Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Speed control collar broke after an hour!

I had the same experience as Donna M. Freeth below. Something came loose inside the motor and the motor revolutions increased to frightening speed. I opened the yellow top and discovered 3 pieces of what used to be a black ring. I'm pretty sure it's the variable speed control for the motor because it sits right below the top bearing and in front of the speed control module. So much for buying quality for peace of mind!