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?
Platter swim is undesireable in that it will cause the arm to go up and down, putting undue stress on the cantilever and stylus, as well as affecting the pitch of sounds. I am not familiar with your turntable, but some of this may be a setup error. Put your platter on an absolutely flat surface, and see if the platter is true, or not. If it is, look at how the female part of the bearing is affixed to the plinth and see if there is any looseness. Finally gently rock the spindle to see if there is any play in the main bearing.
There is play between the bearing and the platter if I press if my fingers very slightly onto the edge.
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.
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.
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.

Thanks Bob. I will try that.
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...
This does not sound idiotic at all. I do not know much about this table so I am not even sure which side is top and which is bottom and I tried it both ways. I will wait to get home tonight and try Bob's suggestion of various positions to see of there is one that reduces or eliminates wobble.
Here is a video of the wobble http://vimeo.com/8338593
This is a common problem, that usually occurs when the user plays too many records consisting of Rock and Roll :).
Were you working the camera in the Blair Witch Project? I actually threw up a bit in my mouth a bit watching that....

Anyway, is it sandwiched?, like the top of the spindle and the underside thread together to clamp the platter? or through and just resting the platter like the Regas. If so is it tightend right down? If so, and there's still some play maybe it's missing a washer, and perhaps putting a thin washer in under the platter will snug and flatten it. Not so much a washer but just a flesbible rubber diaphram, you might get one to fit in a plumbing section or just fashion it from some thin rubber/vinyl sheet. Haven't seen this one before but just a thought....


Hey. The wobble video is wobbly. The table was on a floor and I did not have good support. Thanks for the advice. I will try that out. The platter is not sandwiched.
So, then does the spindle wobble in it's seating with the platter off? ie can you shift it even slightly from side to side with the platter removed but the spindle's in place?
ie not 'flesbible' but flexible,ar ar.
I'd be careful about any kind of washer, since that would intruduce an interface between platter and spindle that is not a firm and tight connection and can affect your sonics.

Try moving the platter about the spindle and see how that works. I had the same problem on my old VPI and this is what they suggested to fix the issue, which it did. Make sure it is pressed down firmly after seating. On the VPI this was done by cranking down the threaded record clamp, but I don't know what that means on your table and if it has a record clamp that is threaded or not.

Good luck,
I watched the video. My observations are: The contact area is very small and close to the center of the supported mass. A larger diameter should have been used to support the 12" platter. It's just a bad design, coupled with poor execution or machining. You ultimately get what you pay for, Chinese manufacturing quality is a crapshoot.
I own a Teres table with wooden platter. Over the years, the platter developed a minor wobble attributable to shifting or shrinkage of the wood itself. I've spoken to Chris Brady about this, and we both agree that its sonically insignificant if less than 2 or 3 mm.
"You ultimately get what you pay for, Chinese manufacturing quality is a crapshoot." would that be the same chinese manufacturing as the a fore mentioned VPI and Teres?
It is a crapshoot but not necessarily always on a bad side. I have Antique Sound Labs amps made in China. Build quality and sound quality are very good.