zOwie Omega Discussion Forum

: Would someone please confirm or deny that my Omega Seamaster
: Pro model 2531.80 should be placed on a watch winder to
: wind clockwise.

Tyler earlier asked the same question to Omega. In his case, he was asking about the GMT. But since the GMT's Omega 1128 movement is based ont he same ETA2892A2 that the Pro's 1120 is, this information should apply equally to both.

1) Your GMT caliber 1128 winds up bi-directional.

2) I did not calculate the ratio oscillating weight - barrel (which must be made to have a 100% correct result). But it is known that in a modern watch movement this proportion is about 120-1. This means, that 120 revolution of the oscillating weight produces one revolution of the barrel.

The barrel, to be fully wound up, needs about 7 revolutions. This way, 7 multiplied with 120, gives a result of about 840 revolution (of the oscillating weight). The watch, when is unwind, has to accomplish about 840 full revolutions to be fully wound up.

3) Modern automatic watches, such as Omega caliber 1128 can not be over-winded. The mainspring is a so called slip-spring, which means that the end of the spring that is in contact with the barrel wall slips always a little bit further (un-winds a little) when the energy is too high or before the movement is over-winded.