Spindle top bearing, is the turntable a gyroscope?

[Daithi]

I have noticed that the spindle top bearing is usually a simple plain bush or even just an unlined hole drilled in the motor frame casting. Why didn't they use roller bearings, needle bearings or ball bearings? Is it because the platter tends to behave like a spinning top and center itself as soon as it gets to a particular speed, and that therefore a more sophisticated bearing is not needed? Or were they just being cheap?

[Lucius1958]

Probably plain economy. Most of the disc motors I have are fairly quiet.

The only one I have had much trouble with is the Talkophone: it takes a lot of adjustment to get it not to sound like a coffee grinder. I have tried to get the slop out of that bearing by various means, with only limited success.

- Bill

[JerryVan]

I have noticed that the spindle top bearing is usually a simple plain bush or even just an unlined hole drilled in the motor frame casting. Why didn't they use roller bearings, needle bearings or ball bearings? Is it because the platter tends to behave like a spinning top and center itself as soon as it gets to a particular speed, and that therefore a more sophisticated bearing is not needed? Or were they just being cheap?

Unless they're high precision bearings, (which are expensive), roller, needle, & ball bearings can actually produce noise. A well lubricated plain bearing will be quiet and last 120 years, (and counting). There is no gyroscopic effect at play here.