Quoted from shaub:

Stern has posted the manual for the Prem/LE now, so I went to see what the differences were between the Pro disc motor/assembly and the Premium disc motor/assembly, but they appear to be identical. I wonder if there is any practical reason the Pro only spins one way, or maybe there is something I'm missing.

Quoted from gumnut01:

I did and reset the pizza motor and reset the machine. No change thanks.
I have also had prodoshi confirm this happens. The shaker motor pulses with the pizza motor starting and stopping
BTW, if you have an LE what does your shaker do when the pizza starts and stops?

Quoted from gumnut01:

But it happens for no reason. And the pizza stops on a timer so then you have a hurry up shake on the machine and nothing is happening. Most of the time I’m just cradling the ball or setting up my next shot and then the machine rumbles because the pizza stops spinning. It’s off putting. It’s a useless distraction. Until I knew what was causing it I thought “the pins trying to tell me to shoot for something .... what?”.
And then I thought “my shaker is malfunctioning, it’s shaking for no reason”.
Shaker should be used for achievements Like 123 foot or weapon completions (which it is not). Not for mechanisms just winding down. The pizza spins for a multitude of reasons, usually missing the left ramp since it starts up for hitting one of the targets on the sides of the ramp. So it hardly needs any fanfare.