Pentax-A spring missing

nrparsons · Posted: Thu Apr 28, 2011 3:39 am Post subject: Pentax-A spring missing

I received a Pentax-A 50mm f/2 on which automatic aperture does not work because the tiny spring is missing from beneath the aperture contact pin. Does anyone know where I can get a replacement spring?

David · Expire: 2013-01-25

Get a couple old computers off eBay and take the hard drives and disk drives apart. Preferably, get computers with floppy disk drives as they have more small springs. The HDDs will also have internal springs, or should. But they also have VERY POWERFUL magnets, so don't work on this next to your good computer or your watch. Or your credit cards.

aleksanderpolo · Joined: 24 Jan 2010 Posts: 684

Amazon has them, but first, go to Smallparts.com and search for the specific size, and then you can buy them on Amazon.

Lloydy · Expire: 2022-01-01

Disposable cigarette lighters have a long small spring under the flint that is ideal for cutting to shorter lengths.

nrparsons · Posted: Thu Apr 28, 2011 8:29 pm Post subject:

Thanks to all for these suggestions. I didn't think of an old computer for springs. As it happens, I have two of them to tear apart.

sinhas · Joined: 07 Apr 2009 Posts: 13 Location: USA

If you do not find one let me know. I bought some useless lenses just for this. I will just mail you in a letter. I will check tonight what kind of spring is that. I will say its not worth buying a new spring for this, you can probably find the 50/2 cheaper on craigslist.

nrparsons · Posted: Sat Apr 30, 2011 2:37 am Post subject:

Thanks, Sinhas. That's very generous of you. Let me know if you find a spring and I'll PM you my address.

I have another A 50/2 that works perfectly, but I'm reluctant to take it apart to measure the spring because I'd probably lose the spring--or the aperture ball bearing or something else. Yes, I know about the plastic bag trick, but believe me, if there's a way I can lose a small part, I will.

If I don't find a replacement spring, it's no big deal. The lens works okay fully manual. I'd hoped to be able to get it in salable shape, though.

sinhas · Joined: 07 Apr 2009 Posts: 13 Location: USA

Parson, I do not have a non-functional 50/2 exactly, but have some other lenses here there, so hope one may be compatible. I do not know what kind of spring is that. I tried to open my m-50/2 to see it but could not see after opening the back mount and removing aperture ring. I stopped there and did not go any further. If you know the spring, you can PM me with diagram/picture and approx size. I will see if any in my stock matches there.