Service: Nelka With AS 984 Movement

 In Watchmaking

This is another one of those obscure watches from the 40s. According to Mikrolisk, Nelka is a Swiss brand from Biel but I’d never heard of it.

The movement is the AS 984. It did run but it had a very feeble amplitude and it didn’t keep good time.

The chrome plated case is worn, especially on the sides and the lugs but the dial still looks very fresh. The blue hands are also a nice touch and they make the watch look different from other watches with the same style.

Disassembly

Remove all power from the mainspring before you start working on the movement. If you don’t, you might damage the pinions of the wheel train.

Move the click away from the ratchet wheel while slowly letting the crown slip between your thumb and index finger. I always use a peg wood to move the click away from the ratchet wheel and lock it into place.

Remove the balance and the pallet fork with the pallet cock and store them somewhere safe. A lidded tray works just fine.

Nelka with AS 984 movement

The balance, pallet cock, and pallet fork removed

As you can see, the AS 984 has a separate escape wheel cock. Lift the wheel-train bridge and the escape wheel cock.

Remove the ratchet wheel and the crown wheel. This will make it easier to lift the center wheel.

Be careful. The AS 984 has two left-handed screws although they’re not marked as such. Right is loose in this case. Don’t try to remove the ratchet wheel screw the usual way because it’ll snap.

If you’re lucky, you’ll be able to remove the broken bit from the barrel arbor. If Lady Luck isn’t on your side, you’ll need to find another barrel arbor and screw from the pile of parts or order new ones.

Remember to unscrew it the right way and prevent all that.

Nelka with AS 984 movement

Escape wheel cock, wheel-train bridge, ratchet wheel, and crown wheel removed

Take out the escape wheel, the fourth wheel, the third wheel, and the center wheel.

Remove the barrel bridge and take out the barrel.

Nelka with AS 984 movement

Top plate completely empty

Flip the movement around to work on the bottom plate.

Nelka with AS 984 movement

You can clearly see the spider web rust on the set lever spring and on the return bar or yoke underneath

Remove the motion works and the keyless works.

It looks like this AS 984 has had some moisture in the keyless works. Both the set lever spring and the return bar/yoke are heavily tarnished.

Nelka with AS 984 movement

The return bar underneath the cover plate of the set lever spring is even more corroded

Pre-clean the pivot holes and bearing jewels with a peg wood. Don’t forget to remove the bottom balance end piece.

Clean all the parts in the watch cleaning machine.

Nelka with AS 984 movement

It’s not clear on the picture but there was a thick layer of grease on top of the entire mainspring. It’s also an older (blue) type of mainspring without the S-curve and the bridle looks funny. I ordered a new mainspring to replace it

Assembly

Lubricate the bottom balance end stone and install it.

Fit the barrel (with the new mainspring), the escape wheel, the fourth wheel, the third wheel, and the center wheel in position.

Install the escape wheel and then the wheel train bridge.

Nelka with AS 984 movement

The barrel, the wheel train, wheel-train bridge, and escape wheel cock reinstalled

Install the barrel bridge, the crown wheel, and the ratchet wheel. Don’t forget the crown wheel ring.

Move the barrel from the side with a peg wood to test the wheel train. Every wheel should move freely and without much effort.

Turn the movement around and fit the motion works and the keyless works.

Nelka with AS 984 movement

The bottom plate looks much better with the new return bar and set lever spring

Flip the movement to the top plate and reinstall the pallet fork. Wind the watch a couple times to test the escapement. The pallet fork should snap to the other position with the lightest touch.

Place the balance in position and enjoy watching the movement come alive.

Place the hour wheel and washer in position, fit the dial and continue with casing the movement.

Lubricate the outside of the pendant tube with KT-22 grease. Winding and setting the time will be much smoother and also it’ll slightly improve water resistance.

Nelka with AS 984 movement

What do you think of this Nelka? Let me know in the comments below.

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Showing 2 comments
  • Martin Lee
    Reply

    You`ve done a great job on that -as usual Melvin.
    I`ve never heard of that brand either but the dial styling and condition- and the nicely styled lugs make for handsome period piece.

    • Melvin Hollenberg
      Melvin Hollenberg
      Reply

      Thanks, Martin. As you know, there are tons of watches like this one waiting for a collector to give them a second chance. I like those blue hands and I love that loud sound of older movements.

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