RWG Technical

ETA cannon pins don't always fit on the A7750's for some reason, some do, many don't... The cannon pinion is the gear that separates the running part of the movement from the display part. Since the escape wheel effectively locks the movement as the balance swings, and lets out only one tooth each tic or toc, there would be no way to set the time, as those gears would be locked as well. The cannon pin/gear on any watch is the clutch between the going train and the display train, it allows the gears on top to move while the gears below keep running. When you move the crown to set the time, all the gears on the top of the movement turn, as does 1/2 of the cannon gear. You could only move the gears below if the pallet fork was removed. RG

If you want to it yourself, contact member Offshore and buy his CD with the Time Zone watchmaking school course. The 7750 is a very complex and difficult movement to service, as your first attempt for servicing you will ruin the movement. You have to start with the basics, and the TZ course is the way to go. Tooling alone will run into the $1000's of dollars, and you need many many hours of practice to have the skills for watchmaking. RG

Francisco is right. The cannon pin gear has no friction, no friction means no movement of the hour or minute hands. Common problem on the A7750, one of the many I fix when I do the servicing. RG

I will be spending some time over the next day or so, moving a variety of my posts from various area's of the forum, and consolidating them into my subforum. Things get lost when they are scattered around, so I would like everything in one area. So if when you click on "View New Posts" and you see what appears to be a new "old" post, you'll know why. Thanks for your understanding. RG

That is a wonderful reference, I have a printed copy in my files. Helps me a lot when I do my lume work. Thanks a lot for bringing it up again, always nice to look at the great pictures. RG

Although I did play hockey as a kid, I am not a fan today due to the amount of violence, "I went to the fights, and a hockey game broke out..." Just finished watching the Junior gold medal match, and nice to see that we won GOLD for the 5th year in row. One of the players is the son of my old school chums, so that is really nice. Great game, and great sport when it's a sport and not a goon match. Tonight's game could teach a lot to what they call the "Professional NHL league". Well done Canada. RG

They all look great, and wonderful pictures as well. RG

I agree. The majority of my tools are Horotec, much better price range than Bergeron (anyone who charges $300 or so for a catalogue of their products doesn't rate high in my book) and the quality is excellent. I have the set of screwdrivers from Horotec, the bracelet pin tool, the complete set of crystal press and dies, the bezel removal tool, and probably a bunch of smaller items I can't remember at the moment. Tooling for watch work is not cheap, but given the small sizes, and the tolerances we are dealing with, and the consequence of error, quality is one are that you can't skip...that and training and education and practice, without any of these, your doomed to failure when it comes to watch work. Good reminder. RG

Looks great, well done. RG

Incablock seems wrong to me...but the biggest problem I see is that it's a free sprung balance, yet the cock has "F...S" markings for a regulator arm. There is no arm, so what is incorrect, the balance, the cock, the shock setting, or all three. Don't think it's a mistake that the caliber markings are cut off in the picture. Good eye. RG

Incablock seems wrong to me...but the biggest problem I see is that it's a free sprung balance, yet the cock has "F...S" markings for a regulator arm. There is no arm, so what is incorrect, the balance, the cock, the shock setting, or all three. Don't think it's a mistake that the caliber markings are cut off in the picture. Good eye. RG

Place a piece of masking tape on the outside of the crystal, then press it out from inside as per normal. The tape will help keep the shards from flying everywere... RG

From what I see in the pictures he has posted, they look like excellent movements. As for second choice movements, I don't think a factory like this one is producing anything but one type. ETA does extra finishing and polishing etc to make the movements of different grades, I can't see these going through that many extra steps, why bother. So I think that all of these movements, like all the A7750's for example, are of the same quality and grade, good. As a comparison the Stellita copy of the 2824 is not that great, the few I have had in the shop had problems, and the Stellita is not interchangeable with ETA, so spares are not available. So Swiss made does not always mean quality... RG

Just finished various upgrades on this one. As much as I like to take credit for my workmanship, nothing to take credit for on this one as the parts are all gen: dial, hands, crown and the bezel insert. So I was only a parts changer, nothing more... Movement was serviced, and just in time. You know it's not going to be in good condition when the watch is not running, but there is still 50% of winding left in the mainspring barrel. Luckily there was no damage or worn out parts, just some old gummed up oil to be cleaned off and replenished. With all of these models, the bezel assembly can't be replaced with a genuine one as they are totally different sizes. The genuine bezel is about 5mm larger in inner diameter than the rep one, and will not attach to the case. To install the genuine bezel insert on the rep bezel assembly, requires a lot of machining of the back side of the bezel insert so it will fit flush with the rep bezel. It's interesting to note that the colour of the dial lume is slightly lighter than the hands lume. This is good to know, because I have installed a few gen dials but re-lumed the hands and ended up with the same effect. As with any Chieftang AR, this stuff is scary and is probably used as a steath technology somewhere... Overall view, under my powereful watchmaking lamp...not a hint of reflection anywhere...AR RULES Difference between dial and hands lume colour, it's slight but more pronounced in person with the hands being more yellow/green than the dial. Closeup of the gen crown and tube. Lume shot Thanks for looking. RG

If it was mine, I would do one of two things: 1. Try and get it fixed locally or by a trusted watchsmith 2. List the problems with the watch, and sell it at an appropriate price. I never send anything back to China, too risky in my view, that you have had it sent back and forth 5 times now (twice each time including original purchase), I would not risk loosing everything. RG

@ rangers Well said, you pointed out my biggest complaint over the years - unskilled Modders who haven't a clue as to what they are doing. I have seen my share of previously worked on watches, and the larger percentage fit your description of the poor workmanship quality, and horrible lack of any watchsmithing skills. Simple things like not leaving finger prints, or blowing off the dust before you put the caseback on, which takes little skill to do, escape these hacks. My solution to this particular problem is that I don't accept any watch unless they are virgin ones...I especially don't take in watches when the explaination of the problem starts with "...my local watchmaker messed up XXXX....and I was wondering if you can fix it...". There are good watchsmiths out there, but as you correctly pointed out, are hard to find. With no slow down in the production of mechanical watches, I wonder how the manufacturer's are going to cope with the after the sale service. It's one thing to throw out a $300 rep and get a new one when it stops working, but another totally different thing when your into a few thousand dollars for a gen. RG

I think the only test for a genuine vs aftermarket crown is to pull the crown to the time setting position. Then you can see the two o'rings on the gen crown shaft, the aftermarket ones don't have any o'rings. RG

Well since there are 11 extra gears for the moving of the subdial hands around the dial face, and each gear needs 2 jewels, adding 4 jewels leaves us with 9 gears still running on metal on metal... Wonder which 2 gears get the new jewels...2 of the 5 in the running seconds?? I won't be holding my breath on this one, but you never know...they got the seconds at 3 right, finally a good design. RG

I do believe I will have a Cousteau in the shop for lume today...and it's going to be done in the new C1 blue lume. So you'll have your answer before you have to decide, I'll post some pics when it's done. RG

Well said, all of it, especially the gym stuff. I guess I am old school as it's been just over 4 years for me... RG

Too many pages for me to read it all in detail, but from what I did see and read, and very well done comparison with great pictures. I can't imagine any non-oiled movement to last 10-15 years, well maybe if by "last" they mean run for that length of time, because it will surely be worn out when it finally does stop. Great link, thanks so much for posting this. RG

To answer the genuine tritum question, the answer is simple...well sort of... if you have a lot of time on your hands. What you do is look for the "lot" sales of old watches for sale from various sources, you buy these up normally for pennies per pound, then you keep those that are lumed with Tritium, and in your spare time, you scrape and save up the old tritium from these watches, and eventually you have enough scrapings to do a set of hands... RG

Because of it's historical value, I would leave it as is...it looks great. RG

The answer is: Genuine dial, untouched with genuine aged Tritium. Rep hands and pearl, lumed with Genuine Tritium. Genuine crown. Rep CG with new pin and polished. Bezel polished. Lello DW. Upgraded crystal and cyclops, with AR removed. New cap fabricated on lathe, polished, and installed on the minute hand tube. RG

Not too late at all...if you read my last answer, there is still some unanswered questions... RG