spindle bearing

[bob38138]

I have seen turntables with a bearing ball pressd on the spindle riding on a delrin or teflon thrust plate.

Anyone have any experience using a second bearing ball in place of derlin or teflon thrust plate?

thanks!
bob

[AudioOrigami]

you may find the teflon helps damp the bearing...might help stop bearing noise

might be worth a go tho
altough watch out for:

useing a ball bearing might lift the hieght of the platter if its thicker than the origonal teflon plate....

and finally the 2 ballbearings might have a tendancy to want to wobble if the 2 centers are not exactly kept true

best wishes
j7

[kilowattski]

AudioOrigami,

I could have sworn I saw on your website somewhere that you were working on a turntable main bearing. Was I just dreaming or is it true? If it is true how is it coming?

[AudioOrigami]

Originally posted by kilowattski
AudioOrigami,

I could have sworn I saw on your website somewhere that you were working on a turntable main bearing. Was I just dreaming or is it true? If it is true how is it coming?

hi
its on my web site www.audioorigami.co.uk ...in the floppy project ...part 3
there is a thread in here on DIY as well

best wishes
j7

[InDaGroove]

If the platter is heavy, you're talking about humongous PSI. For my 30 lb. platter, the PSI was over 4 million! I was considering two ceramic balls- they would have shattered or ground each other flat. I'm using ceramic ball/delrin plate now and it is fine. The divot made in the plastic is very small.

Wobble is also a real concern, as already mentioned.

Colby

[multi-volti]

Back in the mid-80's when I was turntable shopping, the Linn LP-12 folks harped about any lack of rigidity causing loss of small details.

The LP-12 bearing is machined onto the end of the spindle and rides on a metal thrust plate...no play between the end of a spindle and a bearing. They claimed it was one of the most important design issues in the LP-12 design.

I think the lower-priced Axis did something different but I can't remember what.

Anyway, I don't see the benefit of two moving parts under the platter spindle. If the pressure is as great as a previous poster calculated, what might have seemed to be trivial, miniscule or dismissable issues may contribute to 'problems', audible or otherwise.

Sphericity of a bearing can only be 'so good'. Who knows what happens when you put two together and they randomly interact as they rotate under high pressure?

I see two reasons so far to keep it simple...I'd stick with one bearing at most.

Murray

[bob38138]

Thank you for all of the replies.

I knew that the Yorke turntable used a 2 bearing set-up, with no abnormal wear issues and it produces world class sound.

I know that there are a number of grades of finish on ball bearings and assuming everything was machined correctly, a high grade ball bearing set-up would produce less friction than a set-up with a single ball and a teflon-type thrust bearing.

I may prototype a daul ball bearing set up and report back to the forum....

[AudioOrigami]

coolness

[Vinyl-Addict]

Originally posted by bob38138
Thank you for all of the replies.

I knew that the Yorke turntable used a 2 bearing set-up, with no abnormal wear issues and it produces world class sound.

I know that there are a number of grades of finish on ball bearings and assuming everything was machined correctly, a high grade ball bearing set-up would produce less friction than a set-up with a single ball and a teflon-type thrust bearing.

I may prototype a daul ball bearing set up and report back to the forum....

I was asked to rework a York platter several years ago. The owner dropped it on the ground and dented it so I turned it on the lathe to freshen it up, just the corner needed fixing.
I do not remember seeing a dual ball bearing setup though.

I don't see how it could be a good thing since the bearing axle alone rotates. The ball bearing is fixed and does not turn. THe thrust plate is simply there to dampen energy and support the bearing ball. Introducing another ball would only make things more complicated than they need to be, IMO. AudioOrigami already stated the eccentricity issue to think about.