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Old 13th June 2007, 08:04 AM   #111
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That is an Amazing TT. Brilliant work.

I would like to build something similar, one day...
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Old 15th June 2007, 01:15 PM   #112
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Congrats, vinyl-addict - outstanding job!
Clever and simple engineering and tasteful aestetical look combined with top-class work - it is rarely seen combination in DIY world.
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Old 15th June 2007, 05:41 PM   #113
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Quote:
Originally posted by jrevillug
That is an Amazing TT. Brilliant work.

I would like to build something similar, one day...

Quote:
Originally posted by livemusic
Congrats, vinyl-addict - outstanding job!
Clever and simple engineering and tasteful aestetical look combined with top-class work - it is rarely seen combination in DIY world.
Thank you both for the kind words.
I am more fortunate than most DIY folks since I have a fully capable machine shop at my disposal along with CAD/CAM software, etc. The DC drive is Mark Kelly's design so many thanks to Mark for offering that to me.
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Old 16th June 2007, 07:52 PM   #114
Nanook is offline Nanook  Canada
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Default Mark Kelly's design.

so a DC voltage controller? I am looking for an AC one, any ideas?
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Old 3rd July 2007, 10:18 PM   #115
Triumph is offline Triumph  Netherlands
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Wish I have read this thread before. As Ynwoan mentioned in his first tread:

Quote:
I have read elsewhere on the forum that the edge of the platter can be seen to rise and fall with some magnetic bearings
My experimenting with two neodymium ring magnets (see picture below) failed because of unbalance of the platter, not because off axial forces but of tangential forces of the magnets. Even after honing the sliding bearing to a minimum tolerance the platter has a “tide” of 3 mm.

It must be possible though, see:
http://images.google.nl/imgres?imgurl=http://www.coolgales.com/store/images/ClearaudioMagneticBearing70.jpg&imgrefurl=http://www.coolgales.com/store/cart.php%3Ftarget%3Dcategory%26category_id%3D44&h= 45&w=70&sz=3&hl=nl&start=7&tbnid=VV_pvs-iHL5s_M:&tbnh=44&tbnw=68&prev=/images%3Fq%3Dclearaudio%2Bmagnetic%26gbv%3D2%26svn um%3D10%26hl%3Dnl%26client%3Dfirefox-a%26channel%3Ds%26rls%3Dorg.mozilla:nlfficial%26 sa%3DG
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Old 3rd July 2007, 10:22 PM   #116
Triumph is offline Triumph  Netherlands
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Sorry,

The Clearaudio magnetic bearing link:

http://www.coolgales.com/store/cart....category_id=44
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Old 3rd July 2007, 10:44 PM   #117
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Judging from your thumbnail image, it looks as if the magnets are way too far apart and the platter is also extended too far as well. I can see how you would obtain poor results if that is an accurate picture of what is going on. My magnetic bearing only deviates 0.1mm and that is most likely due to the acrylic platter's imperfection.

Quote:
Originally posted by Triumph
Wish I have read this thread before. As Ynwoan mentioned in his first tread:



My experimenting with two neodymium ring magnets (see picture below) failed because of unbalance of the platter, not because off axial forces but of tangential forces of the magnets. Even after honing the sliding bearing to a minimum tolerance the platter has a “tide” of 3 mm.

It must be possible though, see:
http://images.google.nl/imgres?imgurl=http://www.coolgales.com/store/images/ClearaudioMagneticBearing70.jpg&imgrefurl=http://www.coolgales.com/store/cart.php%3Ftarget%3Dcategory%26category_id%3D44&h= 45&w=70&sz=3&hl=nl&start=7&tbnid=VV_pvs-iHL5s_M:&tbnh=44&tbnw=68&prev=/images%3Fq%3Dclearaudio%2Bmagnetic%26gbv%3D2%26svn um%3D10%26hl%3Dnl%26client%3Dfirefox-a%26channel%3Ds%26rls%3Dorg.mozilla:nlfficial%26 sa%3DG
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Old 3rd July 2007, 11:55 PM   #118
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loaded with the platter ynoans magnet only floats the platter by a couple of mm. he uses a LINN bearing so the spindle is sleeved all the way up, hence no increase in lateral play.

this solution doesn't work so well with garrard and lenco style bearing as the spindle is quite short, you would need thin magnets of greater circumference so that they sat outside of the platter stub as shown in your image.
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Old 4th July 2007, 05:18 AM   #119
Triumph is offline Triumph  Netherlands
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The picture shows the distance without the weight of the platter. With the platter it is also only a couple of mm.

In a later version a made 3 adjusting screws for leveling the bottom magnet and also a adjusting mechanism for the top magnet but still it couldn’t prevent wobbling of the platter.

Were to order magnets:

http://www.monstermagnete.de/catalog/index.php?cPath=37
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Old 4th July 2007, 01:08 PM   #120
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https://supermagnetman.c3.ixwebhosting.com/login.php


a bit further away but he does stronger magnets and more ring sizes.

the 41mm fits a rega platter perfectly.
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