Nikkormat shutter not latching

[Woutervg97]

A while back i received a box with inside an old Nikkormat FT. Back than I didnt know much about repairing, so when the shutter started jamming I opened it up, but gave up.

I reopened it recently to give it a new go. There is a new problem however. When I use the lever, the shutter immediatly fires. I can hear the spring or wheel of the shutter timer buzzing and it closing again when I reach halfway. After that the lever locks up and I have to unscrew the bottom, reach under the shutter and push a little metal latch back so I can use the lever again with the same result. Any guesses of what is going wrong here? I assume the shutter is just not latching, but I dont know where to look for this fix. Im afraid to start openint the front or top and do more damage than good

 

[4season]

Likely a combination of stale, contaminated, lubricants and bits of old moltopren (foam) fouling the mechanism. Mechanical Nikkormats are very well-made, and (relatively) easy to repair. But nevertheless, skill and a considerable amount of disassembly are required.

 

[thinkbrown]

So I haven't pulled apart an FT, but in my FTN I experienced the same issues after the pin on the cam in the winding assembly came loose. It's peened in originally and mine popped out of the cam. I reseated the pin, soldered it into place, and retimed the winding arm which worked out nicely

 

[Woutervg97]

Likely a combination of stale, contaminated, lubricants and bits of old moltopren (foam) fouling the mechanism. Mechanical Nikkormats are very well-made, and (relatively) easy to repair. But nevertheless, skill and a considerable amount of disassembly are required.

For this issue; where would you suggest I start cleaning? Removing the bottom even further or open the front?

 

[Woutervg97]

So I haven't pulled apart an FT, but in my FTN I experienced the same issues after the pin on the cam in the winding assembly came loose. It's peened in originally and mine popped out of the cam. I reseated the pin, soldered it into place, and retimed the winding arm which worked out nicely

Is that a pin present in the bottom?

 

[Woutervg97]

The hook in the middle of the gap is what I have to push back so i can fire it again. I believe the area below the large gear is just the timer, so i wont have to look at that I assume, but maybe I have to open the front to reach the element in the gap?

 

[Woutervg97]

Other thing I just noticed: I had been shooting with the mirror locked up. I remembered that the original problem was the mirror sticking up, so i tried with the mirror lowered. The mirror stays stuck in the upward position after I wind the shutter

 

[thinkbrown]

Is that a pin present in the bottom?

Sorry, totally missed this before. Yeah, the pin is on the winding cam, I've included a photo of mine post-repair.

I'll also note that I had a tricky time getting the brass rack reinstalled in the correct timing. The pinion I circled in red has a bit of backlash in it and it has to be set right up to where it begins winding the shutter before installing the rack, otherwise the shutter doesn't wind correctly.

The lever I circled in blue also has to be in the correct place so it ends up on the winder side of the pin on the rack that winds it. I accidentally installed the rack incorrectly the first time I reassembled it and ended up with that lever not getting cocked.

 

[Woutervg97]

Thanks! I put the red gear towards the winder before assembling and now it locks in place properly! The issue seems to be the shutter not going back into the original position completely. I'm going to attempt a little more cleaning of residue to see if that fixes it.