(ok.... jumping in with my $0.02...)
more choices is always good !!!....
but we already have quite a few choices in spinners....
(and frankly... their qualities are good !!...)
if you want to do a small batch of spinners and compete with cheaper prices.... yes, I think it'll be ok... but cheap price alone won't manage in the long run.... quality product rules in the long run....
if you really want to sell.... think about steering wheels !!!!
there're currently no such thing out there !!!...
I think I have seen an Arknoid spinner before....
the spinner itself deosn't share the axis with the encoder... but through 1 or 2 gears....
to support the wheel.... you'll need 2 bearings (like the Tornado)..... and a thicker axis.... then 1 gear and that connects to the encoder wheel...
and on top... maybe a screw and nut top so that you can mount any gneric steering wheel.....
and I think this WILL SELL !!!.....
but I really... really don't have the time for it.....
nor the skill set to make this happen....
(still cutting pieces for my cab....)
hopefully.... I'll be able to finish before winter comes...
(then it'll be too cold to work in the garage....)