SkyStopper uses threaded shaft couplers
The SkyStopper uses aluminum shaft couplers which are threaded on one side to accept the 5/16-24 thread of the shaft they turn.
Threading the shaft couplers reduces the complexity of the device and eliminates the need to grind the shaft round
at the ends.
Standard size Roller Blade bearings are used.
Where the shaft goes through the bearing, there is a small amount of clearance.
This clearance is taken up by a single layer of thick adhesive tape wound around the shaft.
(The handyman's secret weapon)
The plastic tape centers the shaft in the bearing.