Ronda 9035-21

 
Ronda 9035-21

Ronda 9035-21

Description

Although Ronda was mainly famous for their pin lever movements of better quality, they produced also a number of true pallet lever movements, signed “RAX”.

The Ronda 9035-21 with its diameter of only 8 3/4 lignes (19.3mm) is a movement for ladies’ watches. It debuted in the early 1970s and was used for roundabout ten years.

base plate

base plate

The base plate of the red-golden toned movement shows, that we have a Roskopf-like construction, and that is a very well executed movement, where all important bearings contain rubies.

The way, the rubies are set, is odd, since the rubies are pressed into square holes of the base plate.

gear train

gear train

The gear train is a mix between Roskopf and conventional lever movement, since it contains a directly driven center second.

The mainspring barrel drives the second wheel, followed by third wheel, center seconds wheel and finally the steel escape wheel.

side view of the gear train

side view of the gear train

The two leg anular balance, which beats already with 21600 A/h on the version with suffix “-21” is protected against shocks by two KIF Protechoc bearings.

It’s exact frequency can be adjusted on the hairspring key only.

As escapement, a swiss pallet lever escapement is used.

double cannon pinion

double cannon pinion

The double cannon pinion contains a slipping clutch. The lower part engages, like on Roskopf movement, with the mainspring barrel, while the upper part engages with the hands setting wheel.

At least here, you can no longer take of a true Roskopf movements, since there, the hour wheel would also have been driven by the mainspring barrel and not by the hands setting wheel.

date switching wheel

date switching wheel

On its lower side, the date switching wheel has got a moveable finger. Normally, it is a bit longer than the other teeth and advances the date ring.

Turning back the hands, the date correcting mechanism, which consists of a moveable star wheel and is driven by a changer wheel, ensures, that the date ring is turned forward quickly.

When the long finger of the date switching wheel would engage with the date wheel, which is not wanted here, and so, because it is moveable, it can just move out of position and let the date ring slip through.

open calender mechanism, yet uncovered

open calender mechanism, yet uncovered

This pretty complex calendar mechanism is equipped with well flyable spring and not too easy to service.

Ronda 9035-21: Dial side

Ronda 9035-21: Dial side

The flying parts are covered, so that the operational safety of the calendar mechanism is ensured.

In the lab

The specimen shown here came dirty and with visible water damage into the lab and got a simple service.

Timegrapher result

The rates are not very good. Maybe it’s because of the water damage, maybe it’s because of age and wear. In Average, the large rate differences will more or less neutralize each other.

horizontal positions
dial up +13 s/d 288° 0.1ms
dial down -21 s/d 310° 0.0ms
vertical positions
crown right (12 up) +40 s/d 242° 0.9ms
crown up (3 up) +46 s/d 243° 0.4ms
crown left (6 up) -1 s/d 246° 0.1ms
crown down (9 up) +26 s/d 246° 0.6ms

Technical data

Manufacturer:Ronda
Caliber:9035-21
Size:8 3/4''' (measured: 19,3mm)
A/h:21600
Number of jewels:17
Escapement:Pallet lever
Balance types: monometallic anular balance (two legs)
Shock protection(s): KIF Protechoc
Balance bearing / direction hairspring:Counterclockwise
Moveable stud:yes
Adjust mechanism:Hairspring key
Construction:
  • lever
  • escape wheel, seconds wheel, third wheel, large driving wheel
  • mainspring barrel
Construction type:solid construction
Winding mechanism:yoke winding system
Setting lever spring:4 hole(s)
Features:
  • SCD (direct center seconds)
  • QG (date indication (aperture))
  • RDR (date corrector)
References: Flume: K3 N1 21
Inventory number:21014

Usage gallery

Meister-Anker ladies' watch

Meister-Anker ladies' watch