RWG Technical

If you think there is no sense in paying to have your watch serviced, then dont' do it...no one is forcing you to do anything. Of course your expecting a Gen to run without doing anything to it, but were talking about fake watches, not genuine ones...this is the reality of these movements, you may not like it, but that's the way it is... Changing the oil is a good comparison, but your forgetting that "Servicing" a watch is identical to a complete overhaul and teardown of the car engine... I use it as an example, because most people can relate to it...unlike watchmaking where most people are not informed as to what is done. Servicing a watch requires you to take the watch fully apart, to each and every last screw and component, clean them, inspect them, assemble them, oil and adjust them... etc....this takes time, skills, expensive and specialized tooling... How much would it cost to do this on a car??? Probably a bit more than $40... Your not comparing apples to apples in your comparison. Many choose to simply wear the watch until it dies, and buy a new one...that's perfectly acceptable...if you choose this route as well, plse keep me in mind when your watches die, I would like to have the spares... RG

Your comparing the cost of the servicing to the cost of the product, that analagy does not work... If I sold you a Ferrari for $1000 and the dealer wanted $1000 to adjust the valves, you would think your getting ripped off by the dealer... If you paid $150,000 for the car, you would think $1000 was a good deal... Just cause the watch cost $50 more than the servicing cost, does not mean the servicing cost should be adjusted to reflect a certain percentage of the cost of the watch... The same effort is needed to service your $250 7750 chrono, as is needed to service a $4000 Omega with a ETA 7750... There is no guarantee that changing and keeping fresh oil in your car engine will mean it wont' throw a rod, or break a valve...so do you not change the oil regularly because of this?? The 7750 has been around for 30 years, mechanical watches for much longer, it's a known fact that a clean and oiled watch will keep running and have the best chance of lasting a lifetime... Other than dropping the watch (which has nothing to do with servicing) there is little in a movement to "break" during it's life...keepign it oiled is the best insurance against it failing. Your having a hard time because your comparing the cost you paid to the cost to get it serviced...the two are mutually exclusive... See my Ferrari example above... I have no idea when your watch, or for that matter anyone's watch will die, if ever... It's luck of the draw but if you want the watch to last a lifetime the best chance of that happening is if the movement is clean, oiled and adjusted correctly... It still may quit, but so far, of the dozens and dozens of new and old Asian 7750's I have serviced, only 1 has been returned for warranty...and no one has told me that their movement quit after I serviced it... Anyone who has communicated with me knows I am very open and honest, so it's not like they would be afraid to let me know of a problem... You can always also go the route of installing a genuine ETA 7750, that can involve some work depending on what your replacing it with...ie standard 7750 layout is straight forward... Now your informed and can make an informed decision, to service or not to service, your choice, but at least you know what these movements are like when delivered. It makes no difference to me what anyone does, but since I sit at the bench and see what the condition of these movements is, it's my contribution to the forum to inform the members here of what I find... RG

Try this Starting info RG

www.ziggyinfo.com Or better yet, Google "Watch Repair Prices" and you'll get a good cross section of pricing... Check these guys out... Manual wind_______________________$75.00 Manual wind shockproof____________$80.00 Manual wind w/calendar____________$95.00 Automatic wind____________________$150.00 Automatic w/calender______________$175.00 Automatic chronometer_____________$750.00 i.e. 7750 Repair shop link... RG

This has been discussed many times... For what it's worth, I'll comment from what I see from the workbench. I have serviced dozens and dozens of Asian 7750's, both the older version and the new one. You can take my comments with a grain of salt or self serving, or you can consider them to be information from what is seen when a movement is opened up and looked at... What I see with every one is dry movements (i.e. no oil, not even in the balance cap jewels), and parts that are overoiled to the extreme... During the last year the dirt issue has been corrected, but these movements are still not oiled. Simple analagy: The reality is this, you can pay the watchmaker "Now" or "Later"...meaning a movement that you choose to let run with no oil and use it until it stops (because of worn/broken parts) will be more expensive or impossible to fix vs cleaning and oiling it as a preventive measure... Any watchmaker can clean and oil a watch and make it run...finding and replacing broken/worn parts - especially on an Asian model is next to impossible... In the end, it's a choice. You may want to keep the watch and not invest any money in maintaing it and when it breaks, throw it out and get a new one...nothing wrong with this if this is your way of doing things... Compare this to your car, how many here drive their car and never ever check or change the oil?? Would you drive your car until it broke and as your watchmaker said "dont' do anything until a problem arises..." and when the engine finally quits, do you think the repair bill is going to be the same, more, or less than changing the oil on a regular basis??? Here is what I find in Asian 7750's, NEW 28.8K models... It's a choice, and there is no right or wrong answer, but the reality is that these Asian 7750's are no where near serviced correctly when delivered...I see it all the time...now you know "the rest of the story..." RG

Eventhough the top button is working from the outside, I suspect it's not fully acutating the pusher on the movement... Even if you do open it, it's going to take some work to get it fixed, it may be best to simply get a local watchmaker to take care of it... RG

Just to clarify the calculations... HSS Twist Drill Recommended Speeds and Point Angles Type of Steel.............Point Angle.........SFM Steel < 180 HB..........118....................80-110 Steel 180-280 HB.......118....................45-70 Steel 280-380 HB.......135-140.............30-45 Steel >380 HB...........135-140..............15-25 Stainless Steels..........................Point Angle...........SFM Stainless steel 200-300 series......135-140...............20-40 Stainless steel 400 series and PH..118.....................30-60 RPM = SFM x (12/pi) Diameter of drill bit In my example I chose this, Stainless 300 series, and I chose the high end value of 40 SFM Drill bit #55 is 0.0520" diameter Plugging the variables into the formula 40 X (12/3.14) 0.052 40 X 3.82 0.052 152.8 0.052 = 2938 RPM Me thinks were onto something now, and will get good results... Bill shamed me into going to get myself a small drill press and start offering this service, although I have been doing some research for a few weeks with that idea in mind, he gave me the push I needed to do it. I dont' believe in half jobs, or guessing at this stuff, with this data it should be easy to do... RG

Well a year ago, after being a single dad for a number of years, I may have taken you up on the offer...but now I have a lady friend....so I am taken so to speak... Thanks for the pictures of the crowns and the dimensions etc...good info to have on hand. The difference between 0.25 and 0.30mm on my calipers while trying to measure the pitch is too small to note...and I had never seen an odd pitch so even if I had measured 0.30mm I would have assumed I was measuring it wrong... Great info, I have printed these out for reference to add to my library. RG

I have been doing some reading as well... Here is the formula for calculating drill bit speed... For Stainless Steel, 200-300 series, drill bit point angle is 135-140 degrees, and speed is 20-40 SFM (Surface Feet per Minute) For 400 series Stainless, point angle is 118 degrees, and SFM is 30-60 To convert SFM into something useful like RPM RPM = SFM x (12/pi) _________________ Diameter of drill bit So for a #55 drill, 0.0520 inches, we get 2900 RPM for the drill bit speed... If you used a 0.50 (1/2 inch drill) in the same formula, you get a speed of 300 RPM... The smaller the bit, the faster the speed to achieve the same SFM. The other interesting point, is that Stainless tends to "Case Harden" if drilled too SLOWLY...firm and steady cutting avoids this problem... RG

Excellent follow up and information, I wish they were all this easy... Most likely the pusher arm that starts and stops the chrono is defective, or for some reason not pushing the chrono cam enough. Have you tried pressing on the actual lever and see how it works, vs using the case pushers, does it "click" into each chrono position, i.e. start and stop... When you press the "top" or left lever in your picture, you should feel nice crisp clicks as the cam switches. Depending on your experience and skills you may be able to fix it, or get someone locally to fix it, it certainly does not warrant return to China for this problem... RG

Honestly, I am surprised... I never think of my posts or reviews as more than my way of providing insight to the members here. I put them out there for everyone to see and make their own informed decisions. Good, bad, or indifferent, I report what I see. Until someone else steps up and does the same from their perspective, I guess what I offer (and the feedback from Finepics and Vaccum) is all we have to go on... RG

I dont' buy anything from Ofrei, Bob Frei is a jerk to say the least... I am not sure of the pitch, I though it was 0.25mm at 3.00mm diameter, but you said it was 0.30mm pitch (I thought metric pitches ran in 0.25 increments). I am sure if you ask Cousins in UK they can tell you what one to use... RG

Common problem on the 7750, I see it quite often. The problem is the quickset gear does not move accross and engage the date wheel. It can sometimes be fixed, getting at the part required some disassembly of the dial side of the movement. RG

I have since worked on a few more of these models, and none of them had the hairspring problem. I want to stress again, this is a hairspring issue ONLY, and easy to fix or replace the entire balance. I find it strange that people are blacklisting this movement, when it can be fixed easily, yet they still go out and buy a Daytona with seconds at 6, and all the UNFIXABLE problems that movement has...strange... RG

Here is the detailed review on the new 7750... Asian 7750 @ 28.8K RG

This post shows in detail how to release and install the stem, it should help. How-to uncase a rollie...ETA A stem is a 401 part number, order it quoting the caliber number of the movement. RG

For all the time and money, why don't you just service the movement you have in the watch, and fix the problem for good... Installing an ETA, while a partial solution, still requires the ETA to be serviced and maintained...add that cost to the cost of the ETA, the cost of the install, new hands etc...and you can get your Asian serviced 2 times or more, and get 10 years of use from it... This movement has been revied in depth, with service there is no reason for it to not last as long as any ETA... RG

The hand resetting has nothing to do with the actual movement... It's a common well known problem on all models, rule of thumb, get the hand glued so it wont' slip, and never, ever, reset anywhere but between 10 and 2 on the dial face as it causes too much stress on the hand when it flys back to 12. RG

Probably neither... Turn the watch upside down, and I bet the stutter is now between 8 and 12... If it has a Miyota or copy Asian movement, it's normal... RG

So far so good, of all the tubes I have installed, not one case has stripped as a result of the tap being passed over the original threads. I think the pitch difference is so subtle, that is doesn't make a big difference. Worth having a tap on hand if you intend to do a few more, and given that the rep crowns and tubes tend to strip after a while, it will pay for itself. RG

I just run the tap through the case, and screw the new crown in... There is little else that can be done when the diamter is the same as the new one but the threads are a different pitch... My original post outlined a MBW and it was already 3mm but wrong pitch... all I did was run the tap through the case and it was fine. I do them all this way, as there is no other way to do it. RG

Sorry to hear about your loss... RG

You need to run a tap through the hole for the new crown tube to fit... This post covers it all... How to install a crown and tube... Ofrei sells the taps. RG

Great collection... I love that white dial, very nice. RG

I use GS Hypo Cement... For a few reasons, 1. It's got a fine tip for applying it, a few drops in the center area is all that's needed... 2. It dries slower than CA glue allowing alignment 3. And most important, if you get any of the glue on the dial face, it does not stick, you let it dry, and it peels right off... RG