robusa Posted February 3, 2010 Report Share Posted February 3, 2010 hi guys, the 7750 has issues on the rolex daytona. Does this mean it has issues on breitling chrono, navtimers and other watches with chronos? thanks guys! Quote Link to comment Share on other sites More sharing options...
ubiquitous Posted February 3, 2010 Report Share Posted February 3, 2010 If you have the 116520 daytona rep with the running seconds @ 6:00 7750, then this particular movement is problematic due to the modifications needed to shift the running seconds output to it's unintended location. The standard 7750 has running seconds at 9:00; these are far more reliable as the movement is not altered in any way and the stopwatch functions/subsidiaries are as intended. Quote Link to comment Share on other sites More sharing options...
TeeJay Posted February 3, 2010 Report Share Posted February 3, 2010 Would a standard a7750 from Cousins have seconds @9? I tried registering with them to check out the movements, but for some reason, trying to log in just crashes my browser Quote Link to comment Share on other sites More sharing options...
ubiquitous Posted February 3, 2010 Report Share Posted February 3, 2010 A standard Valjoux/ETA and Asian 7750 has: -Minute counter at 12:00 -Running seconds at 9:00 -Hour counter at 6:00 A tricompax Valjoux/ETA 7753 has: -Running seconds at 9:00 -Hour counter at 6:00 -Minute counter at 3:00 Most reps with the tricompax layout 775x watches are in fact modified 7750's with the minute counter output shifted to 3:00. Because the minute counter is not a constantly running gear like running seconds, the shift in output for this function is less critical. And some reps do in fact have true 7753's inside (they are quite pricey, however). Modified A7750 movements that shift running seconds output to 6:00, 12:00 or 3:00 may exhibit some problems over time; how soon or long that takes is really luck of the draw. For more information regarding these movements, have a look at some of the articles Zigmeister has done on the 7750's. Lots of good reading and disection which outlines where these movements go wrong. Quote Link to comment Share on other sites More sharing options...
TeeJay Posted February 3, 2010 Report Share Posted February 3, 2010 A standard Valjoux/ETA and Asian 7750 has: -Minute counter at 12:00 -Running seconds at 9:00 -Hour counter at 6:00 A tricompax Valjoux/ETA 7753 has: -Running seconds at 9:00 -Hour counter at 6:00 -Minute counter at 3:00 Most reps with the tricompax layout 775x watches are in fact modified 7750's with the minute counter output shifted to 3:00. Because the minute counter is not a constantly running gear like running seconds, the shift in output for this function is less critical. And some reps do in fact have true 7753's inside (they are quite pricey, however). Modified A7750 movements that shift running seconds output to 6:00, 12:00 or 3:00 may exhibit some problems over time; how soon or long that takes is really luck of the draw. For more information regarding these movements, have a look at some of the articles Zigmeister has done on the 7750's. Lots of good reading and disection which outlines where these movements go wrong. Thanks for the information, that's reassuring to know, as Project Daytona has the seconds @ 9 subdial, and I figured if I was going to build a wearable Daytona using that dial, I might as well have one with working chrono features, rather than day/date/24 hour, simply because it had the correct detailing on the sub-dials (I'd be quite happy with the d/d/24 movement, providing the subdials reflected those measurements ) Quote Link to comment Share on other sites More sharing options...
Bike Mike Posted February 3, 2010 Report Share Posted February 3, 2010 You can not swap the running Sec. @6 movement with a A7750/7753 tircompax. The subdials are closed to center then the tricompax. I tried once upon a time when first getting into the rep world. Quote Link to comment Share on other sites More sharing options...
TeeJay Posted February 3, 2010 Report Share Posted February 3, 2010 You can not swap the running Sec. @6 movement with a A7750/7753 tircompax. The subdials are closed to center then the tricompax. I tried once upon a time when first getting into the rep world. Thanks for the tip Might you have the measurements for the subdials? I only ask, as I'm not too sure what movement the dial is spaced for Quote Link to comment Share on other sites More sharing options...
ubiquitous Posted February 3, 2010 Report Share Posted February 3, 2010 That is correct regarding the sec at 6:00 7750 for the Daytona rep. Because this movement is replicating the gen 4130, the 9:00 and 3:00 subdials are shifted slightly above axis of center (i.e. they are positioned closer to 10:00 and 2:00); the gen movement has the subdials positioned in the same locations as well. The only reasonable swap for one of these movements is the same modified 7750 movement, which will also be problematic as-is without further modification. Quote Link to comment Share on other sites More sharing options...
Toadtorrent Posted February 3, 2010 Report Share Posted February 3, 2010 Thanks for the tip Might you have the measurements for the subdials? I only ask, as I'm not too sure what movement the dial is spaced for As well, I have not seen anyone "reputable" (i.e. Cousins, Ofrei, Somal, etc) selling A7750's in any modified form (bicompax, tricompax wide or narrow, etc) outside of our dealers here on the board who source them from the factories in China. Quote Link to comment Share on other sites More sharing options...
ubiquitous Posted February 3, 2010 Report Share Posted February 3, 2010 TeeJay- Do you have a pic of the watch/dial project you are working on? It should be fairly easy to tell by looking at it... Quote Link to comment Share on other sites More sharing options...
TeeJay Posted February 3, 2010 Report Share Posted February 3, 2010 TeeJay- Do you have a pic of the watch/dial project you are working on? It should be fairly easy to tell by looking at it... This is the best pic I have of it... The 3 and 9 holes have been broached, but I'd still like to try and make a project out of it Quote Link to comment Share on other sites More sharing options...
ubiquitous Posted February 3, 2010 Report Share Posted February 3, 2010 (edited) Dial looks like it's for a Seagull. I think I gave one to Toad that was just like it. Dunno that an A7750 mod-tricompax would fit it properly... The 7750 has large hour/minute pinions- That dial that you have has a small opening at the center and I don't think it will fit over the pinions regardless whether the subdials lined up with the pinions or not. Edited February 3, 2010 by ubiquitous Quote Link to comment Share on other sites More sharing options...
Bike Mike Posted February 3, 2010 Report Share Posted February 3, 2010 Thanks for the tip Might you have the measurements for the subdials? I only ask, as I'm not too sure what movement the dial is spaced for I can shot some pics of the 2 dials I have when I get home tonight. One is sec. @6 the other sec @9. will get you measurements as well. To Toads comment, there is a seller on eBay that comes from time to time that has the sec @6 movements. From your pic, it looks like a tricompax movement would work. Quote Link to comment Share on other sites More sharing options...
TeeJay Posted February 3, 2010 Report Share Posted February 3, 2010 I can shot some pics of the 2 dials I have when I get home tonight. One is sec. @6 the other sec @9. will get you measurements as well. To Toads comment, there is a seller on eBay that comes from time to time that has the sec @6 movements. From your pic, it looks like a tricompax movement would work. That'd be awesome, as I can then compare dimensions with mine I know the dial's less than pristine, but it's really taken my fancy (especially after I lumed the markers ) so I'd really like to try and use it in the project Since the above pic was taken, I re-enameled the bezel scale, and overall, I think it's looking pretty sharp on its new strap Quote Link to comment Share on other sites More sharing options...
TeeJay Posted February 3, 2010 Report Share Posted February 3, 2010 Dial looks like it's for a Seagull. I think I gave one to Toad that was just like it. Dunno that an A7750 mod-tricompax would fit it properly... The 7750 has large hour/minute pinions- That dial that you have has a small opening at the center and I don't think it will fit over the pinions regardless whether the subdials lined up with the pinions or not. The center hole shouldn't be a problem, I've enlarged the center holes on Sub dials to cram the dial over GMT movements before (although I didn't broach the subdials) Thanks for the feedback though Quote Link to comment Share on other sites More sharing options...
ubiquitous Posted February 3, 2010 Report Share Posted February 3, 2010 A 7750 has the following measurements for the pinions: Hour 2.00mm Minute 1.20mm So, the center hole of the dial needs to be a slight bit larger than 2mm. If you are able to broach the center hole, it may work. Quote Link to comment Share on other sites More sharing options...
TeeJay Posted February 3, 2010 Report Share Posted February 3, 2010 A 7750 has the following measurements for the pinions: Hour 2.00mm Minute 1.20mm So, the center hole of the dial needs to be a slight bit larger than 2mm. If you are able to broach the center hole, it may work. The center hole looks to be bang on 2mm... A touch of a file should take care of that I'm still having trouble accessing Cousins, but would I be right in thinking they'd sell the correct handsets for the movements as well? Quote Link to comment Share on other sites More sharing options...
ubiquitous Posted February 3, 2010 Report Share Posted February 3, 2010 What movement did you originally have in this case? The only other issue that I'd worry about is whether the stem will line up center in the case tube. Quote Link to comment Share on other sites More sharing options...
TeeJay Posted February 3, 2010 Report Share Posted February 3, 2010 What movement did you originally have in this case? The only other issue that I'd worry about is whether the stem will line up center in the case tube. I'm not sure, as the case and dial were a gift, and it came without a movement, but I can always ask Quote Link to comment Share on other sites More sharing options...
Toadtorrent Posted February 3, 2010 Report Share Posted February 3, 2010 Dial looks like it's for a Seagull. I think I gave one to Toad that was just like it. This is the Ubi-tona dial mounted on the Seagull ST19, sans hands: There are more pics but no dimensions in my guide on freezing the 6-o-clock subdial if you need them. Quote Link to comment Share on other sites More sharing options...
TeeJay Posted February 3, 2010 Report Share Posted February 3, 2010 This is the Ubi-tona dial mounted on the Seagull ST19, sans hands: There are more pics but no dimensions in my guide on freezing the 6-o-clock subdial if you need them. That definitely looks like the dial, might the ST19 be a safer bet for the movement (to fit the dial) than an a7750? Quote Link to comment Share on other sites More sharing options...
ubiquitous Posted February 3, 2010 Report Share Posted February 3, 2010 I would suggest the Seagull in lieu of the 7750. Likely to be less issues with getting everything to work/align properly. Quote Link to comment Share on other sites More sharing options...
TeeJay Posted February 3, 2010 Report Share Posted February 3, 2010 I would suggest the Seagull in lieu of the 7750. Likely to be less issues with getting everything to work/align properly. Thanks for the advice Once I get proper access to Cousins, I'll see what I can find Quote Link to comment Share on other sites More sharing options...
Toadtorrent Posted February 3, 2010 Report Share Posted February 3, 2010 I don't have a tricompax modded 7750 in any form (wide or narrow subdial spacing) to test the dial on...or I would try it out for you. I have Sixx's Ayrton Senna HBB ...but it's not mine...so don't feel comfortable taking it apart. Quote Link to comment Share on other sites More sharing options...
TeeJay Posted February 4, 2010 Report Share Posted February 4, 2010 I don't have a tricompax modded 7750 in any form (wide or narrow subdial spacing) to test the dial on...or I would try it out for you. I have Sixx's Ayrton Senna HBB ...but it's not mine...so don't feel comfortable taking it apart. No worries If I can get the dimensions for the pinion, I can compare them to the dial, and based on that, try and order a movement If it doesn't fit for me, I'm sure someone else would be able to make use of it Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.