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Old 2nd April 2014, 08:02 PM   #1001
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Originally Posted by jswen View Post
I live on a farm with a dusty road and house dogs. I have an old Dual dustcover that would sort of work, but agree with Steve as to where to put it when the TT is in use. Has anyone tried a light cloth like the Stanton CTC-1 Cloth Turntable Cover or any other thoughts? I like the brush idea.

I suppose I could vacuum more, but then I can't hear the music.
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.

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Old 2nd April 2014, 08:10 PM   #1002
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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
Funny! I used to own Triumphs with ragtops. You need the top to a baby carriage.
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Old 3rd April 2014, 12:09 AM   #1003
kevinkr is offline kevinkr  United States
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Perhaps you could make some with acrylic sheets or other appropriate material. Online metals amongst others sells material cut to custom sizes.
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Old 3rd April 2014, 12:18 AM   #1004
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I think I'll go the cloth route. Chiffon appears affordable and light weight.
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Old 3rd April 2014, 04:29 PM   #1005
volken is offline volken  Netherlands
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Originally Posted by Rjones5296 View Post
Guys
I have been thinking, with the 124 the first steps are getting the motor and bushings in order, once this has been done the table is quiet. What I have found is after all this, The majority of noise is caused by the effect of the eddy current brake. lessening this effect = less noise. My tables are very quiet, at this time I have to use a stethoscope to hear this effect.
What im considering is reducing the size of the motor pulley a few thousanths of an inch, reducing the speed, allowing for less brake effect & noise.
Thoughts ?
bob
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

Steppulley oscillation Thorens TD124 span 800Hz.bmpSpeppulley oscillation TD124 span 6.4khz.bmp
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Old 3rd April 2014, 05:43 PM   #1006
kevinkr is offline kevinkr  United States
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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..
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Old 3rd April 2014, 06:03 PM   #1007
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Default 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
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Old 3rd April 2014, 06:14 PM   #1008
kevinkr is offline kevinkr  United States
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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.
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Old 3rd April 2014, 06:29 PM   #1009
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Default 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
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Old 3rd April 2014, 06:55 PM   #1010
nilsW is offline nilsW  Sweden
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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
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