Therefore, to get maximum torque out of your motors without overheating them, you should choose motors with a current rating no more than 25% higher than the recommended maximum stepper driver current. So the usual practice is to set the motor current to no more than about 85% of the rated current.
However, even with one winding driven at the quoted rated current, the motor will get very hot. The maximum current through one winding (which is what really matters when using microstepping) is rarely quoted and will be a little higher.
This is the maximum current you may pass through both windings at the same time. Ultimately, we still need only 4 wires to connect to the Duet. There's plenty of other documentation around the internet on how to do this, just make sure that the Duet can cope with the current requirement. You can run an 8-wire stepper in half-coil (with only 2 coils connected) or full-coil mode, and in full-coil mode you can choose to wire the coils in series or in parallel. See the motor specification to check that your Duet can supply enough current for how you want to wire them.Ĩ-wire stepper have 4 coils, so with two wires per coil, this makes 8 wires. You can choose to run them in half-coil, by leaving two end-wires unconnected, or full coil mode by leaving the centre wires unconnected. This creates an extra wire for each coil. With 6-wire stepper motors, there are still 2 coils, but each coil has a centre tap, effectively cutting the coil in half if needed.
The 4 wires map to the 4 output pins of each stepper driver on the Duet (see below for identifying phases and connecting). The wire and coil pairs are called a phase. Inside the stepper motor are two coils, each coil having a wire connected to each end. (Some unipolar motors can be made into bipolar motors by cutting a trace on a circuit board.) You cannot use motors with 5 wires, because those are intended to be driven in unipolar mode only. This means you can use stepper motors suitable for bipolar drive, which have 4, 6 or 8 wires. The Duet boards use bipolar stepper motor drivers.
0 kommentar(er)
