Our mill uses closed loop hybrid steppers. Each stepper motor has an encoder attached to it that reads and sends positional data back to the drivers. Due to its closed loop feedback, stepper drivers can send variable current to the steppers. This results in the steppers running far cooler and using less power than open-loop systems, therefore increasing lifespan. Thus closed loop stepper offer superior control of motion and no missed steps like with common open loop stepper systems. Because of this we can more efficiently use our steppers resulting in increased feedrates and accuracy. 

In the event that the drivers are unable to supply enough current to step, they will enter fault which will e-stop the machine. This protective safety feature is aimed to reduce potential damage or injury and allows for more peace of mind with the knowledge that you didn’t miss a step somewhere without realizing it. 

Milling feedrates can be assumed to be roughly 25% derated from rapid feedrates, though the actual amount varies due to factors such as material choice and cutter engagement. 

A spindle is the heart of the machine and is of critical importance to all operation. We use (4) oversized ABEC 7 7010 bearings in our spindle that are capable of speeds of over 12000 rpm. The spindle is configured for use with BT30 tool holders which is a standard tooling system available worldwide from innumerable suppliers. Rigid tapping and tool changing is achieved through closed loop feedback on the spindle. Vector frequency drive technology powers the spindle allowing maximum torque at any rpm.

Our homing method was not spared from scrutiny. Nothing is worse the have a machine error out in the middle of the job. If that happens you have to rehome the machine, but depending on the quality of the sensors, it doesn’t always home to the exact same positions. Our machine uses a Z index homing pulse in addition to inductive sensors. This means it will first home using the inductive sensor, then continue travel until the encoder on the stepper axis motor sends an index pulse. That means when it homes, it will home on the dot every single time. In addition, it also makes the ball screw map more consistent and increases repeatability of high tolerance parts. 

The mill comes with Centroid CNC control which is a robust, easy to use motion processing package ready to accept g-code from CAM packages or Centroids internal part programming conversational software INTERCON which can create programs through entering dimensions. Unlike other controllers, centroid uses a separate and dedicated computer and buffer for path planning alongside the main computer used for the graphical user interface. This division of computers provides protection from software interruptions that can occur for milliseconds, yet still enough time to result in incorrect paths being sent to the axis drivers. 

The cast iron frame is excellent for its vibration dampening characteristics and is the most common choice for machinery.  We have designed the machine to be compact enough to fit through a standard sized door.