Hi i have a RD11 Superieour which is undergoing refurbishing. However as far as the platter is concerned this is, unusually, a one piece job i.e there is no inner platter like a Linn or the earlier RD11,s and 80,s.
It comes complete with bearing shaft pressed in. I suppose the RD90 Super. must be similar. Making one is not really an option. I paid about £65 for mine but it came with no power supply and a duff Papst motor.
I have found a power supply and have repaired the motor which now works fine. All i need to do is fit one of my arms. I have a Syrinx PU2 and a PU3 but both need some work as yet. The other problem is arm mounts. Mine is SME so i could fit the PU2 as i have a SME plate for it.
Ahh problems, problems. Its a fine deck though and well worth trying to fix.