DIY D7200 shutter replacement + insights

[Øivind Tøien]

The shutter of the F2 also travels horizontally, just checked.
The titanium has a structured pattern, presumably to make it stronger.

[mxbianco]

The shutter of the F2 also travels horizontally, just checked.
The titanium has a structured pattern, presumably to make it stronger.

You are quite right, I had just corrected my statement. There was no room in the body to have two spools for winding the curtains above and below the frame!

More clarification: the F2 shutter had a Hexagon-shaped structure to make it lighter and sturdier and allow shutter speed to 1/2000" (on Nikon F it was limited to 1/1000"). Flash sync was still limited to 1/60" (even on the F3), it was only with the F4 that sync was upped to 1/250" (and top shutter speed down to 1/8000")

Ciao from Massimo

[Bernard Delley]

Wow ! thanks for the interesting detail on shutters.
However the shutter of my Nikon F2, serial 7570445 (bought about 1976), definitely runs horizontally. The image below shows a curtain end reinforcement, which is visible statically when the manual winding action is interrupted. Incidentally the image was taken with AFS 60mm f/2.8 on the repaired D7200 of this thread.

[Bernard Delley]

I believe remembering that the red mark at 1/80 s on the shutter dial indicates the flash sync for the F2.

[Hans_S]

The F2 shutter is very thin titanium. The camera geometry of this horizontally running shutter seems to imply that it is rolled. I would not want to expose this shutter to focused sun light either.
The modern vertical running shutters are descendants of a shutter appearing first in the Nikkormat camera nearly contemporary with the F2. The blades are obviously very thin, surely titanium again. maybe a little thicker, as the must not bend and hold up for hundred thousands of actuations.

Ha, if only this was true of the F2AS I bought new back in 1978. In the first year it, according to the techo that rebuilt it, "tore the rivets out of the shutter". In the third year the shutter again self destructed shortly after I put an MB-3 on the camera. During this period I would have averaged 5 rolls of film per week ie approximately 10k frames per year...hardly a serious workload for a flagship unit. The poor electronics, 4* resistor rings consumed so far, well that's another rant

[Roland Vink]

The Nikon FE2, FA and early FM2 where the first Nikon cameras with a very fast 1/250 sec flash sync speed. The shutter blades had to be very strong and lightweight to move so quickly, the only suitable material at the time was titanium. The shutter blades were very thin and stiffened by thicker sections in a honeycomb pattern. Later Nikon found a way to make aluminium shutter blades which were strong and light enough. Aluminium is cheaper and easier to work, so Nikon switched to them for later FM2 cameras and all subsequent cameras. These shutters don't have the honeycomb pattern. It's possible that if very strong concentrated light is focused on the shutter, and the shutter is black so absorbs most of the heat and the melting point of aluminium alloys is relatively low, it could burn a hole in the blades. However, I wonder if Nikon now uses some kind of plastic for shutter blades as the hole in the shutter blade looks more like melted plastic, or maybe aluminium melts like that too?

[Birna Rørslett]

The sad story about the burned 'shanding' unit of the Z9 does NOT refer to a traditional shutter curtain. The sensor shield is just comprised of tiles made of lightweight plastic and its purpose is to prevent ingress of dust and dirt to the sensor. The Z9 user can opt for the protective shield being activated as the camera is switched off, or deactivate it all together.

By the way, I noticed earlier that the terminology here in the thread is confusing and really leads to mixing up a true shutter [curtain] and the protective shield of Z9, as the Z9 does not have any mechanical shutter at all.

[Bernard Delley]

The Nikon FE2, FA and early FM2 where the first Nikon cameras with a very fast 1/250 sec flash sync speed. The shutter blades had to be very strong and lightweight to move so quickly, the only suitable material at the time was titanium. The shutter blades were very thin and stiffened by thicker sections in a honeycomb pattern. Later Nikon found a way to make aluminium shutter blades which were strong and light enough. Aluminium is cheaper and easier to work, so Nikon switched to them for later FM2 cameras and all subsequent cameras. These shutters don't have the honeycomb pattern. It's possible that if very strong concentrated light is focused on the shutter, and the shutter is black so absorbs most of the heat and the melting point of aluminium alloys is relatively low, it could burn a hole in the blades. However, I wonder if Nikon now uses some kind of plastic for shutter blades as the hole in the shutter blade looks more like melted plastic, or maybe aluminium melts like that too?

Delrin, a high quality plastic, melts at 175 C, aluminum at 660 C and Titanium at 1668 C. I just  cannot believe that the shutter blades of the D7200 would be plastic. By hand feel its foil thickness is between 12.5 micro meter and 50 micro meter. Contrary to the household aluminum foils, shutter blades feel like spring blades. -- Molten metal foil can look like this burned hole.  -- Each D7200 shutter curtain has 4 blades, while the Z9 protective shield appears to have 3 tiles. - I just discovered the pictures of the Z9 sensor shield further down the in the  "Z9 Failure" thread: it is definitely plastic tiles, much thicker, on a single curtain. -- I seem to remember that the Nikonos III shutter was mentioned to be made from aluminum, vertical running. This shutter goes to 1/500s . I still have my Nikonos III,  Each curtain is a single blade. The surface structure is more like the rough side of aluminum foil, however blackened.

[Roland Vink]

Pure Aluminium melts at 660 C, but it is usually alloyed to improve strength and other properties. Most Aluminium alloys melt at significantly lower temperatures, some lower than 500C.

[Akira]

Does the color of the material matter here?  Kitchen aluminum foil is shiny silver and reflects most of the light, whereas the shutter curtain is almost black and isn't very reflective.

When I tried to burn the piece of paper using a hand glass when I was in the junior high, I used a piece of black paper.  A piece of white paper of the same material was slower to catch the fire, if I remember correctly.

[Erik Lund]

Yes, there are many different alloy's with different temperature properties, not a fixed value. Shutter-blades are subject to very high forces so a lot of engineering has gone into material testing,,,

Shiny and reflective blades, would definitely cause issues regarding light bouncing back and forth between the shiny sensor surface and the blades.
 

[Hans_S]

Whilst we might not suffer melting of the aluminium shutter blades, I suspect high temperatures may detrimentally alter the temper of the material and cause buckling of the blade.

In a quick'n'dirty experiment this sunny morning, I cut some 30x40mm sections from a screw-top wine bottle capsule and applied some concentrated sunlight. This aluminium was 0.22mm thick, painted black and quite stiff to bend. Focussing a 8x12cm planoconvex lens on the black surface generated enough heat in a minute to cause slight buckling and obvious annealing of the alloy. Bringing out the big gun (35cm diameter lens from an old 5x7 enlarger) had the second sample heat up in seconds...again no melting but visibly distorted and very soft to bend. So I guess that despite there being no visible damage to an aluminium shutter, overheating may still cause significant issues.

Further to Erik's point about temperature properties, I had a chat with a friend who provides tech support to the bottle closure industry. He stated that the coating/printing on the caps is baked at a maximum of 185deg C as touching even 200 degrees would reduce the temper of the aluminium to the point where it can not be used to shape the cap. So there would appear to be some quite narrow margins in getting aluminium to behave in the manner required.