A stupid Happ Supers question

[Fstuff]

I KNOW this is stupid but I still need to know. Just bought some Happ Supers and without being too technical the black flat spherical thing (help me out here..) confuses me. It's been a long time since I played on an arcade cab (hence the project) but I could swear the part in question never moved on those. But the only way I see too fit it is to make the holes in the panel big enough for joystick rotation and not attaching the 'thingy' to anything, meaning it'd move with the joystick. Is this right or what? For I can see no other way..

Jesus Christ I need some sleep, it will all be clear in the morning it will all be clear in the morning.. it WILL.. some..how..

[Ambrocade]

Well, it's been a while since I have played a true arcade machine but I used to have a Hotrod and now I have an ArcadePC that both use Happ Supers and the black flat disc moves on both panels.  I have since made my own panel for the ArcadePC and the disc moves slightly when using the sticks.

I think the flat disc basically just covers the hole where the stick goes through the panel.  If the disc didn't move that means the joystick couldn't move either...

[Fstuff]

Yeah, that's what I figured. It's not a problem or anything, I just needed to know if I wasn't missing something really obvious. Danke schon!