Installing the Nano Zero Stepper

Jan 1st 2017

his is a guide to installing the Nano Zero Stepper (NZS) on your stepper motor.

Attach Magnet to back of stepper motor

The NZS feedback loop is done by measure the rotation of the magnet included with your NZS. This magnet needs to be connected to the shaft on the stepper motor. This is done by using epoxy or super glue. The magnet will be glued to the back of the stepper motor on the shaft, it is recommended for the maximum accuracy that a nylon washer be glued between the stepper motor and magnet.

The nylon washer between the motor shaft and the magnet reduces the magnetic loss through the motor shaft, thus increasing the magnetic field for the encoder to read. The magnet shipped with the NZS is a “strong” magnet and will work without using the nylon washer between motor and magnet but the increased magnetic field with nylon washer is better for encoder.

Care should be taken to try and center the magnet on the shaft.

The glue should be allowed to dry before proceeding to attach PCB board.

Attaching PCB

The next step is to remove the four screws on back of the stepper motor in prep for installing the PCB board. Then using the screws and nylon washers included with the NZS attach the PCB to back of the motor leaving a small gap between the top of the magnet and the sensor IC chip as shown below.

Please note that different stepper motors might require different length screws for attaching the NZS to motor. The kit comes with 40mm long screws but if you need a different length screw please contact us and we will try and get you the right length screws for you motor.

The PCB design layout should have clearance for the screw head, however we recommended that the nylon washer be placed on the top side of the PCB as shown below.

Connecting Power

The blue screw terminals is for the Motor Power connections this power is normally 12V or 24V and should not exceed 40V. The positive terminal for the power connection is closest to the mounting screw, the negative is closest to the capacitor can. Please note that wiring the polarity of the motor power in reverse will fry the board.

Motor Connection

The NZS is designed for dual phase motors, ie stepper motors with 4 wires. The four wires on the stepper motor are connected internally to two sets of coils as shown below:

The easy way to determine which wires are which is by using an ohm meter, if there is resistance between two wires then the two wires are connected to the A or the B coil. The wiring to the NZS should be done as shown below.

It does not matter which coil (A or B) is wired to the top two terminals on the NZS or which direction the coils are wired as the firmware will detect this and correct for reverse motor wiring.

The NZS includes some crimp terminals and connectors for wiring up your stepper motor if you choose to use them.

Wiring to Ramps Controller

The next step is to wire the NZS to your controller, it will be assume that your controller uses Step Sticks (green modules shown below) like the Ramps controller one shown below.

With the NZS you will no longer need the step stick for your motor as the NZS has built in driver. On the axis you are putting the NZS on remove the step stick from the controller and then wire the power, ground, step and direction to the NZS. The wiring for the step sticks is shown below.

So to replace the step stick with the NZS you would wire the NZS pins to pins on the RAMPs board as shown below.

The VIN, GND, STP, and DIR should be connected to the pins on the NZS with the same names. The above diagram shows the connection for the X axis on the RAMPS only, the other axis have similar wiring.

The RAMPS boards have 5V logic levels, hence the VIN pin should be connected to the 5V VIN pin on the RAMPS board. Other boards like Smoothie which uses 3.3V logic will have slightly different wiring.

Note if you have the firmware set up for the ERROR pin on the NZS to be an ENABLE then you would include the enable wire as shown below, again the ENABLE would be connected to the ERROR pin on the NZS. If you are not sure which way your firmware is configured, do not connect the enable pin.

Connections for Smoothie or 3.3V logic boards

To be done shortly, if you need help please let us know.

Powering Board

When powering the NZS the motor power should be turned on before the VIN or USB power is applied.