Y-Motor Replacement

Disconnect NOVA from power

Ensure that NOVA is turned off with the power button and then unplug the power cable.

Remove the backplate

With a T20 Torx bit remove the 6 screws (2 on the back side, 4 on the bottom of the panel) securing the back panel. Once the screws are out you can pull the back panel out by tilting it up slightly and then pulling away from the machine.

Locate the Y-motor

Now that the back panel is off locate the Y-motor in the bottom right corner of NOVA.

Remove the old Y-motor

Use the 2.5mm hex key to remove the 4 screws and washers securing the motor to NOVAs body and remove the old motor.

Disconnect the motor from the cable by wiggling it out (it has no locking tab or latch).

Insert the new Y-motor

Take the new Y-motor and plug in the cable. Insert the motor into the mounting bracket.

Using the 2.5mm hex key, loosely secure the motor in place with the 4 screws and washers.

Place the belt over the y-motor pulley and ensure that the teeth of the belt are fully engaged with pulley. Now roll the belt over the larger pulley to fully seat the belt.

Tension the Y belt

Using a second hex key push down on the top of the motor body to apply tension to the belt and tighten two of the four screws.

Using your phone and an online chromatic tuner measure the frequency of the belt when you pluck it (like a guitar string). It should measure between 274-293 Hz.

Adjust the position of the motor as needed to achieve proper belt tension.

Once you achieve proper belt tension tighten all four screws.

Reattach the backplate

Put the back plate back into place and with a T20 Torx bit secure the 6 screws (2 on the back side, 4 on the bottom of the panel).

Turn NOVA back on!

You can now plug NOVA back in and turn it on using the power button.

Install the Calibration Fixture

Attach the T shaped mounting fixture to the mounting grid at the below location, four mounting holes from the front. Use a 4mm hex key to tighten down the two bolts and secure the fixture.

Attach the dial gauge to the T fixture by engaging the tool port lever. Now turn on the dial gauge by pressing the green on/off button and zero the dial gauge by pressing and holding the origin button.

Run the Calibration Command

Open the console by clicking the ~ key and copy the below command block into the console. The command moves the tool mount forward and backwards in 1 mm increments; the goal is to find the difference between each shift and the absolute value is the compensation value.

M507 Y0;
G28;
V2 T0 X37 Y47;
G01 C-1;
G04 P3500;
V2 T0 Y25;
(V2 T0 Y1 F500; G04 P3500;
V2 T0 Y-1 F500; G04 P3500;)*10;
G28;

As NOVA moves back and forth take note of the values on the dial gauge focusing on the decimals. It can be helpful to take a video of the dial gauge to review the measurements after the test or have a second person reading out the numbers as it goes.

Again, we are calculating the difference between each shift and the absolute value will be our compensation value.

Once you have calculated the compensation value you can enter it in the console with the command below replacing the 'X' with your unique value.

M507 Y0.0XX

A compensation of 0.015 mm will look like the image below when entered into the console:

Confirm Calibration Value

You can confirm that your compensation value is correct by entering this command block into the console and taking note of the difference between each 1 mm shift.

G28;
V2 T0 X37 Y47;
G01 C-1;
G04 P3500;
V2 T0 Y25;
(V2 T0 Y1 F500; G04 P3500;
V2 T0 Y-1 F500; G04 P3500;)*10;
G28;

Repeat steps 2 and 3 until the calibration value is acceptable.

Remove the Calibration Fixture

Remove the dial gauge and mounting fixture using a 4mm hex key.