Nottingham spacedeck motor - driving me crazy

45 RPM is harder for the motor to pull than 33 1/3, like trying to get your car moving in 2nd gear instead of first. If it will work at 45, the problem is not the motor.

I suspect that the reason the belt doesn't slip at 45RPM is because the 45RPM pulley has a larger diameter than the 33RPM pulley. Since the grooves for both speeds on the Spacedeck's platter are the same diameter, the belt must stretch to accomodate the bigger pulley. That stretch probably means that the belt is pulling "harder" on the 45RPM pulley than on the smaller one. The distance between the motor and platter seems to be critical. I have a PDF copy of the NA dealer manual and it calls for 6mm between the two pieces.

One other thing to check: due to its weight, the motor sometimes will slip down in its pod over time. When that happens, the grooves on the pulley no longer line up with the grooves on the platter.

Good point, John. I'd forgotten about that NA motor quirk. Here's what the dealer manual says about the motor height: "The motor height is adjustable and it is important to line up the grooves on the pulley with the grooves on the platter. Make sure the table is leveled first. If you need to raise or lower the motor, do so by pushing on the motor itself. It is snug in its housing, but it will move."

You shouldn't need to loosen the screws holding the motor to the housing to do this.

That was an occasion when my Spacedeck motor spins at varying speeds and at times it does not stop at all. That was real insanity then.

I replaced the motor and from then on, I never leave the motor on. If you touch the motor, you will notice that it does gets warm in its standby state.