I kind of like the idea of a retractable soft top like that of a 60's British sports car. The kind that folds down or unfolds up for when it rains, or gets cold. Only problem is that no one seems to be offering such a thing. And the luxury model would be a powered convertible top, push button operated. Oh boy.
-Steve
The noise from the steppulley comes from the steppulley bearing its oscillating on a frequence at about 440-450Hz and 1600-1700 hz ,the pictures show the oscillating measure without idlerwheel .
Almost every TD124 has this problem its amplitude depends on the state off the bearing .
Volken
View attachment Steppulley oscillation Thorens TD124 span 800Hz.bmp View attachment Speppulley oscillation TD124 span 6.4khz.bmp
Interesting, thanks for sharing. Both my tables have 2 bearings in the chassis as opposed to the earlier single bearing in the stepped pulley. Do you know how the two bearing configurations compare noise wise? It was my impression listening to drive train noise in various tables that the single bearing in pulley configuration was actually a bit quieter if the bearing was good. I've no idea whether or not that is even possible let alone true..
eddy brake and internal step pulley dimensions
speculation:
the interior dimensions of the step pulley must be designed to have:
1) clearance for the eddy current parts
2) for optimal effect of eddy current parts
And the material of the stepped pulley must be magnetically permeable for the eddy brake to have its effect.
We notice/assume that increased eddy current 'intensities' result in a noisier step pulley operation. It might be interesting to test this assumption.
The interior dimension of the stepped pulley results in a bell shape which will produce noise as a result from exterior forces. Like a belt gripping/releasing at velocities consistent with motor rpm. (1400 rpm). Therefore it must ring like a bell.
-Steve
speculation:
the interior dimensions of the step pulley must be designed to have:
1) clearance for the eddy current parts
2) for optimal effect of eddy current parts
And the material of the stepped pulley must be magnetically permeable for the eddy brake to have its effect.
We notice/assume that increased eddy current 'intensities' result in a noisier step pulley operation. It might be interesting to test this assumption.
The interior dimension of the stepped pulley results in a bell shape which will produce noise as a result from exterior forces. Like a belt gripping/releasing at velocities consistent with motor rpm. (1400 rpm). Therefore it must ring like a bell.
-Steve
Which it does very effectively.. 
The best solution I have found so far is to just keep the running surfaces scrupulously clean. Somewhat lower motor voltage helps too, but ultimately where it becomes most effective noise wise (eddy brake magnet backed off a couple of mm, and speed well centered) it seems to kill the dynamics.
The best solution I have found so far is to just keep the running surfaces scrupulously clean. Somewhat lower motor voltage helps too, but ultimately where it becomes most effective noise wise (eddy brake magnet backed off a couple of mm, and speed well centered) it seems to kill the dynamics.
on the subject of E50 motor coils
Backing up to the previous page and discussion about Simone Lucchetti and his motor coil upgrades. So far he has yet to answer my emails. I've sent two.
But his notes about motor coils do bring up some throught provoking ideas. Speed fluctuation of the E50 throughout the day. Even when all bearing/bushing, thrust points maintenance items are optimized. Even if mains voltage doesn't fluctuate more than a few volts.
When I note "speed fluctuation", I mean just a small amount of slow speed variation as seen on the strobe window. Just a little.
Is this due to over-heating motor coils? No question, in my exp. the warmest part of the motor is felt when touching the iron cores holding the coils. Every other part of the motor is cooler. It must be the coils that are heating this motor. When they get to a certain temperature, does this have an effect on motor rpm?
Assuming all answers to above queries are "yes", then the solution must be to do what Simone is doing; come up with a set of coils that do the appropriate task without creating so much heat.
So how hard would it be to wind another set of coils with new magnet wire, and in such a way as to result in cooler operation?
-Steve
Backing up to the previous page and discussion about Simone Lucchetti and his motor coil upgrades. So far he has yet to answer my emails. I've sent two.
But his notes about motor coils do bring up some throught provoking ideas. Speed fluctuation of the E50 throughout the day. Even when all bearing/bushing, thrust points maintenance items are optimized. Even if mains voltage doesn't fluctuate more than a few volts.
When I note "speed fluctuation", I mean just a small amount of slow speed variation as seen on the strobe window. Just a little.
Is this due to over-heating motor coils? No question, in my exp. the warmest part of the motor is felt when touching the iron cores holding the coils. Every other part of the motor is cooler. It must be the coils that are heating this motor. When they get to a certain temperature, does this have an effect on motor rpm?
Assuming all answers to above queries are "yes", then the solution must be to do what Simone is doing; come up with a set of coils that do the appropriate task without creating so much heat.
So how hard would it be to wind another set of coils with new magnet wire, and in such a way as to result in cooler operation?
-Steve
Volken:
[QUOTEThe noise from the steppulley comes from the steppulley bearing its oscillating on a frequence at about 440-450Hz and 1600-1700 hz ,the pictures show the oscillating measure without idlerwheel .
Almost every TD124 has this problem its amplitude depends on the state off the bearing .
][/QUOTE]
I checked my pulley by tapping my finger against it and it rings like a bell. I checked by ear and it is exactly the same tone comming from the pulley when it is driven by the belt (The tone to my ears are between b/c, when i compare it to my piano (around 500 Hz), which is slightly higher than Volken's measurement!)
Is there anyone who has tried to dampen the stepped pulley? There could be several possiblities:
-Electrical tape on the inside of the pulley
-Damping sheet of rubber ashpalt
-Piece of mdf made to fit inside the pulley
Like to hear your thought on this!
Best regards
Nils
[QUOTEThe noise from the steppulley comes from the steppulley bearing its oscillating on a frequence at about 440-450Hz and 1600-1700 hz ,the pictures show the oscillating measure without idlerwheel .
Almost every TD124 has this problem its amplitude depends on the state off the bearing .
][/QUOTE]
I checked my pulley by tapping my finger against it and it rings like a bell. I checked by ear and it is exactly the same tone comming from the pulley when it is driven by the belt (The tone to my ears are between b/c, when i compare it to my piano (around 500 Hz), which is slightly higher than Volken's measurement!)
Is there anyone who has tried to dampen the stepped pulley? There could be several possiblities:
-Electrical tape on the inside of the pulley
-Damping sheet of rubber ashpalt
-Piece of mdf made to fit inside the pulley
Like to hear your thought on this!
Best regards
Nils
I checked my pulley by tapping my finger against it and it rings like a bell. I checked by ear and it is exactly the same tone comming from the pulley when it is driven by the belt (The tone to my ears are between b/c, when i compare it to my piano (around 500 Hz), which is slightly higher than Volken's measurement!)
Is there anyone who has tried to dampen the stepped pulley? There could be several possiblities:
-Electrical tape on the inside of the pulley
-Damping sheet of rubber ashpalt
-Piece of mdf made to fit inside the pulley
Like to hear your thought on this!
Best regards
Nils[/QUOTE]
I also thought dampening. I also noticed the MKI is solid, whereas the MKII has two holes in it. If more holes were drilled, one possibly diminish the ringing.
thank you for the kind words you have for my work. I love the thorens 124, and with new technology it is possible to make a turntable perfetto.non usually write on forums because I think they are the people to talk to me. I love the 124 so much that I made a turntable which is an evolution of the 124. thanks to all and good music . best regards simone lucchetti
I also thought dampening. I also noticed the MKI is solid, whereas the MKII has two holes in it. If more holes were drilled, one possibly diminish the ringing.[/QUOTE]
Well here's a crazy idea. If, indeed, there's nothing preventing one from damping the stepped pulley by filling the inside, then one might consider spray-foaming it, best to use the DOW product intended for windows & doors as it dries with a little spring to it You'd have to shave it once dry, but that's easily done with a serrated knife. The up-side is the stuff is very, very light and pretty sure you'd get even weight distribution. Down-side is if you don't like it, you'll have great fun removing it all! Not to mention you can't get it on any critical surface or your hands because it's sticky stuff! Like I said, perhaps a crazy idea, but figured I'd toss it out there anyway.
Sounds safer, more controllable than my crazy idea. I blame drywall mud dust. Really would rather be working with cork right now.
Damping Stepped Pulley
The story is a bit complicated by the fact that I have three stepped pulleys that differ significantly in small details, but all are intended for later bearing in chassis configuration.
Like the motors I have a fairly early pulley (no holes) and mid 45K SN pulley which has holes but has the spun look on the inside - we'll call this the MKI late pulley, and finally the one in my MKII which is coated internally along one periphery and is significantly lighter than the others - we'll call this the MKII pulley.
I cut some self-adhesive cork for the MKII pulley and put it on the inside (see photo attached) and was astonished to hear that the ringing and other obnoxious noises are completely suppressed - this was sometimes the noisiest of my two tables by a small margin. (Depends on how clean things are) There is some remaining noise which is from the idler.. So this seems like a major step forward..
But remember I mentioned the MKI pulley, did the same treatment if very slightly smaller cork disk. I had trouble getting it to adhere to the spun finish on the inside of this pulley - it may yet fall off. Strangely enough this one did not quiet down with the addition of the cork, however the complex tones emanating from it now sound more like a slow running two pole motor without the masking high frequency content previously present.
Something to mention is I made the piece big enough on the first one to completely block the two holes, the second one is slightly smaller and only covers half the hole. I will revisit this Sunday hopefully.
No measurements unfortunately, perhaps Volken can replicate this.. Note that this does not seem necessarily universal in application.. I have not decided yet whether the MKI is actually quieter in operation or not - the character of the noise has changed. I also polished the pulleys on this table after the initial quick listen to the drive train noise.
The MKII is much quieter and is no longer audible from a few feet away. It also seems to take a bit longer to get up to speed initially, but achieves overall speed stability much more quickly. This also seems to be the case with the MKI, and it also locks on speed more quickly. It could just be that my room is slightly warmer now that spring is visiting the area sporadically.
The story is a bit complicated by the fact that I have three stepped pulleys that differ significantly in small details, but all are intended for later bearing in chassis configuration.
Like the motors I have a fairly early pulley (no holes) and mid 45K SN pulley which has holes but has the spun look on the inside - we'll call this the MKI late pulley, and finally the one in my MKII which is coated internally along one periphery and is significantly lighter than the others - we'll call this the MKII pulley.
I cut some self-adhesive cork for the MKII pulley and put it on the inside (see photo attached) and was astonished to hear that the ringing and other obnoxious noises are completely suppressed - this was sometimes the noisiest of my two tables by a small margin. (Depends on how clean things are) There is some remaining noise which is from the idler.. So this seems like a major step forward..
But remember I mentioned the MKI pulley, did the same treatment if very slightly smaller cork disk. I had trouble getting it to adhere to the spun finish on the inside of this pulley - it may yet fall off. Strangely enough this one did not quiet down with the addition of the cork, however the complex tones emanating from it now sound more like a slow running two pole motor without the masking high frequency content previously present.
Something to mention is I made the piece big enough on the first one to completely block the two holes, the second one is slightly smaller and only covers half the hole. I will revisit this Sunday hopefully.
No measurements unfortunately, perhaps Volken can replicate this.. Note that this does not seem necessarily universal in application.. I have not decided yet whether the MKI is actually quieter in operation or not - the character of the noise has changed. I also polished the pulleys on this table after the initial quick listen to the drive train noise.
The MKII is much quieter and is no longer audible from a few feet away. It also seems to take a bit longer to get up to speed initially, but achieves overall speed stability much more quickly. This also seems to be the case with the MKI, and it also locks on speed more quickly. It could just be that my room is slightly warmer now that spring is visiting the area sporadically.
Attachments
I think I am going to try again on the second table, it now sounds a little bit like a tiny washing machine on spin cycle, oddly enough however this table in terms of listening is substantially better than it was.. The other one was already rather further up the food chain, but even there the highs seemed a bit more open. Ah, I hate subjective crap, but there might be something to damping these damned stepped pulleys.. Anyway something for all of us to experiment with..
I cut a slightly larger cork circle for the older pulley as it appears that the holes are further out towards the edge on the older one. No difference, it is still making an odd noise it doesn't without the cork, however what is coming out of the cartridge terminals still seems like an improvement.
No doubt about it actually on the MKI, the improvement is pretty clear mini washing machine or not, the MKII is much subtler as it has always been the rather better performing of the two tables.
No doubt about it actually on the MKI, the improvement is pretty clear mini washing machine or not, the MKII is much subtler as it has always been the rather better performing of the two tables.