AS1820 Automatic module issue.

[julio933]

Hello! Let me introduce myself. I am Julio from Mexico City. A full time IT Business Manager, but I've found in vintage watch repair an amazing occupational therapy.

This time, I want to ask your advice with an old AS1820 movement and its automatic module. When it moves in counterclockwise, it moves the crown wheel, but  when it moves in clockwise direction, the oscillating mass makes a helicopter effect . It doesn't seem like normal behavior to me, although it does increase the movement load. I've already replaced the reversing wheel, but the new one and the original one that works the same, both cause the same effect. What could be the cause of this behavior? I'm even doubting if it should work like this from the factory, but it seems to me that automatic loading would be very less than optimal.

Thank you in advance!

 

[RichardHarris123]

Hello and welcome from Leeds, England. 

[Marc]

That looks like normal behavior to me.

That movement only winds in one direction, not both, so when the rotor turns anti-clockwise it winds the main spring and so is fighting against the mainspring tension. As a result it will turn under its own weight but it won't free spin. When it turns clockwise though it has no resistance and so can spin freely.