Rangefinder gunked up...

explody pup · Oct 8, 2006

So I finally got the guts to dissect the Petri Automate rangefinder I bought at a garage sale for $1. The shutter would sometimes work at the highest speed, but jam up at lower speeds. Someone on another forum told me this is most likely due to it having 50 years of crud built up in the mechanics.

So, now I have the shutter system completely removed from the rest of the camera. I have written down the order I removed bits and pieces, then taped the small items next to the note so I don't lose anything. I'll be able to get it back together easily. Only problem is cleaning it, which leads me to my question...

How the *@#!% do I clean this:

Is it as simple as soaking it in a light solvent like rubbing alcohol and oiling the gears? What about the shutter? There seems to be a lot of oil on the shutter leaves already. That coupled with the scratches all over the lockrings and screws plus the non-matching leatherette leads me to believe someone had it apart before and over-oiled it.

Any help would be greatly appreciated.

Mitica100 · Oct 9, 2006

EP, do me a favor and go buy a bottle of Ronsonol from the smoking section of any convenience store or grocery store. Either that or buy a flask of Naphta at the local Hardware store. Then choose a container where you can place the shutter with no lens and some Naphta (or Ronsonol, same thing, really). Make sure you cover it with the liquid. Leave it there for 15-20 minutes, continually agitating the container so the grime gets lose. Take out, blow some compressed air onto the mechanism (not from very close and do NOT blow on the shutter leaves or the aperture leaves!!). Repeat the operation, let dry. Now you should have a fine working shutter. Good luck with it. BTW, it's inflammable, so take necessary precautions.

Mitica100 · Oct 9, 2006

Oh, BTW, camera shutters were made so they didn't need any oiling. Do not put any oil on anything.

Mitica100 · Oct 9, 2006

And one more thing... Congrats on having the guts to dissect a shutter! It's a very hard operation but very rewarding at the end.

explody pup · Oct 9, 2006

Wow, that's it? Excellent. Well, I'm off to the hardware store. Thanks Mitica. I'll post an update when I'm finished, and probably more questions as I continue resurecting this camera.

Mitica100 · Oct 9, 2006

explody pup said:
Wow, that's it? Excellent. Well, I'm off to the hardware store. Thanks Mitica. I'll post an update when I'm finished, and probably more questions as I continue resurecting this camera.

That's really it. Let me know the results.

explody pup · Oct 11, 2006

Update: Well, I followed your directions and soaked it in naphtha. Everything worked while it was still wet w/ the solvent but the shutter release would fail to fire once it started to dry out. Maybe 1 out of every 10 times. This didn't change after letting it dry out completely.

Nevertheless, I reassembled the lens hoping that the problem was just a slightly sticky shutter and would work itself out. I don't know if I have over tightened the fittings, but now the shutter opens slow and fails to close completely. I tried loosening some parts which only resulted in parts of the lens shifting where it wasn't supposed to and no change in the shutter's operation. The lens is still detached from the camera (it's fixed-lens, by the way).

So I'm stumped. I might try disassembling it again and cleaning some more as it looks like there's still a film on the shuttes and aperature. But that's about all I can think of to do.

Anyone have any suggestions?

Mitica100 · Oct 11, 2006

explody pup said:
So I'm stumped. I might try disassembling it again and cleaning some more as it looks like there's still a film on the shuttes and aperature. But that's about all I can think of to do.

Anyone have any suggestions?

I might try to leave it in Naphta overnight. The 'film' shouldn't be there, I assume someone put some kind of oil inside and when the Naphta evaporated it left a film of the old oil.

Naphta cleans very well all metal parts and it should free your shutter from all the gunk and debris. Are there any mechanical parts that are slightly bent, perhaps? Like little levers and rods? Are all the little springs in place and functional?

explody pup · Oct 11, 2006

Mitica100 said:
I might try to leave it in Naphta overnight. The 'film' shouldn't be there, I assume someone put some kind of oil inside and when the Naphta evaporated it left a film of the old oil.

Naphta cleans very well all metal parts and it should free your shutter from all the gunk and debris. Are there any mechanical parts that are slightly bent, perhaps? Like little levers and rods? Are all the little springs in place and functional?

As near as my limited experience can tell me, everything looks fine. However, I noticed that the self-timer lever wouldn't budge so I'm suspecting I didn't put it back together correctly. I hope I haven't damaged anything.

I'll leave it in the naphtha bath tonight. Thanks!

explody pup · Oct 12, 2006

'Nother update:

Let it sit in the naphtha over night and took it out to dry after I got home from work. At first I'd cock the shutter and it would release exactly how it was supposed to. After messing around with that for a bit, I noticed that the timer-lever would not budge. I put a little pressure on it, not enough to bend or break anything, and it still would not move. I tried firing the shutter again and it failed in the same manner it did before.

So I'm convinced this isn't dirt buildup anymore. Something is wrong, mechanically. Therefore, way out of my ability to fix. So I dunno what to do. I can't really justify sending this off to get fixed since the camera isn't worth nearly as much as it would probably cost to fix and it's way to complex for me to tackle. Plus, there is very little in terms of documentation for this camera online, so I'd be doing it blind.

Gah.

nealjpage · Oct 12, 2006

You can always just put it back together and put it on a shelf as a conversation piece.

Mitica100 · Oct 13, 2006

EP, sorry to hear it's not working...

It's expensive to repair it so I agrre with neal's idea, have it as a conversation piece. I have many a camera on my shelves due to their 'beyond repair' state of affairs. I mainly buy them broken and if I can fix them, ok, if not, they are for display only.

On the other hand, there is a shop in California called Flutot's Camera Repair (Google it), the shop owner's name is Carol, and she does a great job on cleaning and restoring shutters. She cleaned a pro shutter for my 4x5 and made it like new. Amazing! But it's like $50 for cleaning and repair, if needed, is extra. Plus shipping...