Is There a Cure for What Ails the Secs @ 6 7750?

[freddy333]

This post is mostly directed at Ziggy, but anyone with a vested interest in the subject can chime in.

I have been brainstorming over possible remedies for the frequent problems plaguing many seconds at 6 7750 movements, such as those used in 1652xx Daytonas. In one of Ziggy's original reviews of this movement, he surmised that the likely reason the movements were installed with little or no oil was to counteract the additional load/drag on the motor caused by the additional gearing and thus allow the movement to run as freely and as long as possible (even light grades of oil add some degree of friction between adjoining surfaces).

So, if removing the oil in key locations of the gear train lowers the drag on the motor just enough to allow the movement to run (for an unknown duration) and adding the correct oil increases it causing the watch to stop running, I am wondering if there is something one could add to the oil to lower the friction coefficient below the threshold of no oil.

My belt drive stereo turntable's platter has a bearing that rides on a ceramic disc that is supposed to be coated with a 'vapor thin film of sewing machine or very light gauge oil'. And this works fine, except that a small amount of the vibrations generated by the stylus (needle) riding in a record groove migrates down the platter's bearing and into the bearing cylinder, where it can diffuse the sound (we are talking very minute, but audible effects here). So, many years ago, in an effort to tame these spurious vibrations, I started experimenting and found that the sound could be subtly improved by filling the entire bearing cylinder with heavier grades of oil (the best turned out to be 10W-40 motor oil), which effectively damped most of these errant vibrations.

Unfortunately, using so much thick oil came with a serious side-effect -- instead of taking about 3/4 of a revolution for the platter to come up to 33 1/3 rpm, it took many revolutions, or about 1 full minute, which all but foiled my otherwise brilliant plan.

So I had to figure out a way to reduce the increased friction and still be able to fill the bearing cylinder with 10W-40. I do not want to bore you with the details, but I found that mixing the oil with an off-the-shelf 'engine friction reducer' (not PTFE/Teflon) reduced the friction and the platter came up to speed in a little less than 3/4 of a revolution and still helped to quiet the vibrations.

So the question is whether you tried/considered or think something similar might be able to produce similar results in these seconds @ 6 7750s? Is there some type of lubricant that produces less friction than using no oil at all?

Ziggy?

[ubiquitous]

Is there a way to make the 7750/60@6:00 more reliable. My thoughts on this...

Perhaps if they added gears that are cut more precise and with lighter weight, that would help (the precision cut gears to take out the 'slack' in running). Perhaps a stronger mainspring... Maybe change the gear ratio to deliver better torque? Add some jewels at the pivot points for better wear...

[freddy333]

Ubi -- That was where my thinking began (plastic/nylon gears as used to be used in many older automobile clocks). But I think Ziggy said that the extra friction & drag was inherent in the additional gearing, so I did not think changing torque or gear materials would do the trick. Or at least that was my impression based on Ziggy's comments.

How about a thin sheet of teflon under each of the additional gears (think about that narrow teflon strip on Mach 3 razors)? Anyone who uses a Mach 3 razor knows how much more easily it slides on your face compared to a standard razor without the teflon strip. And you could grind down the side of each gear that rides on the teflon to maintain the original gear train height & alignment. This would have a secondary benefit of reducing each gear's mass, thus lowering the overall drag on the motor even more.

The more I think about it (and how simple it would be to implement), the more I think it would be worth getting Ziggy's input.

[gran]

I wonder what The Zigmeister wil say about all of this there is always a solution.....

[freddy333]

there is always a solution.....

Yes, I agree. So I wonder why Ziggy simply concluded that these movements were destined for failure without offering much in the way of a permanent fix for owners.

[RWG Technical]

My view is that there is a simple and easily done solution to this problem, the problem is that I can't do the fix...it has to be done at the source at the manufacturing level.

IF they were to make the transfer gears (all 11 of them) pivot as per normal watch standards, in other words, have each gear with pivots turning in jewels, that would fix the problem. That's all there is to it.

The other design change would be to run the 12 hour counter accross the dial face with the 5 gears, and the running seconds directly from the 9 position to the 6 one, with 3 gears (not the present 5 gears). The 12 hour gear runs directly off the mainspring barrel, so it has a lot of torque, and runs very slow so added friction is not a concern.

Using a lighter lube will not correct the issue, just think of all the non-serviced 7750's that have been reported as failing...these are not oiled at all, and don't work. So I think no oil, or lighter oil, is not a fix.

It would be so easy to make a 100% reliable movement, sadly I don't have the skills or tooling to do it.

Larger mainsprings won't work, the mainspring has to be what it is now, a larger one would cause overbanking and the movement would fail.

I can't understand why they can't make such small design changes, to change the movement from unreliable, to perfect. The same goes for the cannon gears, they are all terrible on the A7750, yet so easy to make it right...same for the pallet stones, falling out all the time and not attached to the fork...I glue them in place during a service, why doesnt' the manufacturer glue them in when they make them, the glue is there, it just doesn't work...etc...etc...etc...

One afternoon with the manufacturer, and I think we could produce a wonderful movement, the chances of that happening are slim to none.

RG

[freddy333]

Hey RG -- Good to hear from you and thanks for your input.

At the risk of beating a possibly dead horse, what do you think about using teflon as I suggested and trimming the gears that ride on it? At least in lieu of a more formal solution by the factories that make the movements.

[RWG Technical]

Hey RG -- Good to hear from you and thanks for your input.

At the risk of beating a possibly dead horse, what do you think about using teflon as I suggested and trimming the gears that ride on it? At least in lieu of a more formal solution by the factories that make the movements.

I think the way the design is laid out now, with the transfer gears running on small metal thin raised rings, without lube, is the least friction you can have... Teflon I think would have to much friction. There would be no way to trim the gears, as they lay flat on the bridges and mainplate and run on the whole surface. Not sure if you have seen one in pieces, but the posts are only there to keep the gears in place, the posts are not normal pivots. There are also only a couple of jewels for all the 11 gears, and even at that, the jewels are totally useless, as the gears run on themselves, not on the non-existant pivots...

I have tried everything, including popping out all the riveted gears (3 of them), cleaning them throughly, adding a black oiler drop of 9010, reassembling in the jewel press, and getting the rivet and gear to just the exact fit so there is no sideshake, but perfect freedom...hours literally of fine tuning adjustments, yet to no avail...sometimes it works, but most times, it's a failure. So I gave up, now after service, I try the transfer gears, any problems on the vibrograph, and out come the gears and I freeze the running seconds.

RG

[gran]

sad story indeed

@RG

Since this problem obviously will not be (properly) fixed with the present setup..

Let me ask something even more horrendous just for the fun of it. Would it be possible to design a belt or several small belts to help out the situation (instead of using only gears)?

[FxrAndy]

i bet Tag could after looking at their V4

[b16a2]

Hopefully i the future we may see the introduction of such a movement. Just a year ago, the @ 6 seconds movement was a fantasy, something that we would have beheld as a massive breakthrough. Maybe in time, we will see a new movement, here's hoping!

[rek001]

Time to start a collection drive for The Zigmeister's round trip ticket to China

[ubiquitous]

So... In the end, we have a movement that needs major revision, and even after that (if it would ever happen), it's still too thick for a proper Daytona case.

Though, other 60@6:00 models may benefit... And maybe cross pollenate to other layouts where 60 runs at 12:00 or 3:00...

[RWG Technical]

sad story indeed

@RG

Since this problem obviously will not be (properly) fixed with the present setup..

Let me ask something even more horrendous just for the fun of it. Would it be possible to design a belt or several small belts to help out the situation (instead of using only gears)?

I have never heard of any watch with any sort of belt in them for drive...my initial guess would be that the belt and pully would have too much resistance and not work either.

Getting the movement re-designed with correct -watch engineered gears- is the fix, if only they would do it.

I would love to see how the rolex is designed, since the placement of the seconds is a direct function of where the winding stem is located, which in turn locates the balance, which then dictates the placement of the second gear. I still haven't figured out how they did it...maybe someday Ubi will trade in those franken El Primero's and get a real Daytona I can have fun with...

RG