The AM 617 is a relatively modern constructed and well made cylinder movement of the late time of movements with cylinder escapement.Video on YouTube
With 10 jewels, a cylinder movement has got its full equipment with rubies - so on this movement, too. In theory, you could add two additional jewels to the minute wheel, but until now, I’ve never seen such a cylinder movement.
Cylinder movements were build until the mid of last century. Compared to lever movements, they were cheaper and simpler, since they contained one less moving part - the lever . The disadvantage of there movements were, that the sharp teeth of the cylinder wheel always were in contact with the balance cylinder, thus breaking a little bit. On wear of these teeth and on magnetizing, it was soon stopped.
Besides this, cylinder movement were rather inprecise - a daily rate of one or two minutes per day was not unusual.
The AM 617 is one of the few small cylinder movements, which already used a yoke winding system. This is remarkable, since it means, that a rather cheap movement got a rather expensive winding system.
In terms of quality, this is very positive!
At position “9”, you see the T-shaped escapement module, which consists of the balance bearing on the dial side and the balance cock as a unit. This constructions allows a precise depthing setting of the balance cylinder into the cylinder wheel, which is required for reliable function.
At “1”, you can see the “Ebauches Trust” hallmark.
|Number of jewels:||10|
Nickel anular balance|
|Balance bearing / direction hairspring:||Clockwise|
|Adjust mechanism:||Long regulator arm|
|Construction type:||solid construction|
|Winding mechanism:||yoke winding system|
|Setting lever spring:||3 hole(s)|
|Size:||8 3/4''' (measured: 19,1mm)|
Flume: 1947 97|