RWG Technical

I have the first generation chief AR on my 007 Omega, been a daily wearer for 2 or so years, no signs of any wear or scratches on the crystal. I think it will last for a long time. RG

Is it harder to service a Asian 7750 vs an ETA one? The parts fit and process is all identical, where it gets "harder" is correcting the defects that exist on all the Asian 7750's...that takes time and skill beyond being able to take it apart and put it back together...there are a number of parts that are not to the required specifications and need to be adjusted, modified, fixed, etc to get the movement to work correctly. As the other posters noted, replacement is not a simple task, simply because you have no idea until you actually service a movement as to it's condition or if all the parts are adjusted to specs... Even buying a genuine ETA is no guarantee of serviceability, until it's been serviced. It's really difficult to get reliable and accurate timekeeping without having to invest in servicing at some point along the way. Or you can run it into the ground until it stops, and throw it out, some get years out of their watches this way...to each their own I guess... RG

Genuine or Asian, it makes no difference, the same principles apply. Toad's comments are right on... RG

All the best. RG

Looks great, well done. RG

Time is the factor. The oils will interact with the air and dry out and turn acidic, no matter if the watch is running or sitting still. Obviously if you never wind the watch it will never suffer any damage, but the key has always been to service the watch every 5 years or so to replace and remove the old lubricants. The oils also stay in their respective locations due to capillary action, unlike a car engine, the oils don't settle or need to be moved around by having the watch run for proper lubrication to take place. RG

Because Boob Frei is a jerk...that would be my guess. RG

This is what the container says it is "AF Lume compound", it is NOT Super Luminova or even close in terms of glow quality or the ease of application. There is only one Super Luminova, it's expensive as you discovered and only sold by RC Tritec. Don't even bother with any of the other so called offerings you see, they don't compare to the real thing... If you simply wanted something to practice with, nothing wrong with this kit, it's close enough that you get the "feel" for applying lume. RG

They look great, wonderful photo's as well. Thanks. RG

I would replace the mainspring and normally do as part of a service. Because the ETA 7750 runs at 28.8K, not at 21.6k, the mainspring is not compatible. The only mainsprings I can buy are ETA ones designed and made for the 28.8K models. The faster beat mainspring would have a higher denison strength than the slower beat one. Having said that, I have not tried the ETA spring in the slower beat movement to test it out, but it's a known that faster beats need more powerful mainsprings. Once clean and oiled, the rate over 24 hours static (not winding the movement) is within a few seconds, so it doesn't seem to be affecting the movement keeping the old spring in place. RG

The pushers and the stem are indeed sealed with o'rings. I will be taking them apart and replacing all the o'rings and applying new silicone. I think some of the dirt entered through the stem or pushers, and some of the dirt was from the gears wearing and seating into each other. The one picture where the great and 3rd wheels meet leads me to believe that the wheel to pinion rotation was responsible for the particles. Every watch "breathes" so to speak, when worn the case heats up and with it the air inside...warm, expanded it tries and does escape - if only slightly - past the seals. When taken off, the reverse happens, as it cools it sucks in ever so slightly some air and particles from the outside... Thanks for the feedback, the "book" is a ways down the road, when I find the time RG

Servicing and teardown of a 4 year old Asian 7750 21.6K model. A long time ago, in a land far away called RWG (the original RWG)

Looking good...great work knowing the amount of effort needed on this type of project. RG

Believe me, that was purely a fluke...not intentional at all... RG

Not interchangeable, the 7753 DW has a larger diameter than the 7750...you need a new 7753 dial to match the DW placement. RG

Had a look at the video, it's interesting and amusing but far from reality. No watchmaker would use #5 tweezers to assemble any movement, it would be equivalent to someone putting a 3/4" socket on a 1/4" ratchet. Using tweezers to "stabilize" the screwdriver is a no-no, there is no need to do it, and it's just not practical. As for the actual assembly, although it looks as if he assembled the parts, a real 7750 in the real world can't be assembled in the way shown. For example, the cannon gear is installed in the video by simply dropping it on the great wheel, in real life you have to press the cannon gear in place with a jewel press...the tilting pinion is dropped in place while the movement is running, and the lever is then installed on the tilting pinion, impossible to do in real life...and there is more... I would suggest that anyone viewing it take it for what it is, a show and tell on how a 7750 goes together, but if your expecting to use this as a guide in assembling a 7750 in real life, your going to be in for a rude awakening when it doesn't go together as shown... Thanks for posting it, it provided a nice touch to eating my lunch. RG

It looks great, well done. RG

I am not sure what models have blue lume and which ones have regular C1...I just lume them the colour the customer asks for. I think the blue lume is a nice change from the green glow we have all gotten used to seeing. Glad you like the results. RG

Factory specifications are +- 20 or more seconds per day accuracy, your above the acceptable rate...I would leave it alone. RG

Great how to, I did not know the older crowns were screwed in place...too bad they changed the design and you can't do the same with newer crowns. Wonderful way to salvage a really nice hard to find crown, well done and thanks for detailing it out, great pictures as well. RG

Beautiful, and in excellent condition. Wear it well. RG

You get into watch repair by contacting member Offshore and buying his CD set which includes the Time Zone course, do parts 1 and 2, buy quality tools, and your on your way to fame and fortune. RG

Great read, thanks for this. RG

The failure rate is so small...that it's a shock when one does come back due to problems... I don't know the 5 year rate, but I hear of so few that have caused problems after servicing that it seems to be a non-issue. In fact, the one that does stand out lately, was a genuine ETA 7750 from the batch that was sold here on RWG a while back. It has been back no less than 3 times for various failures and problems...surplus used vs new and unserviced...not sure which I would rather have. RG

I agree Francisco, and I have been saying the same about the standard A7750 for many years, unserviced = unknown. Until and unless you service the movement, you have no way of knowing if it will keep working. As for the design layout, I have been asking for 4 years now why they have to move the seconds accross the hour and minute tube and have that stupid gear with no jewels instead of bypassing and going around it...I don't have an answer. On the wear of gear "E", I have not seen any noticeable wear on this gear on any watches I have serviced. If your going to have something wear out there has to be friction, I believe the friction on this gear is very small, the gear is not heavy, there isn't a load that it's trying to move, so I don't think you will see much if any wear. I have noticed a lot of differences in the finish of the gears, so maybe this different finish looks like wear... I still read and hear people say that the "old" 21.6K A7750 is junk...I have a PAM 188 with this movement inside, it was serviced 4 years ago, it's been sitting and running NON-STOP for 4 years on my winder, and it keeps on working perfect... There is no quality control, I see A7750's (all types) that are completely dry, others that are covered in oil everywhere, others that are dirty...there is no standard, except when the watch is finally serviced correctly. If it wasn't like this, we would have nothing to talk about RG