Check the running rates with crown up, down, dial up and down..
August 12 2012, 1:39 PM
You will find that Tudor having the inaccurate cheaper curb pin balance system, that the running rates are far apart in four positions.
That is why a Rolex Micro Stella balance system has fantastic vertical to horizontal running rates.
The inaccuracy of all Tudor calibers results in the fact that a curb pins touch the hairspring, while the Micro Stella free sprung hair spring has no friction points and has mean screws for more accuracy. One hard hit on any curb pin balance system the regulator slides out of position and readjusting is required.
Not ture at all..I have tested a lot of curb pin calibers..
August 12 2012, 4:33 PM
New and old...they do not hold a candle to a free sprung Micro Stella layout.
Why do you think all the top calibers have a hair spring which is free sprung with a type of mean screw layout? Far more accurate system. Less positional error due to gravity pulling on the hair spring rubbing on a curb pin and lacks a real trued balance rim with mean weights to take out any imbalance.
The cheaper curb pin system has a smooth balance rim and is a nightmare to true. I have tried for years to balance a smooth rim. I had to drill into the rim to take weight off in order to take out flat spots. To much material out, rim becomes no good. The curb pin regulator system is why outdated and no adjustment is built in to make a super accurate caliber. Ancient by high end standards.
Take the 727 Valjeux. Rolex tossed the antiquated curb pin system and reworked a Rolex Micro Stella free hair spring system. The kicker was that the SS Daytona was not submitted for chronometer testing, but in essence was and still is deadly accurate for a manual wind caliber because of the balance system.
This message has been edited by aakviper from IP address 188.8.131.52 on Aug 12, 2012 4:38 PM
Once again I agree in theory...but it is not always the case.
August 12 2012, 5:15 PM
Those hairsprings are so stiff they hardly change position when placed stem up or stem down. You should work with a 30's spring.... They are made of peanut butter in comparison.
Perfectly centered between the pins dial up and turn it stem down and it may change the BEAT by 2 milliseconds and the spring can completely REST on the pins with just the gravity of the coils in play.
I'm saying I agree with you....but to say that you can't get a fantastic and consistent reading out of a non free sprung balance is not true either.
I know you are quite the advocate of the free sprung system and I agree with you that it is in theory a superior design and is more advanced....but some would say the same of a Breguet overcoil...however Rolex's most accurate movement uses a flat spring and it is miserable to work on...because of the silly lack of attaching stud on the HS.
The microstella system is much easier to get accurate results because there are less
August 12 2012, 9:02 PM
factors coming in to play. You can still get excellent results with calibres containing regulator pins, it just takes a little longer. I have sometimes seen better timing results from a 1520 (pins) compared to a 1570 (free sprung), it just depends on how the pins are adjusted. You have to make sure the hairspring is completely centred between the pins (hairspring not touching either pin) with balance in resting position. Then you have to adjust the distance between the pins so that the rate is similar when the watch is running at both fully wound and at half wound. This is because the amplitude will reduce at half wind. If the rate drops at half wind, you have to close the pins a little then test full and half wind again. Another indication is if the rate drops a lot in vertical positions because the amplitude is lower. Once again, reduce the distance between the two pins. Of course, there can be more factors that come in to play but this is the basic idea. With everything set-up perfectly on regulator pins, I have seen a rate difference of less than 5 seconds in 5 different positions. I have even seen it as low as 2 seconds difference.
you failed to mention any work done to the balance wheel.
August 13 2012, 9:11 AM
50% of accuracy on any balance is a trued balance wheel.
Also the hair spring does what we call "breathing" and does touch a pin at some point of the flexing action. One should never adjust the distance between the pins more then once if the hairspring is completely centered between the pins. The curb pin function is to set up a balance pose from the energy from gear train via mainspring. That is where amplitude is created and translated. By you having to close the pins a little then test full and half wind again, your hairspring was not correctly centered or set up. You should take the caliber to a watchmaker to set up a centered hair spring to curb pin alignment.
I am surprised that you failed too mention an important aspect regarding centering the hair spring. The collet and hair spring bend relationship is 100% important to a vertical centering of the curb pin. Without that step a true center can not be accomplished.
Now another false statement is that amplitude will reduce at half wind and the rate drops at half wind. If you have a healthy and cleaned caliber, all the pivots are lubricated correctly, mainspring has the correct tension in the barrel and so on, a 50% mainspring amplitude will not significantly change in the running rates. Some loss in the amplitude, but maybe a one or two second in positional error. I have tested this fact many times.
One other important aspect to the poor performance of a curb pin balance set up is the metal to metal fatigue encountered from the rubbing of the hair spring to curb pin surface. Inside of a year or so if one would look under a high powered loupe you actuality see a grove like area appear from this wear on the curb pins and hair spring. This has an effect on positional error over time by adding more friction in the hair spring movement.
So that rate of the 1520 caliber difference of less than 5 seconds in 5 different positions. which you have even seen it as low as 2 seconds difference as you laid claim to will not be so in a years time. Now the 1570 caliber with free sprung balance will be still spot on.
Ask any watchmaker at a Rolex service center or local watchmaker, and they will tell you a curb pin regulator set up has a limited positional accuracy compared to a free sprung balance with mean screw set up. That is why one pays more for the later in the cost of the watch.
From your example a 1520 caliber can never match the 1570 positional accuracy in the long term. The 1520 is not with it's balance c-clips and curb pin regulator set up a long term accuracy caliber as the Micro Stella free sprung layout design.
This message has been edited by aakviper from IP address 184.108.40.206 on Aug 13, 2012 9:14 AM
I failed to mention page of factors in regards to timing a watch.
August 13 2012, 4:13 PM
I didn't want to bore everyone with the science involved in timing. When talking about the regulator pins, I was considering a true and poised balance. Because, you would only make adjustments to the hairspring after being sure that the balance is true and poised anyway. Otherwise, it's like doing it in the dark. My statement about amplitude loss is true. All watches I remember servicing (in Rolex service centre), the amplitude will drop when tested at half wind or after 24 hours. If the pins are too far apart, there will be a rate loss with loss of amplitude. Actually, one of the tests we do is to test the amplitude and rate at full wind and half wind. Isochronism is what we are trying to achieve. This term refers to a stable rate regardless of amplitude. I won't even start about the relationship with the pallet fork and roller.
true and poised balance is not done by Rolex or any other watchmaker..That is one huge drawback with any curb pin balance.
I tested not to long ago one of my Tudor MC with a Valjeux 234 fast beat caliber at full and half wind. The amp drop was from 260 at full wind to 248 amp..Not a significant drop and the pins relation to the hairspring was not effected. Once you center a hair spring curb pin layout, the amplitude loss is from the mainspring uncoiling energy not from a properly set up balance,
Now your statement "If the pins are too far apart, there will be a rate loss with loss of amplitude" This loss would also be seen on the watch timer from a full wind as well. You are bring up a short coming of a ill property set up hair spring to curb pin distance to begin with. A properly centered balance to curb pin set up will yield a very little rate and amp loss ay half wind.
This message has been edited by aakviper from IP address 220.127.116.11 on Aug 14, 2012 8:25 AM This message has been edited by aakviper from IP address 18.104.22.168 on Aug 14, 2012 8:24 AM This message has been edited by aakviper from IP address 22.214.171.124 on Aug 14, 2012 8:23 AM
I've usually found that a 0 timing offset on a timer results in...
August 12 2012, 9:38 PM
...slow time-keeping on the wrist. I think you'll find that setting the watch somewhere between ~+10~+20 secs on the timer will result in more accurate time-keeping on the wrist. Of course, your wrist mileage may vary.