I can not keep silence any more on this topic.
Yes,I have to admit that it's an indutrial problem on how to keep a concentric alignment when swapping platters.
SalvationDATA provide one solution on this problem. it is the Head Platter Exchanger pro. There are many clients selected this crazy tool because it really works on most hard disk. Except the 300GB, 500GB Seagate hard drives and Samsung 250 GB hard drive as there are dividers between the platters.
As wawalab said, he can use adhesive tape wrap Platters' brink and take them out perpendicularity. It sounds more crazy.

To hybris2k:
IMHO, you can use our crazy tools or your skillfuls hands to swap multi-platters. I want to say, no tool can solve all your problems in the world. So far there is not a push-botton solution for physical DATA recovery.
We, gurus here and SalvationDATA staff, are keeping searching for the best way to solve the problem that we already encountered and will encounter .
Best wishes
Laura Lee
_________________
SalvationDATA--Profesionnal Hard drive solution Provider. MSN:
sales.laura@salvationdata.com