8900 movement barrel question

Ultraman Zoffy · Nov 22, 2024

I have a question regarding the barrels in my Planet Ocean (8900 movement).

When I wind the watch I can see both barrel ratchet wheels (the silvery gear circles) rotate, however only barrel one (the left dark gear circle) rotates. Barrel two (right dark gear circle) does not rotate no matter how many turns I give the crown (even though as I mentioned, the ratchet wheel rotates). There is no problem with the timekeeping, in fact it's spot on, but I do sometimes feel the power reserve is not quite 60 hours. Is this normal? This is my first dual barrel watch so I don't know exactly what to expect, so any info would be very appreciated. Thanks!

Gruesome · Nov 23, 2024

Archer's posts in this thread explain how it works. (Ignore the other poster.) The winding crown drives the outer teeth on barrel 1, this starts winding spring 1, as soon as there is a bit of torque on spring 1 the ratchet wheel (connected to the other end of spring 1) on barrel 1 drives the intermediate wheel, which drives the ratchet wheel on barrel 2, which winds spring 2 (whenever the current torque transmitted from spring 1 is larger than the intermediate friction plus the current torque from spring 2), and the outer teeth on barrel 2 drive the train. To see barrel 2 (the outer teeth) move you'd have to watch the running movement for a good while.

Ultraman Zoffy · Nov 23, 2024

Gruesome
Archer's posts in this thread explain how it works. (Ignore the other poster.) The winding crown drives the outer teeth on barrel 1, this starts winding spring 1, as soon as there is a bit of torque on spring 1 the ratchet wheel (connected to the other end of spring 1) on barrel 1 drives the intermediate wheel, which drives the ratchet wheel on barrel 2, which winds spring 2 (whenever the current torque transmitted from spring 1 is larger than the intermediate friction plus the current torque from spring 2), and the outer teeth on barrel 2 drive the train. To see barrel 2 (the outer teeth) move you'd have to watch the running movement for a good while.

Thank you very much; that was very helpful! 👍

8900 movement barrel question

Ultraman Zoffy

Gruesome

Ultraman Zoffy

Similar threads

321 movement Barrel and train wheel bridge question

Omega 8900 movements, reliability and ease of service

Common Faults - Omega 861 Movement - Barrel Bushing

Dual Barrel Movement

Is the 8500g movement the same as 8900 movement?

Basic watchmaking tips - Oiling Part 2 (the mainspring barrel)