Platter positioning

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hebridean
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Platter positioning

Post by hebridean » 20 Nov 2019 00:17

Any thoughts on the positioning of the decks platter (td145) onto the belt driven platter. Both have three keyholes in them for I'm assuming casting purposes and have often wondered if their positioning has any importance in relation to each other.

ddarch
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Re: Platter positioning

Post by ddarch » 20 Nov 2019 00:25

No, not really.

There will be occasional platter matches that are more dependent on being in one place versus just placed anywhere. If you don't, there will be dips and rises as the platter rotates. Maybe one in 7 or 8 of the tables I sell, I have to methodically try different positions of the outer platter in relation to the inner platter, searching for the position that results most closely to spinning flat. I do this using a series of sharpie dots on the outer platter matched up with a line on the drive platter. I use a spark plug gauge in three places (1pm, 4pm, 7pm) to assess the gap.

JDJX
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Re: Platter positioning

Post by JDJX » 20 Nov 2019 17:47

Yeah.. just mark the inner and outer platter together when you find the optimum position.

BTW, of course, first make sure that both mating surfaces are clean :)
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hebridean
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Re: Platter positioning

Post by hebridean » 20 Nov 2019 17:59

Many thanks for your replies, very useful advice.

StephDale
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Re: Platter positioning

Post by StephDale » 20 Nov 2019 20:54

I agree with the guys above and do exactly the same. There is one other wriggle; there is often slack between inner and outer platters on these cast ones (the later machined ones generally don't have slack), which you can do the same job using a small strip of paper to take out the slack and improve the eccentricity. Here's a shot of my TD321 platter with both sets of marks and the paper strips on top:
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The paper is just a strip cut from a sticky-note.

Steph

hebridean
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Re: Platter positioning

Post by hebridean » 21 Nov 2019 11:43

Another excellent tip Steph. I'm going to have a look at the two i've got and see if i need to use these.

Bufo Bill
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Re: Platter positioning

Post by Bufo Bill » 08 Dec 2019 15:33

Does the uneven match up cause a problem with sound reproduction? I am presuming yes?
Bill.

StephDale
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Re: Platter positioning

Post by StephDale » 08 Dec 2019 16:35

Bill,

It's probably debatable, certainly the conventional run out check is worth doing as high levels of run out can cause wow, in the same fashion as a warped disc.

The lateral check is more to do with evening up platter weighting, which will have effect on even rotation and bearing noise. Whether any of us would notice the difference is academic...

Steph

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Re: Platter positioning

Post by noisefreq » 08 Dec 2019 16:44

I do the exact thing as above with a pencil rather than a sharpie.

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