3 rolls type plate bending machine designed to be used for the same sector that the 4 rolls type machines are used. There are some differences between the basic design but working principles is same. The most important difference here is the ebsence of 4th roll (center roll) in 3R HS models. The absence of the center roll cause longer flat end comparing 4 rolls type machines.
3 HS, 4 HS model is similar in nature. Top roll has reducer and torque motor. And side rollers are free to rotate along with the material. Centralized lubrication system is optional. Piston movements are orbital (banana) type as in 4R HS model machies. 3HS model shafts is extended so you can use these shaft to bend profile sections with special rolls. This can be excepted as and advantage comparing 4 rolls type.