Page 8 of Damasko Catalog by Damasko

the oil-free escapement for over 100 years the swiss anchor escapement has been the most precise and reliable escapement for wrist and pocket watches in order to work properly it needs to be oiled regularly on the palettes and on the teeth of the escape wheel and in addition to that watch manufacturers recommend to service a mechanical movement every 2-3 years by disassembling cleaning and lubricating it an insufficiently oiled or even dry escapement ultimately results in bad accuracy or even worse in worn out parts since 1998 damasko has experimented with different kinds of coatings which should lower the friction coefficient between anchor and escape wheel latest technological achievements showed that coatings made of various layers of amorphous carbon diamond like carbon dlc are probably the most advanced solutions to create a dry escapement the process to generate such a layer is called plasma activated chemical vapour deposition pacvd apart from its black colour the coating features the following characteristics · · · · · · extreme hardness of approximately 1800 ­ 3000 vickers excellent wear resistance high chemical resistance superior surface quality extremely low friction coefficient dlc ­ steel 0.07 without lubricant movements parts can be coated at a temperature that does not affect the structure of the metal 200 degrees this coating process was originally designed to increase the wear resistance of moving engine parts cutting tools and even medical implants in addition to the hardness and wear resistance of the layer the extremely low boundary friction coefficient makes this method of coating so interesting for us we started by coating the escape wheel of the ubiquitous but reliable eta 7750 with amorphous carbon as mentioned above the combination of the ultra-hard carbon layer and the polished synthetic rubies al203 of the anchor already lead to a very good boundary friction coefficient which allowed us to construct an escapement which works fine without any lubricant at a daily accuracy of approximately 2 seconds furthermore the escapement delivered an amplitude of 290-325 degrees which is already very good but we thought that the combination of dlc on dlc should deliver even better results we went one step further and designed an new one-piece anchor with a modified geometry and slightly different parameters after polishing tempering and again polishing this anchor was also dlc coated and fitted to the movement the result was absolutely amazing due to the extremely low friction coefficient of dlc on dlc the escapement delivered an amplitude of 300 ­ 347 degrees without any lubrication of course this was only a test run in order to make sure that this result will also be achieved during serial production it is necessary to establish an effective quality control after two years of extensive testing on different movements no signs of wear can be regarded and the escapements still deliver excellent amplitudes during our latest test run we replaced the synthetic rubies of the anchor by palettes made of silicon carbide and found out that this innovative material is another outstanding friction partner for the dlc coated escape wheel.

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