Checking your heart function with the 'Ricoh pin'.


Link Posted 18/08/2021 - 15:27
I recently acquired a few cheap old lenses, largely via eBay. Well, you never know, one might be a gem. One was a pure gem alright, but not in a good way. The first two went on my K5 fine and functioned OK. The last was a Sirius 135mm f2.8. Something didn't feel quite right when it went on. something definitely felt quite wrong when I tried to remove it, because I couldn't! To cut a long story short, after exhausting my considerable store of expletives, I started research on 't web and discovered the 'Ricoh pin', a design I feel was implemented by someone who still held a massive grudge about the result of the last war. After huge amount of buggeration with feeler gauges to no good effect I considered the relative values of repairs and replacements and decided to resort to brute force, one of many recommendations. It worked. The camera has been tested with other lenses already long in my possession at everything is fine. Does anyone know how to fix that damned pin?


Link Posted 18/08/2021 - 16:06
Sdeve wrote:
Does anyone know how to fix that damned pin?

A minute drop of superglue or just push it in with brute force using a fork prong. Both work but the pin will never work again (just a warning incase you need it to for some reason).

BTW, the war reference made me smile.

Brute force got my first one off as well ... only had the camera a few days.
. My Flickr
Last Edited by Mike-P on 18/08/2021 - 16:07

vic cross

Link Posted 18/08/2021 - 16:41
Many moons ago in my film days I bought a Vivitar 24mm f2.8 manual lens. PK-A/R which had the Ricoh pin. All I did was remove 4 little screws on the mount took out the pin and its spring . I had heard about this problem before I used the lens. Just be careful not to drop the little screws. I use a magnetic tray when working on something fiddly.
Born again biker with lots of Pentax bits. Every day I wake up is a good day. I'm so old I don't even buy green bananas.



Link Posted 19/08/2021 - 00:54
Last one I had I put masking tape over the entire lens and took a Dremel grinder to the damn thing - It never got stuck again! (You may have realised by now that I take a very practical approach to problems!).
Both the *istDS and the K5 are incurably addicted to old glass

My page on Photocrowd - link
Last Edited by davidwozhere on 19/08/2021 - 00:56


Link Posted 19/08/2021 - 16:14
You could always sell the damned lens!

I assume that it is an M42 mount, jamming in a PK adapter. Those 'Ricoh' pins are a ruddy nuisance. Sometimes they don't give trouble in a genuine Pentax M42/PK adapter but often jam in other brands. There was quite a long discussion just over a year ago in this group.


Lots of comments, including a note from me describing my earlier problems with a Pentax 28mm M42 and some adapters.

A few of my photographs in flickr.
Lizars 1910 "Challenge" quarter-plate camera; and some more recent stuff.
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