Daz,
I use the L7S for my Tyros2, but I've found another solution for the 3K. It's sold under a couple different names (Adams AKS1175 and Onstage KS7100) They're built solid and won't wobble. They're fully adjustable and they fold up easily.
They're available at these sites:
ZZSounds
and
Fermata
I'm getting ready to order a second one for my wifes 88 key piano keyboard. Price is about $50 bucks.
Good luck and make music.
Ron