Below is the A axis. As you can see, this also has a stepper motor to drive the chuck round via a toothed belt.
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| This is a 4th axis or A axis in action. Photo is from China CNC Zone |
The stepper motors fitted to the 3020, 3040 and 6040 are very reliable, usually when there's a problem it's nearly always incorrect setup of software.
The steppers are just motors, they can rotate continually, or in very small steps in either direction with an accuracy of 0.05mm (0.002") making them ideal for engraving.
