Thanks Guys for the replys!

It looks like the 'Do it best' bearing fits the bill quite nicely.

Jim,

the 'Aluminium Lazy Suzan Bearing' look really nice, but I'm afraid, it would increase the spacing a bit too much for the azimuth encoder to work. The spacing required is about 6.25-6.5mm. The Aluminium bearing has a thickness of 12.7mm whereas the 'do it best' bearing has a thickness of 7.9mm, so I guess it fits the bill better.

Any body else with any suggestions/feed back??

Sabir