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Ever so slight platter wobble

I have a bix DIY table that I got from a friend. I noticed that when I look at the bottom of the platter or actually put a solid object underneath the edge of a spinning platter, every revolution the platter will touch the object. You can hear it. The wobble is tiny less than 1/2 mm at the edge. I dont have an arm for this table yet so I do not know how it sounds and I am wondering if I should even keep it. Will 1/2 mm impact sonic performance. Scientifically speaking it should not, right? Since whenever the platter dips, so will the tonearm. Do non diy or high end turntables also have tiny amounts of wobble?
malammik
zargon's avatar
zargon
453 posts
 
What is the platter made of? The fact that the bottom of the platter is uneven may be fine as long as the top runs true (especially if the platter is massive and thick.

The fact that the bearing has play is more serious. Have you looked underneath to see how the bearing is mounted? You might be able to secure it.
malammik OP
10 posts
 
The bearing itself is mounted straight and secure - I've mounted it myself. Platter is made out of glass acrylic. The distance between the platter hole wall and the outer edge of the bearing is not even. At the bottom it is tight and there is no play, but at the top if I push with my finger slightly on a platter you can see through the platter the top portion of the hole becomes "more" in contact with bearing so there is side to side play.
ptmconsulting
1,000 posts
 
Try unseating the platter from the spindle, turning it about 1/4 turn and reseating it. You may have to do this more than once to get it level and straight. Sometimes the machining is just a wee bit off, but you can usually find a spot where everything fits cleanly and straight.

Enjoy,
Bob
malammik OP
10 posts
 
Thanks Bob. I will try that.
dougdeacon
3,338 posts
 
This may sound idiotic, but are you sure you don't have the platter installed upside-down?

A slightly tapered bearing spindle matched to a slightly tapered hole in the platter (both narrower at the top) would provide an inherently stable fit, assuming good machining of course.

And/or what Bob said...
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