Here is another exercise machine that helps you work on your hip and core muscles. The Ya-Man Twist Ride 3D Exerciser has 3 modes for you to choose from. It has an anti-slip seat for a safe workout. The Ya-Man Twist Ride Exerciser can handle users up to 176lbs.
This trainer weighs only 12.3lbs, so you can easily take it with you anywhere. More info is available here.