I run my MDT Plymouth switcher regularly on Kato's CV1 track set, including turnouts, without any problems. According to the CV1's packaging, the curves have a 6 inch radius (150mm). This is part of a mining operation on my layout and I usually run the locomotive with 3 or 4 short ore cars (Atlas). I have not experienced any problems. Since I do not have any track with a smaller radius, I cannot comment on that. Hope this helps.