The Delrin Project: When did Omega switch? Howdy, I was contacted by larrymcduff one August morning with a couple of follow up questions and he asked a question that I can't really answer because the further I look into the issue the murkier it becomes. The question is "When did Omega switch to the Delrin part in the c.861..."... So I looked around my iPhoto archive and found this shot: of my c.866 Moonphase Omega (1986), which has a Delrin brake in it. So it seemed that the switch date could be pushed back to at least 1986 (if the parts in my c.866's movement is all original). So I checked my Mark II's (one I've owned since 1983)... Both have metal parts and the Serial Number would tend to indicate the vintage as prior to 1975. It occured to me that this would be a good Omega Forum participation project... So I posted an appeal to the TimeZone Omega Forum to "Scour your pictures of your moonwatches, Mark II's, Seamasters, and other c.861 Omega's between the years of 1968 and 1997, reply to this message in the form of the chart above (Discription, Case Reference, S/N: (xxxing out the last three digits), Brake Material:) and I'll compile a table of what is reported. Perhaps we can nail down when this happened on our own." Here is the table as it currently stands: Watch CaseRef. S/N Material Year by SN / known Owner Added Seamaster Cushion White Dial 145.016-68 "27,710,xxx " Metal 1968 - Known CM3 8/17/03 Black Dial Mark II 145.014 "28,xxx,xxx " Metal c.1970 SteveW62 8/15/03 Roulette Wheel Seamaster 145.019 "29,606,xxx " Metal c.1969 CM3 8/17/03 Speedmaster Pre-Moon Pro 145.022-69 "29,638,xxx " Metal 1969 - Known CM3 8/17/03 Anakin Skywalker Seamaster 145.023 "30,xxx,xxx " Metal c.1971 SteveW62 8/15/03 Black Dial Mark II 145.014 "30.387,xxx " Metal c.1970/1971 CM3 8/12/03 Seamaster White/Red/Black 145.020 "31,327,xxx " Metal c.1972/1973 CM3 8/17/03 Red/Orange Dial Mark II 145.014 "32,200,xxx " Metal c.1973/1974 CM3 8/12/03 Darth Vader Seamaster 145.023 "32,202,xxx " Metal c.1973/1974 CM3 8/17/03 Anakin Skywalker Seamaster 145.023 "32,202,xxx " Metal c.1973/1974 CM3 8/17/03 Seamaster "Hexagonal" Case 145.025 "32,206,xxx " Metal c.1973/1974 CM3 8/17/03 Black Dial Mark II 145.014 "32,xxx,xxx " Metal c.1973/1974 SteveW62 8/15/03 Speedmaster Pro 145.022 "39,xxx,xxx Delrin c.1976-1977 Adriano P. 1/17/07 Speedmaster Pro 145.022 Not Provided Delrin 1981 Reza 8/13/03 Tutonic TT/Black 145.004 to small to read Delrin c.1982-3 Eric So 8/16/03 Tutonic TT/TT 145.004 "44,120,xxx " Delrin c.1982-3 CM3 8/17/03 Tutonic TT/Black 145.004 "44,124,xxx " Delrin c.1982-3 CM3 8/17/03 Speedmaster Pro 145.022 "45,561,xxx " Delrin 1981 RogerZ 8/12/03 Tutonic SS/Gray Dial 145.004 "47,134,xxx " Delrin c.1982-3 CM3 8/17/03 Tutonic SS/Black Dial 145.004 "47,306,xxx " Delrin c.1982-3 CM3 8/17/03 Omega Moonphase (c.866) TI 345.0810 "48,228,xxx " Delrin 1986 - Known CM3 8/12/03 20th Anniversary Ed. SpMP ST145.022 "48,254,xxx " Delrin 1989 - Known CM3 8/17/03 Speedmaster Professional 145.022 "48,312,xxx " Delrin June 1994 - Known SteveW62 8/15/03 At this point we have a gap between 1974 and 1981. The c.861's produced before 1975 all appear to have a Metal Break, the ones after 1980 Delrin. So we really need people with 1975 through 1980 Omega Chronographs with the c.861 movement to take a gander at their movements and post the results. In the meantime when I first posted this, L. Estrada posted this reply (in bold italic type) with my response): Hi to all. I have been buried with work, and haven't visited much in the last weeks TZ, for my regret but every time I can I enter TZ. Today I saw a message posted by Chuck Maddox some four days ago about the date of introduction of the synthetic "brake" in the Speedmaster Professional; also he was asked by larrymcduff about the reliability of this part. Maybe I can give a little information about it since I once asked Mr. J. Diethelm about this part. He answered me a quite detailed mail and might be usefull, if not about an exact date (although he gives a significative date that might give some light to the problem). I transmit here what Mr. J. Diethelm wrote: " For your information, the " nylon " part , is not made of such but is a very special synthetic material, allowing to preserve the edges of the tooth of a very fine wheel, when returning the chronograph hand to the point " zero " , i.e. this part is having the function of a " brake " ! Several years ago, this part was made of steel, though showing little danger of wear-out but still, we wanted to improve to the best possible quality the performance of our " Moon watch " movement and this is why, the steel part was exchanged for a new " synthetic " material " ! Therefore, all movements of caliber 861 or the newer caliber 1861 ( rhodium plated ) are having this " brake " part in synthetic material, while the " de luxe " movement of caliber 1863 ( for the sapphire case back watches ) is having this "brake " again in steel ( since 1980 ) to preserve the " optical aspect " best regards John R. Diethelm. " I hope this helps, if I get to know more about it I will post again. Best regards L. Estrada Thanks LE... I haven't exactly been bombarded by responses, but I thank Steve Waddington, Roger Zimmerman, Reza and yourself of course for your insights... I will be doing the first draft of the table today, and check my Tutonics this afternoon (After an eBay auction closes). However, at this time, I can reveal, that I'm rapidly zeroing in on 1980 as the most likely date when the Delrin part was switched to (with the exception of the c. 861L, c.863 and c.1863 display back variant models. But, we'll know more as people report their findings. BTW... The first draft of the nifty S/N chart that Roman mentioned earlier this week is complete and can be viewed on my website. Thanks again Roger for permission to include it with Frank N. and my table. I haven't had the time to include it into the page with Frank and my chart, but maybe later today... Cheers! -- Chuck Larry's email that started all of this and my reply is reproduced below: I am very grateful to have you respond to my posts. Not a problem at all, happy to do it. I am a new moonwatch owner but have read about them and the space program in general for many years. I respect your opinions very much. Thank you for your kind thoughts! I was wondering if I could bounce two more questions off of you? Feel free... First, do you think that the moonwatch was ever Nasa tested with the nylon brake, and if not, would its presence affect its reliability? There is a big question out there pertaining to when exactly Omega started substituting the Delrin brake for the previous Steel ones. We had been happily plodding along thinking that the change happened in the same 1996/1997 time frame when Omega switched to the Rhodium plated c.186x movements from the Gilt plated c.86x movements for the moonwatch. But recently we've found Moonwatches dated earlier than that which have the brake... Early 1990's models, and maybe even late 1980's models (I'm not sure memory wise)... In fact I just pulled up a picture of my c.866 Moonphase Omega (1986) it has a Delrin brake too... So the question is when Omega made the switch.... Perhaps this would be a good TZOF project... I'll see if I can work up a post on the topic... If the switch happened prior to 1977 then the answer would likely be yes, NASA probably tested the Delrin models, if after 1978 then they didn't. I doubt that it would make much difference, if the temperatures that would cause any difference in the viability of that part (between Delrin and metal) were to occur, then that part failing would be the least of that astronaut's worries. So, the more the merrier! Let's drop the pants of those c.861's and gawk! =) -- Chuck Chuck Maddox (Article index @ http://chronomaddox.com/cm3articles.html)