Bipolar CNC Controller Setup

NOTE: This is for our bipolar CNC controller found on our 2011 Kickstarter project "Modular Desktop CNC". It has been replaced by our Unipolar CNC Controller from our 2012 Kickstarter project "CNC Building Blocks". See our new controller tutorial here.

REMEMBER. When configuring your CNC electronics, please unplug all connections from the back of your control box. Then wait a few minutes before opening your control box to make adjustments. It is possible for the on board capacitors to store a charge and potentially cause a shock. Please use extreme caution when working with high voltage sources. We are not responsible for damage caused to your electronics, computer, or motors.

Setting up Microstepping

Microstepping is possible with our control board. Microstepping is a way to force your stepper motors to move a fraction of a step instead of a full step. You can potentially increase the precision of your stepper motors by 16 times the standard amount for smaller movements. Note that due to the nature of microstepping, your electronics will reduce the power to the motors when microstepping, effectively reducing the torque produced by the motor. A high microstep setting will give very small movements, but much less power. The lack of power can cause your motors to not have enough power to move and can stall them.

Our electronics allow for a range of microstepping options. You are able to set microstepping in increments of 1/1, 1/2, 1/8, & 1/16. A setting of 1/1 means microstepping is not turned on, where 1/16 is the highest setting, which can allow the motors to spin in small amounts, with less power.

To set microstepping. Ensure the electronics are unplugged and no power is going to them. Let them sit for a few minutes before opening the cover and servicing. After waiting a few minutes you can open the cover by removing the four Phillips screws in the corners of the enclosure. Do not remove any other screws.

With the cover removed, look for the DIP switches with 4 switches in a row. There will be three of these switches in the center of the control board, one for X, Y & Z. Using a small screwdriver, pencil, pen or other small object, flip the switches in accordance with the table below for your desired setting:

Full Step (No Mircostepping) Full Step (No Microstepping)

Switch #3: Off
Switch #4: Off
1/2 Step 1/2 Step

Switch #3: On
Switch #4: Off

1/8 Step 1/8 Step

Switch #3: On
Switch #4: On
1/16 Step 1/16 Step

Switch #3: Off
Switch #4: On

Once you have changed your settings, you can put the cover back on your electronics, plug everything in and power the controller on. Your new switch settings will require you to change your motor's settings in Mach3. You will need to recalculate your steps per inch setting based on the new Mircostep setting. See our Stepper Motor Calculations page for more information.

Setting Stepper Motor Amperage

It is possible to change the current setting on our control board to use the system with several different sized stepper motors between 0.5 - 2.5 amps. You should change this setting to match the rating on your stepper motors when using new motors or making other changes.

To set the motor current, ensure the electronics are unplugged and no power is going to them. Let them sit for a few minutes before opening the cover and servicing. After waiting a few minutes you can open the cover by removing the four Phillips screws in the corners of the enclosure. Do not remove any other screws.

With the cover removed, look for the DIP switches with 2 switches in a row. There will be three of these switches near the end of the control board, one for X, Y & Z. Using a small screwdriver, pencil, pen or other small object, flip the switches in accordance with the table below for your desired setting:

100% Current

~2.5 Amps

Switch #1: Off
Switch #2: Off

75% Current

~1.8 Amps

Switch #1: On
Switch #2: Off

50% Current

~1.25 Amps

Switch #1: On
Switch #2: On

20% Current

~0.5 Amps

Switch #1: Off
Switch #2: On

Once you have changed your settings, you can put the cover back on your electronics, plug everything in and power the controller on. No further changes in software or configuration will be needed.