In the 1970ies, Ronda launched their caliber series 10xx/11xx/12xx/13xx, which made out one base caliber (1011) almost two dozen of variations with different features, with pin- and pallet lever and with different beating frequency.
To that series belonged also the Ronda 1017 shown here. It was a pin lever movement with day-date indication, center second and (here) 21 jewels. With a diameter of only 10 1/2 lignes, it beloged to the smallest movements of the series.
The base place shows, that this movement is massive and a pillar construction at the same time. You cannot see more of the construction, only that all important bearings (except the mainspring barrel and the center second) contain rubies. Interestingly, the round deepenings are not concentric with the ruby bearings, which make them look a bit odd.
If you look exactly, you can also see four blind jewels on the outer side of the base plate. None of these jewels has got a technical purpose, but together with the three cap jewels on the movement bridge, the otherwise 14 jewel pin lever movement is transformed into an impressive 21 jewel movement.
The three movemend side bearings of fourth, third and second wheel have got cap jewels, which are mounted in one single platelet. Oddly, the most significant bearing, the escapement wheel bearing, has got no cap jewel!
The gear train of the Ronda 1017 is contemporarily modern with mainspring barrel, second wheel, third wheel, center second wheel and escapement wheel. The gear train is driven on the dial side only by the outer gear of the mainspring barrel.
The anular balance is not shock protected. It still beats with slow 18000 A/h and regulates a pin lever movement.
On the yet empty dial side, you see, that the hands are driven by the mainspring barrel.
For a pin lever movement, it's a bit unusual that it uses a compareatively expensive yoke winding system. It is very elaborate made with the setting lever spring being the setting lever at the same time.
You can also see the four blind jewels beneath the outer edge of the dial plate.
As often, Ronda uses a calendar mechanism with unusual quickset function: At 1 o'clock, there's a moveable star wheel, which only enages with date ring, when turning back the time. It then advances the date. A slippable finger of the switching wheel at 11 o'clock ensures, that no harm occurs, when it simultaneously engages with the date ring during 11 and 12pm.
Imaging, that there's an additional lever at 9 o'clock, which is reponsible for locking the date ring into its proper position. Unfortunately, this lever has got very good flying abilities...
The date correction star wheel at 1 o'clock is held in position by a spring. This spring shall be left (and not right, as on the photo) from the axle.
The lever at 5 o'clock ensures proper positioning of the weekday disc.
The weekday disk has got only one language and covers up the date mechanism.
This movement was donated by Rolf-Jürgen. Thank you very much for the great support of the movement archive!