Did I kill my Biometar?

frenched · Expire: 2014-06-17

I searched around a bit but couldn't find an answer, so I'll put this out to the intelligentsia here.

In an effort to loosen up a sticky focus ring on a Biometar 80mm a well-intentioned idiot who'll remain nameless -- well ok, me -- disassembled the lens for re-greasing but separated the helicals without marking the position. I spent a couple hours trying to put it back but couldn't. My somewhat-local repair guy wouldn't touch it, saying it would be cheaper at this point to just buy another one. He may be right but I'm not giving up yet.

Any thoughts about this? (Besides coming to my senses and giving up lens repair.) Is there a trick to re-joining these parts or is the Biometar toast? This is the silver/aluminum version in Exakta mount and a very nice copy, so I'd really like to save it.

Thanks for any advice!

fermy · Joined: 17 Feb 2012 Posts: 2877

What has come apart could be put together again. All helicals are somewhat similar, it will take time to find correct entry points, but it's definitely not an impossible task. You might try joining two part helical from the other end, it could be easier.

guardian · Joined: 18 Mar 2009 Posts: 1747

I agree with fermy.

First, allow me to say I am Embarassed

(embarrassed)

But I confess I never mark helicals. I guess this is wrong. But reassembly, while occasionally a bit tedious, is never a problem in the end.

My view: In this matter, patience is a virtue.

If you decide, regardless counsel here, instead to deep six the lens, I hope you put the parts up for adoption. I suspect there will be takers!! Smile

visualopsins · Expire: 2021-06-22

On the few (3 or 4) lenses I have taken apart helical I didn't make any markings. On all these lenses made in Japan, the start point is actually already "marked" -- some other lens barrel marking also marks the helical start point. On two lenses the "mark" happened to also be the distance line on the lens barrel.

Properly positioning two helical is exponentially more difficult, unfortunately. My approach could take weeks or might work first time. I say weeks because when something like this frustrates me I set it aside to work on later, whenever I have a few minutes to try again.

Attila · Expire: 2021-11-18

Biometar is not a piece of cake, I did assembled wrongly too, it was complette, but no infinity. Had to pay for repairman to fix it.

inombrable · Joined: 20 Mar 2012 Posts: 545 Location: Salamanca, Mexico

Agree with Fermy too.

I also have disassembled a good number of lenses and not marked the helicals (well marked with not so permanent marker) and put them back correctly. At the beginning you might think you have tried all the possible combinations but .... you haven�t !!!!

This is a matter of trial and error and LOTS of patience, the longest it took me to put one lens back together was almost 3 weeks of trying almost daily !!!!! I was about to bin it for mental health!!!

Up to you but I wouldn't give up on that lens just for that.

Good luck.

frenched · Expire: 2014-06-17

Well I'm relieved to hear all may not be lost. Not too concerned about losing infinity but I'd rather not.

Right now it has a special place on the kitchen counter and every now and then I give it a try when I pass by. The repair guy said something about 24 possible entry points, just have to hit the right one.

SonicScot · Posted: Mon Jun 24, 2013 4:33 pm Post subject:

frenched · Expire: 2014-06-17

I can get the threads to mate and turn a few millimeters but then the helical locks up. I believe I found and tried all the starting positions. I'm beginning to think the threads are crossed/damaged which is probably why the focusing was so stiff in the first place. I don't have a loupe but the first few courses of threads in the aluminum barrel look a little ragged.

guardian · Joined: 18 Mar 2009 Posts: 1747