Bad standards are better than no standards

[Aengus]

Not always true, I grant; but if there are standard dimensions (etc.) for an item, it's good to adhere to them unless there's a reason to deviate.

So, are there standard turntable dimensions? I have searched, both in the forum and on Google, for things like "turntable standards" and "RIAA turntable", etc., and got a lot of irrelevant things back. Surely someone, at some time, said that TTs should have a certain diameter, that spindles should be of a certain size +/- x, etc. - or at least said this of LPs, which would come to the same thing in the end.

My Linn has a platter diameter of 11 3/4" (298.5mm); and a spindle diameter of ~9/32" (7.26mm). Should I take these as normal dimensions? Is there some other critical measurement that should be standard as well?

Any help welcomed, including search phrases I didn't think of, and pointers to threads that I was too thick to find

Regards.

Aengus

[Phileas Fogg]

Most record platters are in or around 12 inches or 30cm in dia. Spindles tend to be about 7mm. in Dia. After that all other standards are set for each arm, or the ratio of gearing for motor pully to platter drive (sub- platter drive ) on belt drives etc. TT's usually have the most eccentric outer dimensions, set usually around designer's specs or ideas but if you want to have a table resemble close to the size of other gear 17inches wide by about 12 or 13 inches deep for a plinth is a good starting point.

[vinylkid58]

Aengus,

Other than the platter dia. and spindle dia. (probably the most important), is there another area that you feel should have a particular standard set of measurements etc?

Jeff

[Aengus]

vinylkid said:

Other than the platter dia. and spindle dia. (probably the most important), is there another area that you feel should have a particular standard set of measurements etc?

No, in fact I can't think of any others that would even be candidates; but - as I have had demonstrated all too often - me not being able to think of something doesn't mean it wasn't important

Phileas's note about the possible desirability of conforming to norm for plinths is a case in point - fitting on a standard shelf is probably a good thing, all else being equal (though it never is, of course).

I've occasionally had LPs that were a very tight fit on the Linn spindle, though most fit just fine, and I suppose that the occasional tight fit is better than a frequent sloppy fit. Just wondered what (if any) the standards are for this.



Regards.

Aengus

[vinylkid58]

I've occasionally had LPs that were a very tight fit on the Linn spindle, though most fit just fine, and I suppose that the occasional tight fit is better than a frequent sloppy fit. Just wondered what (if any) the standards are for this.

I measured the spindle on a friend's Rega P3 (older) and it was about .005" bigger than my Linn. At the time he was designing a record clamp, so there was some variation in spindle diameters to be considered.

Jeff

[Phileas Fogg]

Yes, spindles are not 100% universal. My DIY spindle was made for me to a 7mm size or roughly 5/16ths inch. I have had no issues with LP's fitting on my spindle.

[jeff spall]

Hi guys, there are RIAA standards for all the record dimensions like diameter and where the audio should start and end.

Because they are pretty old and American, the standards are in inches.
An LP works out at 302mm but there's no standard for platter diameter, so would an edge to the flat part of the platter at maybe 295mm give a little overhang to lift the disc off with?

The record hole is specced at 0.285 inches for a spindle of 9/32 (0.2812) and this goes way back to the dawn of the 78.
With a tolerance of +-001 for both, there should never have been a case where the record would actually not go on!
Dunno about your metric conversion - my Mitutyo Mic converts that to 7.144mm (?)


regards, Jeff

[Aengus]

Jeff Spall said:

The record hole is specced at 0.285 inches for a spindle of 9/32...tolerance of +-001

Thanks, Jeff - just what I was looking for. Sounds like a spindle of .280 (.2812 - .001) would be about right.

Vinylkid58, do you still have the dimension of the Rega spindle?

Regards,

Aengus

[vinylkid58]

Originally posted by Aengus

Vinylkid58, do you still have the dimension of the Rega spindle?

No, but I can find out for you.

Jeff

[Aengus]

Thanks, Jeff - if it's convenient. Otherwise, don't worry about it.

Regards.

Aengus