I got one of these several months back and have been having a blast with it.
I wanted to pass on something I found out and since all the old topics have been locked, I thought I'd start a new one.
I recall folks having issues with the TT stalling periodically and I had the same problem. Mine seemed to be stalling only in certain locations, but not every time.
I'm using a variable/selectable DC voltage wall-wart to power mine and had it set on 9vdc. I turned it down to 7.5vdc and so far have not had any stalling occur at that speed. I read the instructions but I never saw if there was a maximum voltage recommended (other than max for the 12vdc motor).
I can also run it at 6vdc, but it's fairly slow even at 7.5vdc and works fine at that speed.
If any of you are having problems try reducing the voltage to the motor and see if that solves the issue.
Next step for me is to weather the TT.