For the hydraulic pipe bending machine,the encoder is used to control the angle if the encoder control angle itself is not a problem. And it can also ensure stability as well. However, as the bending drive comes from hydraulic cylinder, it works well while the the hydraulic bending is under normal oil temperature conditions. But the bending errors occur when the oil temperature rises after working for a long time. The bending cylinder of the pipe bender is controlled by solenoid valves, so that the working stability is seriously influenced when hydraulic oil becomes thinner due to the high temperature. If the solenoid valve cannot completely lock the control flow, so the angle will be unstable if the pipe will be bent.

Figure 1  Hydraulic tube bender and servo tube bender

The servo pipe bender is using servo motor as the driven power of bending.the stability of the servo motor accuracy is perfect, so the bending angle is very good, and it is not influenced by the rising hydraulic oil after working for a long time. Therefore, if customers’ budget is enough and have high requirements in products precision, BLMA strongly recommend a servo pipe bending machine for achieving best economical efficiency.

Moreover, servo pipe bending machine performs much well in terms of bending speed. According to the data from China CNC Machine Tool Research Institute, servo pipe bending machines are getting more and more market share since 2010, the following diagram will help you comprehend better.

Figure 2 The diagram of market share changing