Project Dashboard Accessories and Upgrades LulzBot TAZ 12V to 24V Upgrade Procedure Workflow

1 Getting Started

Before beginning, we need to make sure the following items are on hand:


  • 24V Power Supply
  • Assembled 24V Heated Bed
    If you do not have the above items stop and contact for further assistance.

You will need to print/source the following:


  • 2.5mm wrench (included with the TAZ toolkit)
  • Phillips screwdriver (included with the TAZ toolkit)
  • Dental Pick (included with the TAZ toolkit)
  • Needle Nose Pliers (included with the TAZ toolkit) or Wire crimps
24V Power Supply
24V Assembled Bed

2 Record Extruder Steps Per Unit

To determine current extruder step/mm settings:

If you have a TAZ with an LCD display:

  • Power on the TAZ 3D Printer
  • Navigate with the GLCD Controller to Configuration > Motion and scroll down to Esteps/mm
  • Record the number (3 digits). You will need this value later in this procedure.

If you do not have a TAZ with an LCD display:

  • Check the Test Acceptance Record for the steps/mm labeled E0
  • Record the number (3 digits). You will need this value later in this procedure.

If you do not have the paper work or cannot determine your extruder steps per unit stop and contact Lulzbot Technical Support for help by sending an email to

Record Esteps through Graphical LCD

3 Accessing the Fan

  • Power down the TAZ 3D printer and disconnect from both the electrical outlet and any USB connection.
  • Use the 2.5mm hex driver to remove the four screws on each corner of the electronics case.
  • Unplug the fan from the RAMBo board.
Electronics Enclosure
Unplug Fan

4 Change Pin Order

Reverse the pin order on the case fan connector if needed

The fan connector will need to be plugged into the connection labeled Fan2. If the fan is already plugged in at this location and working continue to the next step. If the fan is plugged into the connection labeled X30 continue with the instructions below.

Using the Dental Pick from the TAZ toolkit, remove the pins from the fan connector by pushing down on each tab on the black connector while pulling on each wire. Once removed, lift the locking tab on the connector pin to allow it to lock back in place once reinserted.

The red wire should go in Pin 2 (right), the black wire should be in Pin 1, and may be marked with a triangle on the left side)

5 Reconnect The Fan

  • Plug the case fan connector into the connector labeled Fan2.

Verify that the black wire is plugged into the board so that the black wire is on the same side of the board (left hand side) as the silver USB port.

Fan plugged in, Black Wire on the left

6 Secure the Electronics Cover

  • Use the 4 M3 screws and the 2.5mm driver to reattach the lid to the electronics case.
  • Make sure that all the wires clear the case edges and that nothing interferes with the fans operation.
Reattach the electronics enclosure

7 Allow the power supply to discharge

You will need to transfer the existing black printed power supply cover with integrated harness from the 12V power supply to the new 24V power supply.

Make sure the power supplies are unplugged from both the wall outlet and the TAZ 3D printer for at least 15 minutes prior to disassembly. Be careful not to short any of the terminals as there may be a residual charge present even though the power supply is unplugged.

Power supply unplugged and idle

8 Swap Power Supply Harness

  • Unscrew the power supply connector from the TAZ 3D printer electronics case.
  • Using your 2.5mm wrench remove the 3 M3 screws and washers from the 12V power supply and set aside. You will be using them on the new 24V power supply.
  • Now that the power supply cover is loose, tilt the cover down while keeping it close to the power supply, exposing the screw terminals and wiring.
Remove the screws on the black enclosure only

9 Disconnect the existing wires, noting the location and order.

  • Make a note of the current wire placement. You'll be follwing the same order
  • Disconnect the exisiting wiring harness from the power supply by loosening the the screw on each terminal block and removing the wire.
  • Once free from the 12V power supply, transfer the power supply cover to the 24V power supply.
  • Attach the wires from the power supply cover matching the order indicated in the picture.
  • Attach the electronics cover using the 3 M3 screws.
Power Supply Wiring

10 Firmware Changes

In order to use the new 24v power supply some firmare changes are needed

Download the Arduino IDE

  • Download the Arduino IDE, version 1.0.5 or higher:

    • Please note that this firmware may require a specific version of the Arduino IDE, version 1.0.5. 1.0.5-R2 is not compatible. Past versions of the Arduino IDE can be found on
  • Install the Arduino IDE

Downlaod Arduino IDE
Select Appropriate Installer File

11 Download the Firmware

  • Download the following file: marlin.tar.gz
  • Extract the archive and merge the folders found in the downloaded Marlin archive: ArduinoAddons/Arduino_1.xx to your local installation of the Arudino IDE. Merge the downloaded libraries folder with the original Arduino libraries folder. A guide can be found here.
  • Close and reopen the Arduino IDE once before continuing.

If you are unsure how to continue, contact LulzBot Technical Support by sending an email to:

Merge folders

12 Prepare the Printer

  • Plug in the TAZ 3D printer with both the power supply and with the USB cable.

13 Open the Arduino IDE

  • Launch the Arduino IDE and load the marlin.ino sketch found in the previously extracted archive
  • The file can be found in ../Marlin/marlin.ino
  • Select the tab labeled Configuration.h.
  • On your keyboard, press CTRL+F and search for the following text string: "DEFAULT_AXIS_STEPS_PER_UNIT"
  • Change the last 800 to the value you saved in step 1, or from your Test Acceptance Sheet the value labeled E0.
  • Save the changes.

14 Compile the Firmware

Verify the correct board is selected

  • In the Arduino IDE, select Tools > Board > Arduino Mega 2560 or Mega ADK
  • Select Sketch > Verify/Compile.

Continue if the sketch compiles with no errors and displays Done compiling. If the compiling fails, stop and contact for assistance.

15 Updload the Firmware

  • Select Tools > Serial Port and select the COM port normally used to connect to the printer through Pronterface. The RAMBo COM port will be listed in Device Manger for Windows users, and will be listed as a /dev/tty__ on linux systems.
  • Select File > Upload to upload the firmware to the RAMBo board.
  • Wait for the process to finish.
  • Check the bottom of the Arduino IDE window for any errors. If any errors are reported, try to upload the firmware again and contact for further assistance.
  • Power cycle the board by unplugging the USB cable and the Power Cord from the TAZ 3D printer.

16 Verify Firmware Operation

Test the board to verify correct operation

  • Plug in and power on the TAZ 3D printer.
  • Check the Graphical LCD controller to verify that the printer displays the correct ambient temperature in Celsius (usually 20-25C).
  • If the printer does not power on or correctly drive the GLCD controller contact for further assistance.
GLCD Home Screen

17 Remove the 12V bed

Power down the TAZ 3D printer before proceeding.

  • Disconnect the small thermistor connector from the bed wiring harness.
  • Disconnect the larger heater coil connector from the bed wiring harness.
  • Turn all 4 bed corner fingers away from the heated bed, to allow the heated bed assembly (glass and silicone heater) to lift off the Y axis.
  • Remove the 12V heated bed assembly.
Bed disconnected
Move Bed Fingers Away From Glass

18 Replace the Bed Corners

You will reuse the original screws, washers, springs and bed fingers. Make sure to save them.

  • Use the 2.5mm wrench to remove the screws holding the 4 bed corners in place.
  • Install the 4 new bed corners.
  • Move everything over from the old bed corners to the new bed corners.
  • Roughly align all four corners to the same height. Prior to your first print you will need to level the bed.
Bed Corner Assembly

19 Mount the new 24V bed

To assemble the 24V bed:

  • Place the 300mm Borosilicate glass on a clean flat surface.
  • Peel the adhesive backing off the silicone heater.
  • Align one corner of the silicone heater with the corner of the glass.
  • Apply the heater to the glass, moving slowly and maintianing the alignment.
  • Once the heater has been adhered to the glass, install the PET sheet onto the other side of the borosilicate glass bed by following the instructions found here:

With the assembled 24V bed:

  • Place the new 24V bed on the y axis.
  • Make sure that the bed is fully seated.
  • Secure each corner with the bed finger.
  • For the front left corner of the bed, rotate the bed finger clockwise, so the finger is half on/half off the bed, hanging onto the front edge of the glass bed.
Peel PET Backing
Start On One Side
Push Out Any Bubbles
Finished Bed

20 Test and Verify

  • Plug in and power on the TAZ 3D printer.
  • Check that the case fan spins freely. The case fan will not power on immediately upon startup. It will start after the TAZ has fully booted.
GLCD Home Screen

21 Level the Bed

Follow the instructions found in the User Manual in Section 4.1 (page 48).

Once leveled, print your favorite object to test your new 24V TAZ 3D printer!

Bed Level Print Check
Done! Take me home