Just an idea on how to put the potentiometer on the hi hat stand
the first part you need is this thing (I don't know his name in english)
The second part is this plastic piece
The third is a pot
1st step
cut the plastic piece
like this
2nd step
mount the potentiometer on this plastic piece and glue it
3rd step
mount the first pièce (picture one) on the hihat stand and introduce the potentiometer on the hole of this piece
a close up
That's all
Later I will connect the Jack like this
I'm sorry for my bad english