor-O 35/2, Micro 55/3.5, Nikkor-S 50/1.4, Nikkor-Q 135/2.8
Fuji: EBC 28/3.5, EBC 55/3.5 Macro, EBC 135/2.5
Misc Lenses: Kiron 105/2.8 Macro, Tamron SP90/2.5
... and a few other Vivitar, Tamron, Sigma and Soligor lenses ...
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unclemack
Joined: 21 Jun 2009 Posts: 51 Location: UK frozen north
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Posted: Sat Feb 13, 2010 6:21 pm Post subject: |
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unclemack wrote:
Hi,
"took it apart, blades are clean."
I'm wondering whether you cleaned the blade carrier & ring right into the corners - everything that moves has to be scrupulously clean and free-running.
You can easily re-tension the spring if it really needs it, just bend it a little against its operating direction - the only kind of spring that can't effectively be re-tensioned that I can think of offhand is the mainspring on Compur, Copal etc. leaf shutters. These are extremely brittle. |
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unclemack
Joined: 21 Jun 2009 Posts: 51 Location: UK frozen north
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Posted: Sat Feb 13, 2010 7:01 pm Post subject: |
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unclemack wrote:
Oh yeah, forgot...
Check the mechanism between the mount & the diaphragm assembly for freedom of movement and alignment.
The length of the "prong" between the lens mount & the diaphragm on the 400 means that it has a lever effect on the ring at the mount end, trying to twist it.
Sometimes the ring will rotate freely until slight pressure is applied to the end of the prong, when it starts to drag. |
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wilson.c
Joined: 18 Jan 2010 Posts: 363 Location: Hong Kong
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Posted: Tue Feb 16, 2010 3:46 pm Post subject: |
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wilson.c wrote:
These guys have some parts for repairing manual cameras as well as cleaning digital ones. I've ordered a filter-ring undenter from them and it works great!
http://www.micro-tools.com/store/home.aspx _________________ Wilson
DSLR: Canon 5DMkII, 500D + Panasonic GF-1
SLR: Canon T90, Canon F1, Canon A1, Canon AE1 + Rolleiflex SL66 + Bronica ETRs
R'finder: Contax G1, G2 + Leica M6, M3 + Contax II
Lenses
M42: Angenieaux 90/1.8
Canon: FD 50/3.5 Macro, FD 80/1.8, FD 80-200L/4
Contax G: CZ Hologon 16/8, CZ Biogon 21/2.8, CZ Biogon 28/2.8, CZ Planar 45/2.0, CZ Sonnar 90/2.8
P-Six: CZJ Sonnar 180/2.8, CZJ Biometar 120/2.8
Contax: Distagon 28/2.8, Distagon 28/2, Planar 85/1.4, Makro-Planar 100/2.8
Others: CZ Sonnar 135/3.5 (Hasselblad V mount)
More little ones to be documented.
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