How big of the mechanical difference are the 1st-2nd & 3rd Gen Nikon FM?

[MFstooges]

My 2nd gen Nikon FM (two knurled) bites the dust and the shop tech said he would not bother repairing it. He said he has to remove the mirror box to access the suspected part and if it is worn out he can't get a new or NOS replacement part anyway. Furthermore he explained that on the 3rd gen FM (one knurled) Nikon moved that mechanism to be more accessible from the bottom. From what he described the mechanism is the double exposure prevention.
Besides that, Nikon also integrated the shutter lock to the wind lever mechanism on the 3rd gen, so the top cover looks identical except it doesn't have shutter lock. I found a beat up working 3rd gen FM for sale online and I wonder if I can still replace the top cover with the better cover from my 2nd gen. I am thinking I may have to shave the protruding part on the bottom side of the shutter lock on the 2nd gen but other than that what else will make the cover swap impossible?

I know there will be replies like : "just buy a nicer 3rd gen" which I will completely disregard for the sake of tinkering freedom.

2nd Gen

3rd Gen

 

[Andreas Thaler]

My 2nd gen Nikon FM (two knurled) bites the dust and the shop tech said he would not bother repairing it. He said he has to remove the mirror box to access the suspected part and if it is worn out he can't get a new or NOS replacement part anyway.

Of course there are spare parts, they don't have to be new, they just have to be in clearly better condition than the part being replaced.

There are plenty of cameras that can be dismantled, but that is a lot of additional work and costs money.

Another reason to opt for DIY.

 

[ic-racer]

Check with someone else about the repair.

 

[MFstooges]

I completely forgot that I had a 3rd gen FM and I sold it cause I hated the fact that the advance lever had to be opened and poked my forehead. So I cancelled this idea.
Anyway, I opened the camera and fixed it. The cause of the jam was the camera was in half cocked position. I also found the previous repair guy put the wrong shutter button retaining screw and didn't put the small plastic pin on the hot shoe assembly causing it to malfunction.

 

[RalphLambrecht]

My 2nd gen Nikon FM (two knurled) bites the dust and the shop tech said he would not bother repairing it. He said he has to remove the mirror box to access the suspected part and if it is worn out he can't get a new or NOS replacement part anyway. Furthermore he explained that on the 3rd gen FM (one knurled) Nikon moved that mechanism to be more accessible from the bottom. From what he described the mechanism is the double exposure prevention.
Besides that, Nikon also integrated the shutter lock to the wind lever mechanism on the 3rd gen, so the top cover looks identical except it doesn't have shutter lock. I found a beat up working 3rd gen FM for sale online and I wonder if I can still replace the top cover with the better cover from my 2nd gen. I am thinking I may have to shave the protruding part on the bottom side of the shutter lock on the 2nd gen but other than that what else will make the cover swap impossible?

I know there will be replies like : "just buy a nicer 3rd gen" which I will completely disregard for the sake of tinkering freedom.

2nd Gen
View attachment 384962

3rd Gen
View attachment 384963

as a side question: Isn't it easier to identify the generation number by the first digit of the serial number?

 

[MFstooges]

as a side question: Isn't it easier to identify the generation number by the first digit of the serial number?

I personally find it harder to remember numbers, thanks to smartphone.

 

[RalphLambrecht]

I personally find it harder to remember numbers, thanks to smartphone.

There is nothing to remember;just read it off the camera body.

 

[Chan Tran]

I am selling what you call a 3rd gen FM here on the UHH.

 

[MFstooges]

There is nothing to remember;just read it off the camera body.

Then what?

 

[M-88]

Whatever difference there is between the older and newer FM, is nicely covered in its repair manual, which features them both. There's plenty of difference all around the device, but I don't remember the specific part you're interested in. I should have a pdf of that manual somewhere on my hard drive.