Origine Live upgrade belt for Thorens

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tele88
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Re: Origine Live upgrade belt for Thorens

Post by tele88 » 12 Nov 2015 18:27

ddarch wrote:Disappointed to report OL would not provide me with free sample belts for 160 and 125. Here I am selling over a 100 vintage Thorens turntables a year, buying 1-2 Motor kits from OL a month the past six months, and they won't send me a couple of belts to review? (Not to mention I've got 3500 followers on Facebook and had over 100,000 views of my DIY vids on Youtube)

Oh well...their loss. I'm perfectly happy using the Thorens logo belts for which I am a dealer and for which I never have anything but 100% complete success.

Dave

Interesting David I just ordered a belt for the TD160 and TD124 to do some testing concerning speed.
Since you are selling as much Thorens tables how are your results with the original Thorens belt and the Thakker ?
By the way OL said that the thickness has no influence on the speed !

ddarch
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Re: Origine Live upgrade belt for Thorens

Post by ddarch » 13 Nov 2015 21:33

Never used the Thakker.

Thickness no influence on speed? Ridiculous...of course, it does. Maybe they mean because they have accommodated for it in the different lengths????

sec4aa
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Re: Origine Live upgrade belt for Thorens

Post by sec4aa » 15 Nov 2015 02:53

Going back to rkay5 speed problem…the 538mm OL belt runs 1.9% faster than a Thorens belt based on his observations. The thickness of the belt is very important because a variation of just +0.2mm in thickness will increase the speed with approx 1.5%. This is be based on 60Hz at 33.33rpm (considering a sub-platter diam of 160mm, pulley diam of 11mm (not very sure about this one), standard belt thickness of 0.8mm and motor spinning at 450rpm). Now, rkay5 might be correct that a smaller belt (520mm) might work in theory, even if the belt length is nowhere part of the equation. I think that a smaller belt might stretch a bit and reduce the thickness under load…or maybe is just the extra tension on the bearing that will make things slower for a couple of weeks.

Obscurist
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Re: Origine Live upgrade belt for Thorens

Post by Obscurist » 20 Nov 2015 15:30

tele88 wrote:
ddarch wrote:Disappointed to report OL would not provide me with free sample belts for 160 and 125. Here I am selling over a 100 vintage Thorens turntables a year, buying 1-2 Motor kits from OL a month the past six months, and they won't send me a couple of belts to review? (Not to mention I've got 3500 followers on Facebook and had over 100,000 views of my DIY vids on Youtube)

Oh well...their loss. I'm perfectly happy using the Thorens logo belts for which I am a dealer and for which I never have anything but 100% complete success.

Dave

Interesting David I just ordered a belt for the TD160 and TD124 to do some testing concerning speed.
Since you are selling as much Thorens tables how are your results with the original Thorens belt and the Thakker ?
By the way OL said that the thickness has no influence on the speed !
Hang on, forgive me for this 'Physics-Noob' question, but I'm really confused now about the thickness of the belt influencing the speed.

As far as I can see, using common sense rather than knowledge, the speed of the TT-platter is determined bij the ratio between the circumference of the pulley and the circumference of the (sub)platter, with the pulley running at a certain speed. I made a graphic image to explain why I think that the thickness of the belt has no direct correlation to the speed of the platter.

When you look at the pulley (left, black) the length of certain part of the circumference (I used a quarter) is much smaller than the same quarter section on the (sub)platter (black, right), and therefor the bigger (sub)platter turns at a much lower speed than the pulley. I think the equation is Pulley Ø divided by Platter Ø = X and Pulley speed times X = Platter speed. Right?

Take a look at the platter on the right, where I called the length of that quarter section A > A'
Now look at the thin belt (green), where B > B' is only slightly longer than A > A'
And finally look at a very thick belt (red) where C > C' is quite a bit longer than B > B' and A > A'

The way I see it (but I may be wrong) is like this; the speed of the belt measured on the outside (C > C' or even B > B') will certainly be higher than the speed measured on the inside (A > A') because the outside travels a larger distance in the same amount of time, but no matter how thick you make the belt, the speed of A > A' will always be the same because the ratio between the circumferences of the Pulley and the Platter does not change, nor does the speed of the pulley (well, at least theoretically, a very tight belt may cause drag from the bearing). If the belt would be a chain, like on a bicycle, the outcome would be the same I guess...

Is my logic flawed? If so, please enlighten me. In simple language please: I'm a physics-noob, remember? :lol: If you use all kinds of funny equations I probably wouldn't understand half of it.
Belt_Thickness.jpg
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ddarch
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Re: Origine Live upgrade belt for Thorens

Post by ddarch » 20 Nov 2015 17:00

My initial thought is that the thickness affects the stretchiness/pliability of the belt. A thicker belt (in general) would not stretch as easily as a thinner belt, thus being more tight, the thicker belt would result in a higher speed. So, your logic is correct, but it doesn't take into account that different belts have different rates of stretchiness. Even different rubber belts have different stretchiness as well, though. So two belts that measure the exact same length could perform differently because of the quality and/or blend of the rubber.

tele88
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Re: Origine Live upgrade belt for Thorens

Post by tele88 » 20 Nov 2015 20:57

From Basis Audio a good explanation :


BELT THICKNESS AFFECTS SPEED
Careful analysis of flexible drive belts will show that the effective radius of a pulley is the measurement from
the center of the pulley to the neutral axis of the flexible belt (plane in the belt where stress is zero as it is
curved around the pulley), which is near, but not exactly at, the center of the belt. Simply stated, the thickness
of the belt factors into the calculation of the drive ratio of the pulley and platter. The ramifications of this are
numerous:
1. Different thickness belts will cause the driven pulley (platter) to run at different speeds.
2. Changes in thickness along the length of a belt will modulate the speed of the platter.
3. Round cross-section belts will attempt to roll in order to achieve the lowest potential energy state, in
addition to their scuffing action and increased propensity to hunt.
4. Any splice in a belt changes the effective radius as well as stiffness, causing spikes in the critical measured
parameters of wow, flutter, and drift.
As a result of the above facts, perfecting the belt drive turntable must first include perfecting the drive belt itself.


Practicality for the Thorens TD 160 turntable :

Motor speed 375 rpm. Motor pulley 13.71 mm Innerplatter 160 mm

The drive ratio is 11,67 !

Back from the motor 375/33,33 rpm we get 11,25 drive ratio target !

Speed 375 rpm/11,67 = 32,13 rpm if the tickness has no effect on the speed this turntable runs to slow !

Now we add the effective belt tickness to the motorpulley diameter which has the most impact on the drive ratio.

If we take eff.tickness from a 0.7 mm belt as 0.4 mm we get :

transmission 11.3 gives 375/11.3 =33,18 rpm to slow

effective thickness from a 0.7mm belt as 0.5 we get

transmission 11,2 gives 375 /11.26 =33,30 rpm

In the math we can see that the tickness has influence on the speed remember this changes with the stretching under load.

Wow and flutter are highly dependent on the quality of the belt.

Belts from OL are on the way.

Jaap

sec4aa
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Re: Origine Live upgrade belt for Thorens

Post by sec4aa » 20 Nov 2015 21:15

I think the formula for a rubber belt is simple:
(Subplatter diam + belt tick)/(pulley diam + belt tick) = pulley rpm / subplatter rpm
that is because in real world effective diameters of the pulley and platter include part of the belt thickness.

Obscurist
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Re: Origine Live upgrade belt for Thorens

Post by Obscurist » 20 Nov 2015 22:44

tele88 wrote:From Basis Audio a good explanation :


BELT THICKNESS AFFECTS SPEED
Careful analysis of flexible drive belts will show that the effective radius of a pulley is the measurement from
the center of the pulley to the neutral axis of the flexible belt (plane in the belt where stress is zero as it is
curved around the pulley), which is near, but not exactly at, the center of the belt. Simply stated, the thickness
of the belt factors into the calculation of the drive ratio of the pulley and platter. The ramifications of this are
numerous:
1. Different thickness belts will cause the driven pulley (platter) to run at different speeds.
2. Changes in thickness along the length of a belt will modulate the speed of the platter.
3. Round cross-section belts will attempt to roll in order to achieve the lowest potential energy state, in
addition to their scuffing action and increased propensity to hunt.
4. Any splice in a belt changes the effective radius as well as stiffness, causing spikes in the critical measured
parameters of wow, flutter, and drift.
As a result of the above facts, perfecting the belt drive turntable must first include perfecting the drive belt itself.


Practicality for the Thorens TD 160 turntable :

Motor speed 375 rpm. Motor pulley 13.71 mm Innerplatter 160 mm

The drive ratio is 11,67 !

Back from the motor 375/33,33 rpm we get 11,25 drive ratio target !

Speed 375 rpm/11,67 = 32,13 rpm if the tickness has no effect on the speed this turntable runs to slow !

Now we add the effective belt tickness to the motorpulley diameter which has the most impact on the drive ratio.

If we take eff.tickness from a 0.7 mm belt as 0.4 mm we get :

transmission 11.3 gives 375/11.3 =33,18 rpm to slow

effective thickness from a 0.7mm belt as 0.5 we get

transmission 11,2 gives 375 /11.26 =33,30 rpm

In the math we can see that the tickness has influence on the speed remember this changes with the stretching under load.

Wow and flutter are highly dependent on the quality of the belt.

Belts from OL are on the way.

Jaap
Thanks Jaap, now I understand where my theory is flawed #-o

What I assumed was that the inner side of the belt that touches the pulley and the platter dictates the speed, but in fact the part that does that in my drawing could well be somewhere halfway in the red area... Hmm...interesting. Luckily, my TD125 has the speed adjustment slider and the strobo :lol:

Ah, how nice, lived another day, acquired a new piece of knowledge...

tele88
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Re: Origine Live upgrade belt for Thorens

Post by tele88 » 21 Nov 2015 08:25

sec4aa wrote:I think the formula for a rubber belt is simple:
(Subplatter diam + belt tick)/(pulley diam + belt tick) = pulley rpm / subplatter rpm
that is because in real world effective diameters of the pulley and platter include part of the belt thickness.

Not that simple you forget the effective belt thickness! A rubber belt is not a string it stretch and so thickness varies !

Jaap

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Re: Origine Live upgrade belt for Thorens

Post by sec4aa » 21 Nov 2015 15:17

If you read some of my earlier posts here you will see that I addressed this effective thickness of rubber belts somewhere. The formula is a very good start since the elasticity coefficients are unknown for the given materials...I was using it just to point out that a 0.2mm variation in thickness has a 1.5% impact in platter speed. Now, this is nothing to go crazy about, because even the TD 160 and TD 145 have a "built-in adjustment". The pulley is not a perfect cylinder and by tilting the motor you can actually have the belt running at a different diameter...the adjustment is very small, but it can compensate for a 1.5%.

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Re: Origine Live upgrade belt for Thorens

Post by sec4aa » 22 Nov 2015 01:42

I was able to play with the azimuth screw today and all I got from it was an adjustment of 0.2 rpm running on 33.3 rpm. The azimuth adjustment main purpose is to make sure that the belt doesn't run up or down the pulley but it can be used for small rpm adjustments. Having the correct belt on a Thorens TD 160 TD 145 is crucial. I have different belts with logo, without logo, new or more than 2 yo and the speed variations on same settings are from 33.1 to 33.7. I have used the rpm calculator app...I don't believe the values are absolute accurate but they are a good indications of the rpm spectrum.

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Re: Origine Live upgrade belt for Thorens

Post by old70 » 02 Dec 2015 15:20

Obscurist,

I've tried the Origin Live Thorens TD125 belt and I confirm that 560 mm is too long. The belt don't even stay in place. I mesured mine (524 mm)and reread Joël Boutreux service manual. Last page, penultimate paragraph in french: "Longueur idéale pour la TD125 est de 260 mm (Plier en deux)". Translation: the ideal lenght for the TD125 belt is 260 mm (folded in half).

I'll return the belt to Origin Live and exchange it for one of the proper lenght.

Bert

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Re: Origine Live upgrade belt for Thorens

Post by Obscurist » 06 Dec 2015 18:24

old70 wrote:Obscurist,

I've tried the Origin Live Thorens TD125 belt and I confirm that 560 mm is too long. The belt don't even stay in place. I mesured mine (524 mm)and reread Joël Boutreux service manual. Last page, penultimate paragraph in french: "Longueur idéale pour la TD125 est de 260 mm (Plier en deux)". Translation: the ideal lenght for the TD125 belt is 260 mm (folded in half).

I'll return the belt to Origin Live and exchange it for one of the proper lenght.

Bert
Aha! Thank you for reporting this Bert. I already feared this, 560mm seemed to be way too long (I also read the overhaul manual by Joel).

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Re: Origine Live upgrade belt for Thorens

Post by ehtoo » 06 Dec 2015 22:12

My belt continues to please. As mentioned before, I've installed the OL belt on my TD160B with stock motor. The table is connected to a Music Hall Speed Controller 2.0 with the Thorens speed setting at 45 RPM. When I followed the suggestions by putting talcum powder on the belt, it tended to slip off the spindle. I washed off the talc with some water and problem solved.

At least on the TD160 there have not been any problems. In fact fidelity of the TT has improved with quieter backgrounds and a little more air around instruments. Bass is less bloated. I've gone back to the two other belts I have - a OS Thorens (can't call it NOS as was used for 6 mos) and another after market belt to compare them against the OL. The OL belt was significantly better. What has surprised me more than anything else, is that a belt can make a difference.

Quit frankly, I don't care if it measures a little longer if the results are this good. Most belts for the Thorens are too short which can cause a lot of problems with the motor spindle and added noise. Joel alerted everyone to that fact. I've found myself stretching every belt I've used.

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Re: Origine Live upgrade belt for Thorens

Post by sec4aa » 07 Dec 2015 02:41

I just don't see how a 560mm belt would work for a TD125, but I can work with a 538mm...at least from a geometrical point of view. Thorens belts are a bit short at 520mm and after the now "normal stretching" they can go up to around 530mm after months of usage. I can see how a 538mm OL belt might fit the bill without any stretching required, but they must be a bit stiffer than the elastic rubber Thorens belts. At this length, you need all the grip you can get; no talcum powder should be required. I think that a 520mm OL belt might tension the spindle and the bearing too much...I have a problem if the OL belts are not working well ensuring the 33.3 rpm and I have a question about the MHCC 2.0...how big is the adjustment range? +/-0.3rpm? More? Less?