I have an old Sorvall centrifuge, and just had a heck of a time getting
the GSA rotor off after it got stuck on the spindle. I balked at buying
the rotor extractor tool from Kendro (couldn't get it in time anyhow) as
it was $150. After trying various things for several hours, I
discovered a method that worked and should work in the future. Of course
you do it at your own risk, but I think it is fairly gentle (probably
more gentle that wiggling and pulling the rotor).
1. Remove the lid
2. Carefully place three or four nuts 1/2" diameter nuts in the hole (a
hemostat was good for this).
3. Replace the top and tighten down using the larger (outer) knob
(don't tighten the inner knob as this attaches to the spindle). Be
careful not to cross thread. The rotor should pull off just as if you
were using the $150 tool.
I actually had removed the retaining clip inside the lid and removed
the large screwdown knob, but after discovering this method, I was able
to do it without removing the knob from the lid.
Thought I would post this here so people could search on it in the future.