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Omega cal.t17 help


Oyster

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Hi folks , I’m working on the Omega t17 that have a really strange problem, if i wind it to full power it seems to run like crazy with mad reading , but if i wind it ..say 5-7 time it keep the rate better , also the amplitude is almost the same on 5-7 turn and full turn at 290-320 

i attaches the photo of the read 

I also noted that the beat rate is expanding and close on the reading too, Balance swings is not even ?

thanks for the read and answer!

D15E0B4F-DD7B-4D00-AE09-45486EB0FBF2.jpeg

6EBB2854-8109-41DB-BF45-BF518DBB5855.jpeg

173C1569-0778-4F07-A37D-EC41F488BBA6.jpeg

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Broken/worn pivot or jewel on the balance fork?

Broken or worn pivot or missing/poor spring on balance, or damaged balance jewels?

Is it worse in some orientations than others?

I had something similar on a watch recently, and the pivot on the top of the balance staff was worn to a small nub. The moment you moved the watch, it was all over the place, but if you kept it still, dial down, it ran perfectly. I replaced the balance, simply because I already had a donor movement, and it ran perfectly.

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56 minutes ago, AndyHull said:

Broken/worn pivot or jewel on the balance fork?

Broken or worn pivot or missing/poor spring on balance, or damaged balance jewels?

Is it worse in some orientations than others?

I had something similar on a watch recently, and the pivot on the top of the balance staff was worn to a small nub. The moment you moved the watch, it was all over the place, but if you kept it still, dial down, it ran perfectly. I replaced the balance, simply because I already had a donor movement, and it ran perfectly.

Checked everything and it looks good and in good shape, could it be the wrong mainspring  size ? I believe t17 can hold up to 3 days power

also if is the pivot , might be super hard to find parts

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Well, the rate of oscillation is drastically increased, so if it's not knocking then I would inspect the hairspring for touching anything as it breathes open and closed.

Is it very sudden when the rate increases? If re-banking then it usually suddenly happens at a given maximum angle of rotation which will be in the region of 330 degrees. Is your lift angle set correctly too?

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12 hours ago, rodabod said:

Well, the rate of oscillation is drastically increased, so if it's not knocking then I would inspect the hairspring for touching anything as it breathes open and closed.

Is it very sudden when the rate increases? If re-banking then it usually suddenly happens at a given maximum angle of rotation which will be in the region of 330 degrees. Is your lift angle set correctly too?

I think you’re right, is a rebanking .

i lubricant the escape wheel and pallet jewel with d5 to slow in down , and with full wind the beat got control, (not that good) but ware able 

thanks a million !

image.jpg

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  • 4 years later...

This thread is quite old, but since I'm also doon going to service a T17, I wonder what mainspring size you used? 

Online, I found a picture of a Bestfit mainspring for the T17 with the measurements  1.4 x 0.09 x 343. CousinsUK mentions the GR3632 mainspring as suitable for the T17 and it measures 1.40 x .09 x 360 x 10. 

Cheers! 

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  • 6 months later...

Hello all and hello @Oyster,

So, this is interesting.

I ordered the GR 3632 and I didn't manage to get it into the barrel... it was ever so slightly too big. A bit strange. But that's not the main thing I want to share.

Since I couldn't get the 10mm diameter mainspring into the barrel, I was looking very hard for a 9.5mm mainspring with similar height/thickness/length.

I found GR3937 with 1.45 x .085 x 380 x 9.5.

Three things:

1. It's a tad longer, so I'm hoping to get an amazing power reserve.

2. It's a bit higher than GR 3632, which had me a bit worried, but it does fit (just!). I had also found one link where 1.45 is actually specified as the correct height for the T17.

image.thumb.png.27a540bf18e3b764fdaa488d15d7af32.png

 

3. It's a bit thinner than the GR3632. I believe to understand that mainspring power/torque is a function of "height" x "thickness"-squared. Thus, power of GR 3632 would be 1.4 x 0.09^2 = 0.01134 , whereas the GR 3937 is 1.45 x 0.085^2 = 0.01048. So the GR 3937 is about 7-8% weaker.

 

So after using GR 3937 and oiling only the balance (and the barrel), I'm already getting over 300° amplitude!

So I ended up using HP 1300 on the whole train and 9020 (instead of 9010) on the escape wheel. 

I'ts running at around 315° amplitude now.

 

CONCLUSION:

WHY all this long story?

I'm just saying the the modern GR mainsprings that are indicated for very old calibres, can easily be over-powered.

In your case, I'm certain that's the case. If I had 7-8% more torque from the stornger mainspring (and used thinner oils for the train), I'm sure my T17 would also be knocking.

 

 

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On 3/2/2024 at 11:50 PM, Knebo said:

Since I couldn't get the 10mm diameter mainspring into the barrel, I was looking very hard for a 9.5mm mainspring with similar height/thickness/length.

I am sorry, I can't underrtand what is writen here. Actually, I understand, but it sounds like a nonsence to me. There is a plenty of space in the barrel, it usually can take almost 2X longer spring with the same 'strenght' dimension.

Othervice, I agre that modern springs often are 'stronger' than needed.

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Hey @nevenbekriev,

I'm referring to the barrel diameter of 10.0 vs 9.5mm, not the mainspring length. The barrel diameter is the last number indicated for GR mainsprings. 

Since I don't have a mainspring winder, so I rely on the GR mainspring to fit from the retention ring straight into the barrel. The one at 10mm wouldn't do that. Too large in diameter (not length). 9.5mm was just fine. And ot had all the power and length that I could need. 

Hope that clarifies. 

Cheers

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On 3/2/2024 at 1:50 PM, Knebo said:

10mm diameter mainspring into the barrel

you do know that the barrel diameter listing for new main Springs is more of ease of pushing it in versus an actual specification.

2 hours ago, nevenbekriev said:

A, now I see, it was the ring that holds the spring... Othervice, no problem to put the GR spring in the barrel, even if the barrel size was 7mm

which is exactly what is quoted here if you have a mainspring winder you could just take it out of the ring and put it in and it be fine providing all the rest the dimensions are what they're supposed to be..

then from the bestfit book we get this

image.png.24d642fb42a5d5c89d105761776d12b1.png

notice the bestfit book does not list the ring size of the mainspring is Internet's only a relatively recent development. Now the most interesting number is the 512 P which we can find here

image.png.e0181d00ba238e1fd6f49c541e690713.png

if I did my math right about 330 mm for the length.

On 3/2/2024 at 1:50 PM, Knebo said:

I ordered the GR 3632 and I didn't manage to get it into the barrel... it was ever so slightly too big. A bit strange. But that's not the main thing I want to share.

image.png.06b2593632455631a68dbfb0393cd875.png

a lot of times on mainsprings you will see length variations by a little bit it doesn't matter. Plus at the mainspring is a fractional millimeter like 0.05 on time so just drop it down to an even number as it's not a matter very much at all.

On 3/2/2024 at 1:50 PM, Knebo said:

3. It's a bit thinner than the GR3632. I believe to understand that mainspring power/torque is a function of "height" x "thickness"-squared. Thus, power of GR 3632 would be 1.4 x 0.09^2 = 0.01134 , whereas the GR 3937 is 1.45 x 0.085^2 = 0.01048. So the GR 3937 is about 7-8% weaker.

 

So after using GR 3937 and oiling only the balance (and the barrel), I'm already getting over 300° amplitude!

So I ended up using HP 1300 on the whole train and 9020 (instead of 9010) on the escape wheel. 

I'ts running at around 315° amplitude now.

 

CONCLUSION:

WHY all this long story?

I'm just saying the the modern GR mainsprings that are indicated for very old calibres, can easily be over-powered.

one of the theories is that the original blued steel mainspring doesn't have the same power as a modern white spring or the modern Springs.

The other thing I'd be curious about is what is the lift angle of this watch as the pallet fork is in a strange angle I wonder if that changes the lift angle at all?

On 3/2/2024 at 1:50 PM, Knebo said:

If I had 7-8% more torque from the stornger mainspring (and used thinner oils for the train), I'm sure my T17 would also be knocking.

the reality is you're probably using heavier oils than what was originally specified. If you look at the really early Omega documentation and anything with organic oils they are usually much thinner than the modern lubrication's.

 

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  • 2 weeks later...

 

On 3/11/2024 at 8:40 AM, JohnR725 said:

you do know that the barrel diameter listing for new main Springs is more of ease of pushing it in versus an actual specification

Yes, I understand that indeed.

 

On 3/11/2024 at 8:40 AM, JohnR725 said:

if you have a mainspring winder

Which is exactly what I am lacking, as I said. That's why the ring diameter matters to me.

 

On 3/11/2024 at 8:40 AM, JohnR725 said:

one of the theories is that the original blued steel mainspring doesn't have the same power as a modern white spring or the modern Springs

That matches my anecdotal observation indeed. It could be the material or the modern backward curve that provides more power.

 

On 3/11/2024 at 8:40 AM, JohnR725 said:

the reality is you're probably using heavier oils than what was originally specified. If you look at the really early Omega documentation and anything with organic oils they are usually much thinner than the modern lubrication's.

This is an interesting topic! 

While these old oils were maybe thinner, their friction-reducing effect may still actually be lower than modern (even thicker oils), no?

I man, some old, thin, organic oil may be less effective in reducing friction than a modern, thick HP1300 or so. What do you think?

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2 minutes ago, Knebo said:

While these old oils were maybe thinner, their friction-reducing effect may still actually be lower than modern (even thicker oils), no?

I man, some old, thin, organic oil may be less effective in reducing friction than a modern, thick HP1300 or so. What do you think?

I remember when I was in school the instructor would use whale oil on some problematic little tiny ladies watches because he felt it was a better oil.

then for my birthday on my friends gave me a bottle of vintage nye watch oil. Complete with the advertisement inside which I have scanned below and what I find interesting is it hasn't gone bad in the model and it is super super thin I'm guessing the viscosity of water basically.

then somewhere in the discussion group within the last year or so somebody purchased one of these bottles off of eBay and was using it on their watch. After all a bottle watch oil is? Apparently it was an expensive I'm guessing or it's what they had or something no idea what the final outcome was other than I found it amusing.

image.thumb.png.98feb53b55cccdf457e2cfcadff30275.png

then somewhere in the Internet somewhat it made up this interesting chart down below. I believe the first natural oil is there 8000 oil. Notice the friction properties in the first two columns in other words it's really good at reducing friction better than anything else.  But it does have additional specifications like contact angle which is almost never found in any spec sheet which has to do with how likely it is to spread. Big numbers are bad in those two columns and you can see spreading test it's very bad. So basically it's a really outstanding oil for a short period of time before it spreads away and of course being natural it has a habit of probably going bad very soon

the best oil of course is Elgin oil at least the second version of their oil very good at reducing friction and very good at staying wherever you place it and still very fluid oil viscosity wise.

then one of the most famous oils of all Swiss 9010 that I personally don't like and don't use quite a ways down on the chart personally prefer 9020 which unfortunately is not listed on this chart. It slightly heavier viscosity and has a little nicer contact angle those more likely to stay wherever you put it versus 9010 which universally requires epilam if you would like to stay wherever you putting it.

image.png.acdb5005d777d5ba43277ff11fa7b4e3.png

then if you're in the viscosities here's an interesting chart that I found on the discussion group. ou will note there some minor variations between the viscosities listed here and the chart up above which may be attributed to the difference in temperature  universally everything is supposed to be at 20° C and the chart up above is at 40° C.

Because what becomes interesting on the chart is 8000 is listed out of viscosity of 95 which does agree with their technical information and the PDF for the oil lists at 40° it is 41 where up above the chart everything is either listed as 50 or light whatever that means? Then Elgin oil is listed on the chart in a clever interesting way. you look on the chart at a viscosity of 125 you'll find Dr. Tillwich LGN oil which is the synthetic version of Elgin oil. Many years ago they had a request and gathered up a whole bunch of samples and synthesize the oil and for a while it was available for sale although it was rather expensive I had seen a bottle for about $100. and as far as viscosities go it does appear to be right in both charts in other words at 20° it's 125 and at 40° it's 50.

So unfortunately it brings up the problem of viscosity or better yet contact angle determines the spread ability of your lubrication unfortunately we typically don't get contact angle we just get viscosity. So the casual trend is a heavier oil tends to not spread although as we can see from looking at the chart that isn't hundred percent true. As far as reducing friction goes viscosity doesn't necessarily come into play here either. Or basically we don't have enough of the right tech sheets to make a real proper comparison.

image.png

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