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Xxx1
Tinkerer
Username: Xxx1
Post Number: 1
Registered: 04-2013
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, April 11, 2013 - 09:13 am: | 
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I got above lens cheaply as the lever pushing the aperture down was stuck. That was easy to repair (a drop of super lube oil and moving the lever few times did it, I think that this lens wasn't used at all or at least very little). It is Tokina made model.
Now the problem, I did lose clicks from aperture. I think that there should be a small bearing ball in a hole. I tried 1 mm bearing and it goes through it and 1.5 mm is too large. There seems to be no spring to push the ball outwards through the hole and I see no reason why it would get lost.
Micro-tools.de is out of 1.2 mm bearings so I am looking another source of them. Any other information welcome too, especially about Tokina&
their aperture clicking systems. |
Glenn
Tinkerer
Username: Glenn
Post Number: 1063
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, April 11, 2013 - 10:09 am: |
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Presumably the aperture ring covers up the hole where you think the spring and ball should be? If this is so there should be some grooves on the inner face of the ring that the detent ball locates in. The grooves may be directly under the aperture value engravings or may be located somewhere on the opposite side of the ring. I do not know this particular lens; however, if there are no detent grooves in the aperture ring that correspond to the hole when the ring is assembled in the correct position, then this hole is not for a detent ball. That does not mean that the hole did not originally contain a ball and spring - a number of good quality lenses (especially those with large diameter barrels ie large max apertures) have one or two extra balls that act purely as supports for the aperture ring. |
Xxx1
Tinkerer
Username: Xxx1
Post Number: 2
Registered: 04-2013
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, April 11, 2013 - 11:43 am: |
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Yes. There is a hole that corresponds to grooves in the aperture ring. Besides that hole there is another hole (maybe 15 degrees away) that I think had another ball for support. I have to check if there are more of these holes. There is very narrow countersunk in the hole. 1mm ball goes thru the hole and 1.5mm one makes the aperture ring too tough to rotate. So I think it has to be 1.2 (or 3/64") ball |
Xxx1
Tinkerer
Username: Xxx1
Post Number: 3
Registered: 04-2013
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, April 11, 2013 - 12:47 pm: |
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I got it working. The ball was 1.5mm but I managed to put two 1 mm balls inside the spring and the spring couldn't compress properly. Took them out and it works. I got that lens for 26.50 GBP and it is good enough for me. Weights 710 g and is about 1 kg with Sony Nex and about 1.5 kg with 24mm&55mm lenses.
Impatiently waiting for Sakar 135mm/2.5 with oily aperture blades. |
