Since the beginning, Rolex used Aegler’s movements , so the firsts ones were powered by jewelled lever movements from Jean Aegler’s factory placed on Rebberg street which later gave the name to the movement. Rebberg movement was introduced in the early years of this century and was initially available with both lever and cylinder escapements.
In 1912, Hans Wilsdorf convinced of the imminent arrival of the wristwatch, gave Hermann Aegler the largest order the firm had ever received. The Rebberg was produced in two different grades, 15 and 7 jewels. The “Rolex 15 Jewels” model featured an all over machined finished to the plates and featured a main winding wheel.
Later, the Rebberg movement was replaced for the Hunter one which production would run almost twice as long. It was first introduced in 1923 in a 10 – ½” size not being recognizable to most of the people because the center wheel bridge is completely different from the later, a more common version. All Hunter movements have a polished rhodium finish. The initial version of the 10 – ½” Hunter was made in 3 different grades: Prima, Extra Prima and Ultra Prima; all of them with 15 jewel movements. The Hunter was the first Rolex movement capable of being timed to chronometer precision. These, were 16, 17 or 18 jewel movements with capped escape jewels, and always had a “Chronometer” sign on its dial.
In 1935 a new Rolex came up with a new patent, the 188077 model: the Superbalance in which timing adjustment screws were recessed from the external surfaces of the balance wheel. The introduction of the Superbalance produce the abandonment of the three grades previously used. The differences were now in the quality of the jewelling.
A visible way of judging the quality of the movement was by looking at the number of adjustments engraved on the main plate. The simplest movements had only two adjustments while better grade movements could have between five to seven adjustments.
From 1935 to 1969, the company produced two iterations of the same 10 – ½” Hunter Calibre: the first one has a much simplified balance wheel and the movements are usually 17 jewels and, the second one, also used this simplified balance wheel and is signed “Rolex 15 jewels Swiss made” on the winding wheel.
The earliest Perpetual models had three immediate factors: the engraving, the rotor and a small slot in the top plate of the frame in order to facilitate the adjustment of the regulator without removing the rotor and its accompanying plate. It was replaced by the “Swiss Made”, engraved around the center retaining screw.
The last original movement was replaced by one that reaches to the edge of the case and it has no longer a movement ring: the Chronometer. By 1944, it changed again adding the signature “oyster Perpetual” for the first time. Then, it changed again from being based on the 9 – ¾” Hunter to the 10 – ½” Hunter. This last version was launched as the calibre 720 and it continued till 1950 when it was changed for the calibre 1030. This last one had a flat rotor, two angled cuts ending in circles and a Rolex coronet engraved on the rotor with the legend “Rolex Perpetual”. The model 1030 wasn’t based on a Hunter movement and it was also the first to wind in both rotor directions. Even though the calibre 1030 was a very successful model for Rolex, because of technology developments, it was replaced in 1957 by the new calibre 1530.
The calibre 1530 featured a flatter rotor with five complete annular cuts and two open cuts. The movement was equipped with a free sprung balance produced by Stella for Rolex and it was timed by screws on the wheel rather than the traditional regulator.
Between 1957 and 1977 the 1500 series was introduced. The first one was the calibre 1535 with a progressive calendar mechanism. This model was followed by the 1555 calibre launched which was then followed by the 1565 GMT. In 1964, with the introduction of the faster beat train, meant the rename of the all the previous ones. The new Milgauss featured the calibre 1580. In 1977, the Datejust was introduced; calibre 3035, capable of improving the exactness of the watches. The calibre 3035 was the first one to be fitted with a “quick set” date wheel.
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