Operations carried out

Cameras - lenses - accessories

IMG_1375

Nikon F - Oily

step by step

In “very angry” mode


But how to make it understood that a blocked device, certainly after a bad fall, cannot be repaired with excessive oiling as useless as devastating!!!

This Nikon F has, in addition, already been visited “brutally”!

Parts stuck with superglue which at the same time blocks the screw…

I am curious to know if in the case of a broken down car, they open the hood and throw liters of oil on the entire engine!

Its condition shows significant wear and marks of violent impacts.

The bottom fixing screws were missing and the viewfinder screws were not original.

To disassemble, it is imperative to remove the front sheathing. This is a delicate operation, these sheathings are very strongly glued and they are very fragile.

You have to soften the glue with isopropyl alcohol and lift it little by little without tearing it.

After disassembly, its condition is really pitiful.

Oil everywhere, sand and even the front hook of the viewfinder is bent…

With a good coffee for courage, the degreasing was carried out by a first bath in isopropyl alcohol in an ultrasonic tank.

A second identical bath in new alcohol finished the cleaning.

These baths wet the ribbons and the anti-veils. For a complete drying, a cotton swab was placed, without risk, because the curtains and the ribbons are under tension.

This decision made it possible not to release the tensions in order to check the state of the scrolling times of the curtains and the speeds in the state of this device.

After a minimal lubrication of the mechanisms and a few triggers, it spent the night in peace.

Reassembly of the slow speed mechanism (degreased of course) and a test!

The mechanisms work, but the curtains and speeds must be adjusted.

The settings of 1/500 and 1/1000 are done independently of the other speeds.

After a minimal lubrication of the mechanisms and a few triggers, it spent the night in peace.

Reassembly of the slow speed mechanism (degreased of course) and a test!

The mechanisms work, but the curtains and speeds must be adjusted.

The settings of 1/500 and 1/1000 are done independently of the other speeds.

The self-timer was also blocked and oily.

Degreasing, deep drying, disassembly of the support, unblocking, lubrication only on the pinion bearings, test reassembly, it is functional.

At this stage, this Nikon F is functional again.

FTn viewfinder

It is also very worn, screws that are not original, but especially the needle of the galvanometer which, without batteries, remains stuck in the center.

This is often the case of a galvanometer that has given up the ghost, shocks are never good!!

The second risk with these old viewfinders is that the internal graphite track is very worn by the friction of the brushes.

After disassembly, (be very careful to disconnect the 3 wires before separating the viewfinder into two parts) it is indeed the galvanometer that no longer gives any sign of life…

The only solution is to replace the galvanometer (those of the DP-1 / 11 are not compatible) or, if possible, change the viewfinder.

These old and often used viewfinders require some minor modifications.

On the one hand, the power supply was originally with PX 625 type batteries of 1.35 volts with mercury, now prohibited.

It is therefore necessary to use EPX 625 type batteries which are 1.55 volts.

Some viewfinders with tired electronics support this overvoltage, but it is not recommended.

To compensate for this voltage difference, a Schottly diode can be included between the output wire of the battery container and the circuit.

It is then necessary to readjust the battery tester with the variable resistor located on the top of the viewfinder towards the rear and then the die with the second variable resistor.

There may also be oxidation on the top of the battery container, which, little by little, no longer allows the power supply? As a precaution in the event of disassembly, a layer of varnish protects the surface, the solder and the wire.

The second problem is that the brushes rubbing on the circular graphite track (in gray on the photo) dig tiny grooves that cause the galvanometer to operate erratically.

A “DIY” solution is to very slightly offset the brushes so that they are in contact with a less worn surface of the track. Of course this is only a random solution, but new parts are now impossible to find.

The viewfinder available for troubleshooting was also used.

The upper part of the original viewfinder was kept and only the lower part containing the main elements and especially the galvanometer were changed.

Opening synchronization

Nikon F with Photomic viewfinders require synchronization with the lenses, so that the viewfinders display the maximum aperture.

When mounting the lens, the “fork” of the aperture ring places the viewfinder on f/5.6 which is the zero point corresponding to the measurement at real aperture (example with the 500mm f/8 with fixed aperture or the 35mm PC without coupling with the viewfinder).

The coupling is achieved by the famous “back and forth” of the aperture ring which indicates to the viewfinder that the maximum aperture of the lens is f/1.2 / 1.4 / 2.0 / 2.8 / etc.

This action positions the internal graphite track (which is a variable resistor) in correspondence with the maximum aperture value.

Aesthetic restoration

The main repairs having been completed, the device is functional.

The breakage and especially the absence of the piece must be repaired…

There will be no miracle, but it is better than broken and therefore almost unusable.

The “quick” solution would be for the user to stick a piece of black tape, but this would be very unsightly and would have to be renewed each time the back is removed…

The repair consists of creating dovetails (irondelle tails) in the body of the device in order to retain and reinforce the repair.

A wooden stick surrounded by painting tape is placed in the chicane provided for the back.

Tape delimits the surface to be restored in which synthetic metal is applied.

The setting time for this material is around 30 minutes to several hours depending on the ambient temperature. Complete hardening is between 12 and 24 hours. The device was positioned vertically for the necessary time.

The synthetic metal is completely hardened, it is necessary to proceed with a rough sanding to remove the excess material, followed by a finer sanding to arrive at the shaping.

When sanding, the synthetic material being less hard than the metal, differences may appear. Just add a little material and continue sanding.

If desired, a finish based on putty further refines the aesthetics.

Then, after degreasing, black Cerakote air-drying paint is applied. It is obvious that it is not possible to use a baking paint.

This type of paint has a semi-matte satin finish. To improve the rendering, a coat of Cerakote varnish also air-drying is applied.

Finally, re-glue the sheathing.

Of course, it’s not exactly the same as the original, but it’s better than a broken device…

And then, bodywork is another job! 😉

Nikon Much more than a legend

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