MTH Programmable Protosound 2 station "drift"

A long time ago when this discussion first came up, it was mentioned that the drift is normal and just a limitation of the repeatability of the system.  That tach reader on the flywheel is really good at taking a measurement of how many ticks go by to keep the set speed pretty constant, but when its used it to do the station stops it will eventually do exactly as you describe.

There may have been a thread where a person was trying to set up an unattended display in a store of some sort, and I think the end result was that this feature was not really capable of the long duration unattended operation that person was looking for.

How fast this happens (like after how many cycles) probably depends on the length of the run for your cycle, maybe other factors too.

It's not in the manual, that is for sure.  MTH was not in the habit of describing little feature limitations like this in their documentation.

-Dave

The logic is fairly simple, wheels slip at times, especially on curves.  They never seem to slip the exact same amount, so there is a certain amount of "creep" in the exact stop, even if the tach pulses were counted accurately.