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Baumgartner 866 CLD DIG

Baumgartner 866 CLD DIGBaumgartner 866 CLD DIG


The Baumgartner 866 CLD DIG, which was launchen probably in the late 1960ies, is one of the most unusual variants of the very popular caliber 866. With a digital hour and minute indication and a calendar, it it maximally equipped. 



As common on Baumgartner movements, this caliber is also a pin lever movement with a Roskopf construction, which means, that the minute wheel is located on the dial side is an driven, like the hour wheel, by a gear on the mainspring barrel, which is connected with a slipping coupling.

Due to this construction, the mainspring barrel can be very large and even overlap the center of the movement, and together with an also large second wheel, one transmission step can be saved.

gear worksgear works

The center second is indirectly driven, 1:1 by the outer teeth of the third wheel, which is located at 3:30 o'clock. There's no flattering or bucking, even without a friction spring.

side view of the gear worksside view of the gear works

The realisation of this movement is very simple; besides the upper balance wheel bearing, there are no bearing jewels, but only simple drillings on the plates. For a watchmaker, it's a bit time consuming to re-assemble the movement, but these cheap movement weren't supposed to be repaired at all.

base platebase plate

The balance, which is equipped with a large finger, beats slowly with 18000 A/h and is on both ends secured with a Novodiac shock protection system. On the dial side, there's a oddity: Instead of using a ruby, a metal plate is used. This is only a few cents cheaper, than using a ruby bearing here, but if many thousands of these movements were sold, the price savings were a bit effective.

empty dial sideempty dial side

On the dial side, when the date ring is put away, you can see the yoke winding system and the two gears on top of the mainspring barrel, which drive the hour and minute wheels at the center of the movement.

dial side view with date mechanismdial side view with date mechanism

The date indication mechanism is very simple: A star shaped wheel at 6:30 is driven by the hour wheel. It containts one longer tooth, which advances the date every 24 hours counterclockwise. The lever with a spring at 11 o'clock (the spring, which can fly very well, is not yet mounted) ensures proper locking of the date disc. There's no quickset possibility for the date.

dial side view with hour display mechanismdial side view with hour display mechanism

The same mechanism in a smaller implementation is used for the hour ring. The interlocked minute wheel drives a switching star at 3:30 o'clock, which also contains a longer tooth and advances the hour ring counterclockwise. There's also a lever with spring to lock the ring. Of course, there's no quickset possibility.

dial side without minute discdial side without minute disc

Here you can see how the dial side looks, when the minute disc is put away, and you can also see the recess for the spring of the minute ring lever.

Baumgartner 866 CLD DIG dial sideBaumgartner 866 CLD DIG dial side

The minute disc doesn't jump but slides, just like a minute hand.


 Technical data

Caliber866 CLD DIG
Number of jewels1
Escapementpin lever
Shock protection(s)Novodiac
Balance cock directioncounterclockwise
Hairspring studfixed
Regulator typeHairspring key
Movement constructionFork
Escapement wheel, Fourth wheel, Third wheel, Center second pinion, Mainspring barrel
Construction typepillar construction
Winding mechanismyoke
Setting lever spring1 holes
FunctionsHour, minute, second, day
Beats per hour18000
Size13,5''' (measured: 30,7mm mm)
Baumgartner 866 CLD DIGBaumgartnerBaumgartner866 CLD DIG13,5'''Baumgartner 866 CLD DIG1 Jewels, 13,5''', 18000 A/h, SCI,QG,DIG


In the lab

The specimen shown here can with water damage (rust on the main plate and axels) in the lab and got a full service (cleaning, oiling and regulation). Due to the lack of tools, no further de-rusting of the gears was done.

On the timegrapher

Only in the position "dial up", the rates are perfect. Interestingly, this is the only position, where the only bearing ruby in the movement is effective. All other position show more or less poor rates, probably due to the water damages.

crown rightcrown right crown topcrown top crown leftcrown left crown bottomcrown bottom 
dial topdial top dial bottomdial bottom 

vertical positions
12 up  -400 seconds/day
3 up  -240 seconds/day
6 up  +120 seconds/day
9 up  -60 seconds/day
horizontal positions
dial down  +70 seconds/day
dial up  -+0 seconds/day
timegrapher measurings

Usage gallery

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