Just documenting a fix that I didn't really see anywhere...
My 500CM has been inactive for a decade or so and recently got it out and ran a test roll through it. All was well, except the waist level finder. The magnifier just didn't want to pop out and stay put like it should, eventually it just always stayed deployed. And also the latch for the finder itself wouldn't stay collapsed.
Investigating, it appears the little metal tab that engages and holds the finder in the down position had broken off. And since that holds the spring that "closes" the latch that holds the hole finder down... that's why the finder wouldn't stay folded down. And the broken piece and spring were missing... must have flopped out while I was finishing my test roll. Oh well, I thought, I'll have to get me a new finder. That is... until I looked at how much they cost... holy smokes, they are pricey! Also, this whole metal tab latch design seems a little prone to failure over time.
I didn't take pictures of before and after the break, but here's a bit of photoshopping to show what it's supposed to look like, and what mine looked like broken.
So... tried creating a little piece ABS plastic (3D printed) to epoxy into place and serve as a replacement tab and spring holder. Trick was getting the dimensions just right so it can engage and release. The answer was to put a little dab of paint on the rubber nipple and pressing it down... leaving a witness mark on the sliding base, then I could trial and error the dimensions of the plastic part until the tab projected correctly over the nipple witness mark. There was a little bit of the tab sticking up that I could use to register the plastic (slipped into the hole in the bottom of the plastic), so I could get it positioned consistently, and also maybe gave the epoxy a little something to grab onto. I scuffed the metal underneath the plastic part as well. Probably took me 3 or 4 revisions to get it right. Also had to take care to not get any epoxy between the sliding plate and the finder top, as obviously that would be bad. Also had to fashion a new replacement spring.
It actually works... finder magnifier and closing actually work better than I ever remember them working. I think my new spring is a little stronger than the old one, and maybe the old one had been gradually failing for years.
My 500CM has been inactive for a decade or so and recently got it out and ran a test roll through it. All was well, except the waist level finder. The magnifier just didn't want to pop out and stay put like it should, eventually it just always stayed deployed. And also the latch for the finder itself wouldn't stay collapsed.
Investigating, it appears the little metal tab that engages and holds the finder in the down position had broken off. And since that holds the spring that "closes" the latch that holds the hole finder down... that's why the finder wouldn't stay folded down. And the broken piece and spring were missing... must have flopped out while I was finishing my test roll. Oh well, I thought, I'll have to get me a new finder. That is... until I looked at how much they cost... holy smokes, they are pricey! Also, this whole metal tab latch design seems a little prone to failure over time.
I didn't take pictures of before and after the break, but here's a bit of photoshopping to show what it's supposed to look like, and what mine looked like broken.
So... tried creating a little piece ABS plastic (3D printed) to epoxy into place and serve as a replacement tab and spring holder. Trick was getting the dimensions just right so it can engage and release. The answer was to put a little dab of paint on the rubber nipple and pressing it down... leaving a witness mark on the sliding base, then I could trial and error the dimensions of the plastic part until the tab projected correctly over the nipple witness mark. There was a little bit of the tab sticking up that I could use to register the plastic (slipped into the hole in the bottom of the plastic), so I could get it positioned consistently, and also maybe gave the epoxy a little something to grab onto. I scuffed the metal underneath the plastic part as well. Probably took me 3 or 4 revisions to get it right. Also had to take care to not get any epoxy between the sliding plate and the finder top, as obviously that would be bad. Also had to fashion a new replacement spring.
It actually works... finder magnifier and closing actually work better than I ever remember them working. I think my new spring is a little stronger than the old one, and maybe the old one had been gradually failing for years.