freddy333 Posted November 5, 2007 Report Share Posted November 5, 2007 Has anyone removed either the rotor or, better yet, the entire auto-winding mechanism from an Asian 7750? I am trying to reduce the thickness of the movement so I can fit it into a shallower case. The rotor has a single screw that appears to lock it onto the rest of the auto-winding mechanism, but even after removing the screw I was unable to separate the rotor from the mechanism. So I started to remove the 3 screws that lock the self-winding mechanism onto the pillar plate, but I stopped after removing the 2nd screw because I noticed that the plate of the mechanism contains 2 jewels that appear to be acting as cap jewels for some of the chrono gears. It looked like removal of the self-winding mechanism might leave these chrono gears floating without cap jewels. Quote Link to comment Share on other sites More sharing options...
alligoat Posted November 5, 2007 Report Share Posted November 5, 2007 FWIW, I thought I read that a 7765 was a 7750 w/o the rotor. Quote Link to comment Share on other sites More sharing options...
RWG Technical Posted November 5, 2007 Report Share Posted November 5, 2007 The only gain you will have if you have a chrono 7750, is the thickness of the rotor itself. The bridge with the 3 screws, holds many parts for the chrono, and I would not remove it, as it's the most difficult part to get installed on a 7750. Stuck rotors are common, once the screw is out, just use a grey screwdriver to gently pry the rotor off the movement. RG Quote Link to comment Share on other sites More sharing options...
freddy333 Posted November 5, 2007 Author Report Share Posted November 5, 2007 Thanks Ziggy. I kind of thought that was the case, but I wanted to get a second opinion before I applied any force to the rotor. Quote Link to comment Share on other sites More sharing options...
RWG Technical Posted November 6, 2007 Report Share Posted November 6, 2007 Ok, good luck. RG Quote Link to comment Share on other sites More sharing options...
gplracer Posted March 10, 2009 Report Share Posted March 10, 2009 Rob or Freddy, Can I have some winding info? What is the proper way to wind a 7750 once the rotor is off? How much winding and how often (reserve). Also didn't you guys say there are some other parts that need to come out to keep the movement reliable if it is going to be wound? Thanks!!! Quote Link to comment Share on other sites More sharing options...
gplracer Posted March 12, 2009 Report Share Posted March 12, 2009 Rob or Freddy, Can I have some winding info? What is the proper way to wind a 7750 once the rotor is off? How much winding and how often (reserve). Also didn't you guys say there are some other parts that need to come out to keep the movement reliable if it is going to be wound? Thanks!!! Anyone know? Quote Link to comment Share on other sites More sharing options...
freddy333 Posted March 12, 2009 Author Report Share Posted March 12, 2009 The ETA 7750 has a 46 hour power reserve, but I do not know if the Asian version comes fitted with the same type of mainspring the ETA uses. However, based entirely on anecdotal evidence, I would guess the springs (& power reserve) are effectively the same. You have 2 options when converting the A7750 into a faux manual wind Remove only the rotor, which disables the automatic winding functions, but leaves the auto-wind wheels in place. This is easier, but the downside is that since you must now manually wind the movement at least every other day (if the watch is to be used as a daily wearer), you will eventually damage the auto-wind components (see Ziggy's A7750 articles for details of the possible problems that may result). Remove the rotor & the 4 wheels in the auto-wind module & then replace the empty auto-wind bridge (or leave it off altogether - 6 of 1, half a dozen of the other). This is a bit more work, but since you are removing all of the components that might be damaged by daily winding, you can then manually wind the watch without worry. (A 3rd alternative might be to remove the rotor & the 2nd intermediate wheel, which essentially sits in between the auto-wind module & the ratchet wheel (which winds the mainspring). This would disable the auto-wind function (since its connection to the mainspring barrel (the missing 2nd intermediate wheel) is no longer there) without having to remove all of the components. Still, considering that you have to remove the auto-wind module anyway, you might as well go all the way.) I do not have a 7750 schematic handy, but the components are similar to the 2846. Either remove all of the wheels in this picture & reinstall the empty bridge assembly or just remove the entire auto-wind assembly (& leave it off) The 7750 is modular in its construction. That is, it was designed to accept a set of sub-assemblies (like the auto-wind module). So the movement will run just fine without the auto-wind module. Here is a picture of 1 of mine with some of the auto-wind parts removed. I chose to leave the empty auto-wind bridges in place because they add a small bit of heft to the watch, which is a bit too light compared to my Valjoux-powered frankens Quote Link to comment Share on other sites More sharing options...
kbh Posted March 12, 2009 Report Share Posted March 12, 2009 (edited) I hope this will get answered since i just bought one. I understand that you take more than just the rotor off to make it wind like a manual watch. Maybe a couple of the auto winding gears? Edit: Thank you Freddy. We were both typing at the same time, I believe. Edited March 12, 2009 by kbh Quote Link to comment Share on other sites More sharing options...
gplracer Posted March 12, 2009 Report Share Posted March 12, 2009 Thanks Freddy. I really appreciate your time with this detailed post. Is this something that most any decent watchmaker can do? Quote Link to comment Share on other sites More sharing options...
freddy333 Posted March 12, 2009 Author Report Share Posted March 12, 2009 Yes. Quote Link to comment Share on other sites More sharing options...
Logan Posted March 12, 2009 Report Share Posted March 12, 2009 Just a thought.. will the manual wind parts in the 7750 be tough enough for daily use? I was under the impression that regular manual winding was not a great thing on 7750's.. Quote Link to comment Share on other sites More sharing options...
dieselpower Posted March 12, 2009 Report Share Posted March 12, 2009 I sent my Asian 7750 powered 6263 Daytona to Michael Allen for this work to be done. The rotor was already removed but he took out the auto wind mechanism to give the watch a more authentic feel during manual winding. When I received the watch it did not function properly and he has taken it back without question to sort it out. It remains to be seen weather the operation is successful. I'll keep you all posted. Quote Link to comment Share on other sites More sharing options...
freddy333 Posted March 12, 2009 Author Report Share Posted March 12, 2009 Diesel - I am sorry to hear about the problems. Hopefully, they will all get sorted out in short order. Quote Link to comment Share on other sites More sharing options...
gplracer Posted March 12, 2009 Report Share Posted March 12, 2009 What about winding? How much does one wind a watch of this type? I mean when you wind it how do you know what is enough and what is too much? Quote Link to comment Share on other sites More sharing options...
freddy333 Posted March 12, 2009 Author Report Share Posted March 12, 2009 The mainspring barrel in auto-wind watches is purposely designed to 'slip' the spring when it reaches full-wind, so, in essence, with this mod, you have the best of both worlds - a functionally manual-wind movement that cannot be overwound. As to the number of winds, I will defer to Rolex, who says it better than I can (& yes, this goes for most watches, including the faux-manual-wind 7750) Quote Link to comment Share on other sites More sharing options...
dieselpower Posted March 25, 2009 Report Share Posted March 25, 2009 I have still not got my watch back from Michael Allen but I did notice that when I wound it manually it only took about 17 winds and then it was fully wound ie the crown would not turn any further. I have no idea why this should be especially as freddy333 points out that the movement 'slips' the spring when fully wound. Quote Link to comment Share on other sites More sharing options...
freddy333 Posted March 25, 2009 Author Report Share Posted March 25, 2009 17 winds to fully-wind the spring sounds too low for an A7750. Did someone replace your mainspring with a shorter 1? And if the stem stops at that point, I fear there may be a problem. Quote Link to comment Share on other sites More sharing options...
dieselpower Posted March 25, 2009 Report Share Posted March 25, 2009 I don't know if the spring was changed. As far as I'm aware the movement is as it was originally supplied in the EE Daytona. I've had no info from Michael Allen as yet so will just have to sit it out and wait. Quote Link to comment Share on other sites More sharing options...
freddy333 Posted July 27, 2016 Author Report Share Posted July 27, 2016 Another old tech thread that might be of interest to newer members. Bumped. Quote Link to comment Share on other sites More sharing options...
ceejay Posted July 27, 2016 Report Share Posted July 27, 2016 Incase anyone is interested, if you want to do the manual wind conversion and make it look neat. You can install the manual wind (7765) bridge. This bridge will replace the auto wind bridge with a nice flat bridge. Cousins part no: Chronograph Wheel Bridge ( 8501 ), Valjoux 7765Product Code: VAL77658501 Picture... Quote Link to comment Share on other sites More sharing options...
freddy333 Posted July 27, 2016 Author Report Share Posted July 27, 2016 Nice. Quote Link to comment Share on other sites More sharing options...
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