====== Rolex 5035 ======
**Cal. 5035** (and the similar **Cal. 5055**, **Cal. 5235**, and **Cal. 5255**) were [[quartz movement]]s produced by [[Rolex]] between [[1977]] and [[2003]].

===== History =====
Rolex was part of the consortium that created the [[Swiss]] [[Beta 21]] movement, which Rolex sold as Cal. 5100 in the limited-production [[Rolex Date 5100|Date 5100]] watch. But even while supporting the [[Centre Électronique Horloger]], Rolex began investing in their own movement operation. As early as [[1971]], Rolex hired René Le Coultre to direct their efforts to design an appropriate movement for a new generation of Rolex quartz watches.

The resulting Cal. 5035 and Cal. 5055 (day/date) were launched in [[1977]] in the [[Rolex Oysterquartz]] watch. These would remain in production until [[2003]] with no direct replacement, as the first and only Rolex quartz movements. 105,097 examples of Cal. 5035 and 5055 were produced over a period of 27 years.

Cal. 5035 was round and well-finished in the Rolex tradition. The plates were decorated with [[Geneva stripes]] and were fully-jeweled for a quartz (11 jewels). Cal. 5035 measured 29.75 mm in diameter and 6.35 mm thick and included central hours, minutes, and seconds as well as a [[date]] complication. The similar Cal. 5055 added a [[day]] function and measured 7.11 mm thick. Many components of this movement are shared with the contemporary [[Rolex 3035|Cal. 3035]] family.

The movements used a forked quartz resonator operating at 32 KHz. This component was initially produced by NDK in Japan, but Rolex later sourced it from Statek, who had an agreement with [[ETA]] to produce these elements in [[Grenchen]], [[Switzerland]]. In this way, Rolex was able to bring production of this critical component back to their homeland. The integrated circuit was a CMOS type and was supplied by [[Ébauches Électroniques Marin]] and the motor was produced by [[Fabriques d'Assortiments Réunies]]. Even the batteries were constructed in Switzerland by [[Renata]].

Cal. 5035 does not use a stepper motor as on current quartz movements. Instead, it has an [[anchor]] style [[pallet wheel]] that ticks once per second. This gives it a very smooth seconds hand despite the [[dead beat]] seconds.

These movements were certified as electronic [[chronometer]]s by the [[COSC]] and were extremely accurate. The movements were adjusted to under one minute per year. They also employed an analog thermocompensation circuit, allowing it to remain accurate as temperature changed.

==== Cal. 5235 ====
Rolex began work on a second-generation movement, Cal. 5235 and Cal. 5255, but these were never produced. They would have been almost entirely new, measuring 28.10 mm or 29.90 mm in diameter and 5.40 mm or 5.80 mm thick and adding digital frequency tuning, a stepper motor, and a new battery. This would allow Rolex to compete with the best next-generation quartz movements but the company decided not to pursue this direction.

==== Cal. 5335 ====
Rolex apparently also developed a [[perpetual calendar]] quartz movement for a next-generation Oysterquartz model that was never produced. Cal. 5335 and Cal. 5355 (day/date display) had 23 jewels and the calendar mechanism was adjusted using only the crown.

===== See Also =====
  * [[Beta 21]] - The basis for the predecessor Rolex Cal. 5100
  * [[Rolex 6620]] - The only other quartz movement from Rolex


{{tag>Quartz_movements Rolex_calibres}}