My "brand new" Tair 3s falls apart

[strudelj]

I have bought (obviously used ) Tair 3s lens and first time I held it in my hand and turned the focus knob to extend the lens, the lens felled apart. I am posting several images to show the problem. It seems that the rack should have some kind of stopper on the end to limit how far the pinion should turn. Maybe the stopper should be somewhere inside the body of the lens, but my lens is missing it. I have been struggling with the lens whole weak to figure it out why the lens falls apart and how I can put it together.

Well in the start the lens is completely retracted as seen in the figure below. I guess it is focused to infinity or even beyond infinity, please somebody correct me.



When I turn the knob and the lens extends everything works OK until it reaches the position near 3m and the I can hear how the aperture mechanism snaps and then the lens “jumps” out of the lens body. The aperture inside the lens fully closes.

The lens just before the snap



And after the snap



Fully closed aperture …



...although the mechanism in the lens body is set to f4.5



Lens in two parts



The lens aperture mechanism



If I want to put the lens back in I have to move the aperture mechanism inside the lens body to f22 …



and press the aperture release pin and then I can put the lens back again. Then I can fully open the aperture.

Anybody knows how I can fix the lens. Any ideas?



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[Jethro Tull]

Have you seen this.
http://forum.mflenses.com/tair-3-300-4-5-part-of-the-photosniper-repair-guide-t27056.html
it might show you how to sort the rack, your lens looks in great condition too so shame it has dropped apart

[strudelj]

[balibm]

just got mine two weeks ago and had the same problem like you strudelj, mine fell apart as well and i had no infinity. took it apart and after playing with the focusing knob and realized how it works i managed to set it so that it does not fall apart that easy and infinity is fine as well. the focusing rail had to be reversed in mine, focusing knob readjusted, now showing correct numbers and reaches infinity physically. not a lot of effort was put to repairing it and if you dealt with good old Helios-es it should not be a problem fixing it. it just requires more patience possibly when the two large bits are not willing to slide together.



just need to get a 3/8 to 1/4 adapter screw and it wont be embarrassing any more to mount it on a tripod like that above
first impression seeing the pictures taken with it is that its sharpness is not a lie at all