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In search of the perfect movement, Autotractor first used in Home Time and Dualmatic!

March 7 2004 at 9:22 AM

Jaw  (Login TJN)

(Obviously, in my eagerness to share my enthusiasm about the Autotractor, I have rushed this posting before my Shanghai Trip early next week. It is basically an instantaneous outpouring of what I have learnt. As such, I hope fellow members can be more forgiving. Hopefully, I can update and re-organise this posting in the future to make the post more coherent and organized)

(The Autotractor MJLC Calibre 975, exploding view)

This year, Jaeger-LeCoultre will launch a very impressive super complicated wrist watch, in which the idea conception, Research & Development, movement design and the final working prototype took more than 2 years from the time of Eric Coudray and his development team.

Yet as this top-secret piece was going on, far more number of people in a team, led by R&D Director, Jean-Claude Meylan have been working for more than eight years since 1996 to produce the most optimal, reliable, durable, accurate, easy to maintain, service and regulate and a relatively maintenance free basic automatic movement.

(The partially assembled calibre 975)

This is the "Autotractor" that needs to be as heavy duty and reliable as a 'Tractor'. And has to be more efficient and reliable than the already reliable JLC range of movements.

The objective is clear, despite exceptional current effort to ensure reliability in Quality Control department, precision checking in every department and the toughest Master Control 1000 hour test, this new Calibre 970 family of movements have to be inherently better even before the Master Control 1000 hour test.

(The Micro Xcel Machine, automated tolerance check on each movement)

(A closer view of the Micro Xcel check)

(In MJLC, EVERY anchor movement in the escapement assembly is carefully checked with projected image to ensure reliability)

Mr. Meylan explains: ¡§Creating Complications like perpetual calendars, tourbillons, minute repeaters, and alarm functions, that¡¦s one thing. It¡¦s much more difficult to make a simple movement that is really good.¡¨ In order to pursuit for simplicity and perfection, the team has decided to kill several sacred cows and made significant changes, resulting in significant investments in new machines and tools.

(Jean-Claude Meylan, Director of R&D)

The Uni-drection winding Vs Bi-direction system have been going on for as long as I remember, is a bidirectional winding rotor more efficient than a unidirectional one? Seemingly, there is still no conclusive evidence proving the general superiority of one over the other.

(Functioning cal 975 parts during rotor winding)

(Functioning cal 975 parts during crown winding)

JLC traditionally favoured the bi-directional winding in which the winding efficiency is consistently proven to be better in a cyclo-test. The cyclo-test result is no different for the new ¡§Autotractor¡¨ calibre. Not satisfied, Mr. Meylan carried out extensive test on real wrists. The result is a surprising one as single-direction winding autotractors consistently produces much more energy when worn on wrists in real life conditions and habits. Jean-Claude Meylan decides it is time to make the change for autotractor and throw out conventional wisdom in this case. Although he understands that his real test results are conclusively in favour of the new uni-directional winding rotor, he doesn¡¦t expect the continuous debates between specialists to end here.

(Ceramic ¡§Zirconium Oxide¡¨ Ball bearing mechanism for the oscillating weight and the coupling lever ensures reliabily of the winding mechanism without lubricant)

In terms of maintenance issues and long term reliability, the development team believes that the weakest link of any automatic watch is the rotor winding system. A place where most wear and tear takes place (this explains why I personally don¡¦t like to put my watches on winder). To ensure minimum friction and eliminate the need of lubricant on the ball bearings, The autotractor will use only Zirconium Oxide (Ceramic) tiny balls, a technology jointly developed by a supplier and JLC . In internal accelerated age testing, the ball bearings show no visible wear under high magnification even after 1.5 million continuous rotations. While JLC will be the first to use the Zirconium Oxide balls, the technology is not exclusive to the manufacturer.

(Clean ball separator after 1.5M rotations)

(Bearing without corrosion after 1.5M rotations)

The most decisive changes are implemented in the escapement mechanism.

(The bigger balance wheel being fabricated in the factory)

Firstly the specially designed balance wheel is now larger for better precision and finally, free sprung (right on!). Balance wheel moment of inertia has also been increased more than 350% to 14mg/cm2 as compared to the older movement (e.g. 3.8mg for calibre 899). The development team chose the highest optimal moment of inertia value of 14mg/cm2 as movement stability improved steadily in correlation with inertia until this optimal value.

(Manel Guerin, my teacher and lifesaver)

In addition, 4 strategically placed screws in the balance wheel (to vary inertia) allowed a wide range of easy regulations. New and specially customised regulating machines will be provided to MAJOR Service Centres to ensure quick and accurate regulations. After being briefed by Manel Guerin, I successfully regulate a -47s/day movement to both the beat error and daily gain rate to ZERO in less than 2 minutes (I am technically untrained).

(The overall view of the regulating machine)

((1) Push the black lever to stop the balance wheel, (2)Move this to turn the balance wheel to the right position while watching screen 4, (3) screw the balance wheel screw in to gain time and unscrew to lose time, divide the deviation by half, adjust diametrically opposing screw half the error each, (4) watch the lcd screen to have an idea of what I am doing (5) check beat error and deviation as the screw is turned, the reading reacted in real time ¡V VOILA!)

(This is yours truly, regulated the movement to zero s/day in less than 2 minutes)

(Each screw is carefully screwed into the balance wheel at the factory)

Specially made tools (with clearly label and marked angles) will also be provided to all service technicians for quick adjustments when the machine is not available. For someone who has seen a master watchmaker spending more than 2-1/2 hour regulating another watch recently, this is pure MAGIC! (Bravo!)

(This tool make manual regulation easy, just screw in or out according to the marking depending the amount of regulation needed)


(Conventional assembly)

(The new Calibre 975, (a) A New balance wheel featuring large and variable inertial, (b) Balance Spring now welded to the collet and to the Balance spring stud (c) Balance spring stud holder locked by screw (d) Balance bridge with 2 supports for greater stability (e) 2 catches marked "A" now holding the balance spring in position even when subjected to great shock)

To make the movement more robust the vane, which was traditionally fixed on just one side, has been transformed into a balance bridge screwed in two places to the deck.

(Each mainspring carefully place on top for welding)

(The Laser Cheval ¡V horse machine for welding the mainspring to stud and collet, despite using this expensive machine, each mainspring must be carefully placed on top for the welding process)

In addition to Incabloc, Both ends of the spiral are welded by laser to the stud and collet plus additional 2 ¡§catches¡¨ which will prevent alteration to the setting as a result of a violent impact on the watch. Repeated shock tests demonstrated seemingly unable to damage or stop the watch.

(The Shock Test done repeatedly. It didn¡¦t damage the watch, but I can¡¦t bear to watch this)

(The point of impact from the test, obviously dented with the watch intact)


+++¡§SPYR¡¨ gear train has a slightly rounder teeth shape as compared to industry standard to optimize torque transmission and reduce energy losses, this gear train technology jointly developed by 12 brands is not exactly new but perhaps first implemented only in JLC MecaQuartz. The ¡§SPYR¡¨ gear trains were not used in other models perhaps due to the higher cost needed by the necessary tooling.

(The ¡¥SPYR¡¦ gear train versus industry standard)

+++The small second hand is placed directly on the seconds wheel. As Jean-Claude Meylan explains :¡¨We wanted to go about things in our own way and we are convinced that the future belongs to the small second.¡¨

+++The 2 timezones are designed from scratched and integrated in the movements. Of course, this does not imply all watches using this family of calibres must be a GMT watch (can be disabled or ignored)

(The fully integrated 2 timezones functions in Autotrack)

+++A new Maltese cross mechanism ensures that very little energy (near zero) is needed to change the date, an obvious improvement over traditional date change mechanism, instantaneous or otherwise. Furthermore, Date change can be adjusted backward and forward with ease and reliability.

(The Date change mechanism requires negligible energy)

+++A joint research and development between Jaeger-LeCoultre and Lange Uhren has successfully manufacture mainspring in house for some time now. The mainspring is physically produced in Lange premise in Glashutte for space and financial reason. (According to a friend, this is wholly Lange¡¦s work, I shall seek clarification on this point although I tend to believe it is a joint development at this juncture)

Obviously, none of the technology used here can be considered as revolutionary technical breakthrough individually. However, in combination, it is obvious that compared to other brands, JLC has shown that they are willing to put in a relentless effort and inject heavy financial investment to make even basic calibres much closer to mechanical perfection.

I take off my hats to all of you who are involved in the Autotractor Development process.

Jaeger-LeCoultre Calibre 975 (Master Home Time) or 972 (Master Compressor Dualmatic)
2 integrated time-zones
Date change in both directions
Automatic winding
28,800 vph
50 hours of power reserve
29 jewels
230 parts
Movement height 5.7mm (975) or 5.6mm (972)

(Master Home Time)

Master Home Time:

A new GMT watch uses the autotractor calibre 975. Looks more like the Master Eight Days and Master Antoine-LeCoultre than any other Master range of watches. My guess is that all future Master products will continue with this ¡§new¡¨ look.

Aesthetically designed by Janek, the watch is simple and understated. What I like is the overlapping 2 hour hands which can be used as a single time zone watch without attracting attention or when adjusted by the crown in position 2, the local time hour marker (in blued steel initially below the home time hour hand) will start to add or deduct hours from the home time hour marker. The date is synchronized with the local time hour marker which can be adjusted forward or backward.

(Master Home Time Designer, Janek Deleskiewicz)

The Day/Night indicator is always synchronized with the home time hour hand so that traveler knows if it is day or night at home.

Autotractor Calibre 975
Water resistant to 50M

(Sapphire Caseback view, Master Home Time)

Local hour hand can be move forward and backwards
Date function synchronized with local hour hands, can be adjusted forward or backward.
Home Time Hour hand
Day/night indiacator linked to home time hour hand
Minutes and small seconds hands.

1 crown for starting the watch and setting both local and home time, minutes, date, and day/night indicator.

(Master Home Time)

Silvered sunray-finished, applied numerals and hour markers either rhodium plated or in white gold 12 luminescent dots.

Minute and local hour, alpha, rhodium plated or golden brass, luminescent
Home Time, blued steel
Seconds hand in bass, blue lacquered

40mm diameter, cambered sapphire crystal, hardness No. 9
Sapphire base through which the movement can be viewed
Available in stainless steed or 18 carat pink gold

Matt brown alligator leather 21/18 with 18mm folding clasp in steel or 18 carat pink gold.

(Master Compressor Dualmatic)

In my opinion, this watch designed by Magali Metrailler looks great on both men and women even at 41.5mm diameter

(Magali Metrailler, Master Compressor Dualmatic designer)

Master Compressor Dualmatic:
Work the same way as Master Home Time except for the 24 hour indicator (instead of Day/Night indicator).

(Sharon Mei trying out the new Master Compressor Dualmatic, impressive!)

In this case the local hour hand hides beneath the openworked home time hour hand when not in used. The local time hour hand can be adjusted forward and backward upon a new destination.


Calibre 972
Water Resistant to 200M according to caseback marking (100M according to pre-SIHH press kits)
Internal rotating bezel
Compression Key system.

(Master Compressor Dualmatic)

Hours, minutes, small seconds at 7 o¡¦clock, date, 2 individually manipulatable hour markers, 24 hour indicator in a semicircular window synchronized with the home time hour hand,

Brilliant black or charcoal grey or slate grey with luminescent numerals and hour markers

Local hour hand in rhodium plated brass luminescent
Home hour hand in openworked white lacquered brass
Small seconds in white lacquered brass
Minute hand in rhodium plated brass luminescent

1 crown with compression key at 2 o¡¦clock to adjust the rotating bezel
1 crown with compression key at 4 o¡¦clock for initial setting and starting, and moving the local time hour marker forward and backward in one hour step (leap)

41.5mm diameter
Sapphire crystal, hardness No. 9
Case back features a solid gold 1000 hours control medallion
Available in stainless Steel, white gold or yellow gold.

Stainless Steel model with caramel coloured calfskin strap, double stitched with stainless steel folding buckle
18 carat pink gold with matt chocolate coloured alligator leather, double stitched with 18 carat pink gold folding buckle
18 carat white gold matt honey coloured alligator leather, double stitched with 18 carat white gold folding buckle.

18 carat pink gold or steel, patented, 5 dual-axis links
Polihed links for gold model, 3 brushed central links and 2 polished lateral links for the steel models.
Patented clasp, made up of 52 parts, with length change enabling fine adjustment over 2 x 4 mm

ps, I apologise in advance as I may be unable to reply email or answer question in the next few days, take care and enjoy!


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