Magnetic isolation

Fec,

You've peaked my interest.  What magnetic levitation product are you using?   I'd like to read up on it.

Geoff, my statements don´t conflict (maybe a little typo though ?).
Try this: A heavy deck needs strong magnets but not TOO strong. Then gap between deck and feet becomes too long resulting weaker magnetic field and thus more unstable balance. The essence is dense magnetic field between deck and feet, as dense as possible in fact.
2 mm gap gives denser magnetic field. 

The more dense magnetic field results to stronger magnetic force and thus better stability. The magnetic push needs to be just enough. That´s the trick :)

Indeed, a dense magnetic field utilizing magnets that are suitable for the load.
I think the gap I have is about 2 - 3mm. 

That´s good... maybe you could try about 1 mm... ;)

Ha! I'll employ some mass & see if there is any difference...