Closed Loop Stepper Motors

CNC machine motion is split up into 4 sections, the controller, the motor driver, the motor and the machine.

When you create your gcode file for your CNC machine you need it as faithfully reproduced as possible, any slop in tolerance between your vision and the final product makes an entirely different product. Using MASSO closed loop stepper motors with MASSO controllers bring together 3 of the 4 steps for motion, controller, motor driver and motor.

MASSO produces differential signals for motor control, these are the same types of signals used in your fuel injected car, and for your ethernet network cables. Using differential signals reliably gets the signal from your MASSO controller to your MASSO closed loop stepper motors with differential signal receiver capability. So we have gotten the signal reliably from your controller to your motor, now what – well with MASSO closed loop stepper motors they take that signal, convert it into the power to drive your motor the required steps, then using an encoder to keep track of your motor shaft, it checks and confirms that you have reached your intended rotation. If the motor has overshot, or movement has been resisted, it can make minute adjustments giving them a repeatable accuracy of +- 0.9°. Because the motor can keep track, it can adjust the current draw and increase torque to meet its angle needs, maintaining the step count even at high resolutions.

MASSO can be used with open loop stepper motors and when set up properly an open loop stepper motor will work well with your MASSO controller. When doing a machine conversion the original motors can still be used whether they are open or closed loop motors.

Open loop stepper motors were once the mainstay of CNC machines with closed loop options hard to find and expensive. Technology has changed in recent years with closed loop stepper motors now a readily available and affordable option for the machine builder.

It is the closed loop motor’s ability to sense position, correct for positional error and report back to the controller problems that make the closed loop stepper motor a step up from its open loop counterpart.