does anyone make Ho scale rotary couplers???????? - Trains
709 posts. Posted by nedthomas on Monday, August 1, 2005 8:29 PM. Dumping cars with rotary couplers requires a larger dumper and more horsepower to turn the cars. Without rotary couplers the dumper turns the car on the car center-of-gravity which for a loaded car is higher than the coupler centerline.