The AM 612/17 is a relatively modern constructed and well made
cylinder movement of the late time of movements with
cylinder escapement.
The exact caliber name, whether it is AM 612 or AM 617, is not determinable, since
even the Flume Werksucher just lists it as "AM 612/17".
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.
gear construction
Cylinder movement 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.
main plate
The AM 612/17 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!
dial side view
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.
Technical data
Manufacturer
AM
Caliber
612/17
Number of jewels
10
Escapement
cylinder
Balance
Nickel
Shock protection(s)
none
Balance cock direction
clockwise
Hairspring stud
fixed
Regulator type
Long regulator arm
Movement construction
Center second pinion Fourth wheel, Third wheel, Center wheel Mainspring barrel
