Much talk about the drones failing in this thread. There are two possible reasons why, in my view as a life long RC hobbyist, they're failing with such frequency:
1) The drone motors are "coreless" DC motors that contain very small permanent magnets inside. I think the 5 industrial strength magnets in DI, in proximity pulsing on/off constantly might be a major culprit to the efficiency & life of the little drone motors. This might depend on the North-South orientation of the game magnets mounted in the table, and the N-S orientation of the drone motor magnets. *if* these poles happen to be aligned the wrong way, I think its possible the game magnets might actually be acting as demagnetizers to the permanent magnets in the drone motors, which would fail the drone motors.
2) The drone motors are reportedly wired in series inside each drone body. DC motors can be run in series, and in *theory* they'll equally proportion the voltage among themselves but in practice this doesn't work well at all. What will happen is due to variations in each motor's efficiency and the load its running under, in time the motors will develop current draw imbalances leading to imbalances in how voltage drops across each motor in a series circuit. The result is that in time, as the motors change, the circuit goes so far out of balance it results in one or more motors failing to run at all.
In all the years I've flown RC airplanes, heli's and drones (over 40) I've never had a DC motor failure outright (one did catch on fire in flight, but that was my fault for running it on 150% of design voltage with insufficient cooling). Yes, it does happen, but its very unusual. Certainly, these micro drone motors aren't the best in quality but in actual drone use they're amazingly reliable. So I think its related to the pinball installation, not the motors per se.
Sorry I'm not offering a fix here, but just thought I'd add my .02 based on experience as to possible sources of trouble.
Really REALLY looking forward to taking delivery @ TPF! Cheers ...