RWG Technical

Great post, well done. I can't imagine how much time this took to compile. RG

Normally these two statements don't go together. A 7750 is a very complex movement of which not many watchmakers can fix, a 7750 with seconds at 6 is even more complex, asking for a reasonable price for work on this type of movement is asking for the impossible. Like anything in life, you get what you pay for. Freezing the subdial is a short term solution, and may or may not work, the long term solution is to freeze the subdial and also service the movement. Tom is your only choice in the EU. RG

What kind of texture are we talking about? Paint can't cover up underlying texture, you have to eliminate the texture first and then clear coat it, and that is not always possible, especially around the numerals and lettering... RG

That movement is the Maytag of the watchmakers world...they never break down... Wear and enjoy, get it serviced in 5 years if it's a keeper... RG

Well that's a first...normally I can't even understand what I say sometimes, especially the tech stuff RG

Fitting the crown and tube on this case is no different than on any other model. Your going to need the correct drills, the correct tap, and the tube insertion tool. It may fit without any modifications to the case, but you will probably find the hole too small. So you will need to drill it for a M3 X 3.5mm tap, and then tap the hole (with the M3 X 3.5mm tap). Once it's drilled and tapped for the tube, you will also need to drill a larger hole on the outer edge so that the tube will sit flush with the case. Hard to explain in words, but once you insert the tube into the case you will know exactly what I mean, the tube doesn't sit flush, the tube has a larger tapered section that keeps it from sitting flush. You need to drill a chamfered hole to allow this section to sit inside the case. RG

I knew you would figure it out and fix it, congratulations excellent job! RG

Datewheels are not interchangeable between these movements. If the DG has an overlay on it, you can transplant this to the ETA, no reason to disassemble or remove the ETA wheel to do this. If there is no overlay on the DG, you can't glue the DW onto the ETA, it will end up too thick and jam up against the back of the dial. RG

Looks great. My only suggestion would be to broach the 12 hour hand slightly so it sits further down on the dial, there is a risk of the hour hand touching it. Congrats on such a nice piece. RG

Looking really nice. It's so disapointing when you see damaged screw heads on these old vintage movements, if someone has the skills to service the movement, you would think they would have the skills to use the correct screwdrivers. RG

Yes the Horotec bezel remover is expensive, but when you need one, it's irreplaceable. It's almost impossible to not get any scratches when your trying to pry a bezel off with the knife blades of a remover, as long as you carefully position the case in the tool and carefully tighten it down so the knife blades sit between the bezel and case I find that the scratches are minimal to non existant. You can put a bit of tape on the case, but I find that this will move the blades up slightly and not allow them to fit in the gap between the case and bezel, so I don't tape the case. I also polished my blades to a mirror finish to reduce the scratching. Tools, especially good ones, will always pay for themselves over the long run. RG

For a while I though I was reading a great article in "HR Watches" magazine...but then I realized that no watch magazine I have ever read had any articles even close to approaching the detail, comedy, and excellent research that this article presents. Amazing, simply amazing, I can't thank you enough for the time and effort you put into producing this, it's EXCELLENT. I have a book in publication and I wrote for a magazine for a few years, and I know how difficult it is to accomplish what you keep posting for the RWG members. This is what makes RWG the number 1 watch (not only replica) site on the internet, bar none... Thanks again, very much appreciated. RG

If Invicta can make a clone of the Rolex submariner design, and sell it on the open market, my guess would be that the case, CG etc is open to anyone who wants to use it. I think as long as the name is not there, it doesn't matter. But when you look at an Invicta, it sure looks like a rollie... RG

It looks like Rodico, I don't know why it's there, I guess it is to hold the movement place. I robbed the pic for the wheel show and tell... RG

The smoothness of the sweep is directly related to the speed of the balance wheel. ETA's are mostly 28,800 Beats per Hour, or 8 ticks per second. Most Asian movements are 21,600 BPH, or 6 ticks per second. Handwinds are 21,600 or 18,000 (2.5 per second). If it's running ok, and keeping good time, then the ticks are what they are, you can't smooth it out. If you can open the caseback you can identify the movement type and then you'll know for sure the speed. What was it advertized as having for a movement? RG

Looks great on that strap, wear it well. RG

No Highjack at all... On your Omega this is perfectly normal, as it is on many vintage center seconds models. Reason is simple, the first center seconds movements were done using existing designs (which did not incorporate center seconds) and the way they got the center seconds was by adding a new gear on top of the 2nd wheel, and a pinion gear through the third wheel. This is what is called the "indirect" center seconds design, and since the new gear is very large and drives a tiny pinion for the seconds, there is slack between the gears and this slack causes the jerky hand when it's going with gravity. The next generation designs moved the second gear to the center of the movement, thereby eliminating the extra driving and driven gears, and we have a smooth direct drive center seconds. PICTURE of indirect seconds drive, see the big gear on top of the bridges, this is the extra gear, see where it sits in the center of the movement, this is where the pinion is located that drives the seconds. Apologies to Deltahoe, it's his picture I took, but it fits the need here nicely...and he's selling a bunch of stuff, go buy something from him if you found this useful RG

Very nice, thanks for the link. I would say the final video was a result of the marketing folks and not the watchmakers... There are many out of sequence procedures, both during disassembly and assembly, and shots of a watchmaker oiling a part that doesn't require oil, as well as some errors the a watchmaker would never do... Some shots of the watchmaker assembling the movement with all the bits and pieces laid out in front of him is also marketing, no watchmaker would do this because it would expose the clean parts and pieces to contaiments and dust. Too bad they used the marketing approach and not the watchmaker one, it looses it's value in my view. I think you'll find that most quartz movements, are accurate to 15 seconds per year, but where is the fun in that RG

The stem has nothing to do with the smoothness of the sweep of the seconds hand. The two are not connected. Something else is wrong, if it's an ETA it will be smooth all the time, the movement works or it doesn't, meaning the actual movement isn't going to go from smooth to jerky. So as others have said it's down to the seconds hand, since it was ok when you brought it in for repair, take it back and let them fix it. The other thing to try is where is it jerky on the dial face, at the same place all the time, or does it vary. Also with the watch vertical (ie off your wrist and held up), monitor the hand, is it smooth on the way up, from 6-12 and jerky on the way down 12-6? or is it jerky randomly... ETA movements are not jerky, so something else is messed up. RG

Looks great, wear it well. RG

I don't think this model has a notch cut into the bezel to allow a case knife to fit and pry it off. I use my Horotec bezel remover to get them off, but without something similar you may have problems, I DON"T recommend razor blades or box cutter knives, far too risky to really hurt yourself. If you can't get the bezel off, you can still get the broken pieces out by breaking them up with a flat blade screwdriver and small taps from a hammer, no matter how you go about it, it's not easy or fun and not without risk...I hate doing these. RG

I suggest the 2801-2, the FM is not really like any movement in our reps, the 6497 is far too big, you start on it and you'll have much trouble going smaller to a 2801. Basic tool kit is fine for starters. RG

Normally if the plate with the gear on it is too loose, meaning that there is too much of a gap between the datechange plate and the cover that holds in in place, I replace the cover with a spare one to see if this fixes it. It will be more clear to you when you open it up and have a look. Sometimes the datechange gear can also be loose, you will be able to see this when you test it. Also, you can have the datewheel sitting too high and not engaging to the gear teeth correctly. The reason for this is the datechange cover plate is not pressing down far enough to hold the datewheel against the movement. The fix for this is to try and bend the cover edge over the datewheel teeth down so it holds it down. As soon as you take it apart and test it, the actual problem will be visible and then we can take steps to fix it... RG

The manual date change is done with a small gear attached to a plate that engages into the clutch gear. The date change gear assembly is on a pivot and pin and moves from side to side, into the datewheel teeth to change the date, and out of the way so the datewheel can change automatically. Once the dial and hands are removed, insert the stem, put it in the datechange setting position, turn the crown, and look for the small gear that is on the plate. You will see it move from side to side as you turn the crown CW and CCW. MAKE sure you remove the stem in the WINDING position only or you will have problems. There is a defect with many A7750's with this gear and plate, the problem is that it doesn't stay engaged into the clutch gear and wobbles around instead of being firm. You will see a small cover over the datechange gear, remove the one screw for the cover, and remove the cover, and have a look at the gear assembly for any problems. You can eliminate the keyless works as the problem by simply going to the time setting position, if you can set the time ok and it doesn't slip, the problem is with the actual datechange gear not the keyless works. Fixing it can be many things, it all depends on the actual problem, which is why you have to inspect and investigate and discover what is happening, and then figure out how to fix it. RG

No need to remove anything but the movement. Since you have done this, now the hard part begins... If I remember correctly, the crystal is attached to the bezel on this one, you need to remove the bezel from the case, it makes it easier to do the next step. If you can't remove the bezel, it may be a bit of a problem getting the rest of the crystal out. Once I have the bezel and broken crystal out, I put on heavy leather gloves, eye protection, and lay down a layer of paper towels to catch the glass shards. Remember that the remaining part of the crystal is under tension. I get a pair of wire cutters, and with the bezel facing me, I insert the cutters from below into the center of the bezel and carefully crush/break up the remaining crystal pieces. It is not easy to get the glass out and you have to keep working at in... Be careful not to damage the compression ring, since you need it for the new crystal. Not sure how clear this is, but I think it gives you a general idea of what how I do it. RG