This guide will show you how to replace a standard bowden ERC unit with a Direct Drive ERC unit. You can also use it as a guide to swap out a Direct Drive ERC for a new single or dual ERC unit.

You will need a #10 Open End wrench, and a 3mm and 4mm hex wrench.

Turn off the printer and unplug the power cord.

Remove the top panel or hood.

Remove the 4 large screws located on the top of the ERC.

Now disconnect the limit switch in the front top left corner as well as the two motor connectors.

Remove the 4 screws and take off the back panel.

Remove the bowden tube from the bottom of the extruder assembly by pressing on the black circular press connector. Skip this step if you are replacing a direct drive ERC.

Cut and remove the zip ties from the wiring harness.

Disconnect the ERC wires from the RAMBO board.

Clear the belt from underneath and remove the ERC from the printer.

Un-package the new ERC.

Feed the wires through the back panel of the AXIOM.

Install the new ERC in to the top of the printer.

Position the belts so that they are clear of any obstacles and can move freely.

Install the 4 large screws into the top of the ERC plate. Fully tighten after all screws are loosely in place.

Now connect the motor wires, then the top front limit switch. The black wire goes on the left post, and the white wire goes on the right.

Go to the back of the machine. Plug in the ERC wires into the correct plugs and pins on the RAMBO board. The wiring diagram can be found here.

Add new zip ties to the wiring harness.

Reinstall the back panel

Plugin the power cord and turn on the printer.

Open the APEX software.

Connect to the printer via USB cable.


Now choose AXIOM, then DUAL or SINGLE head, then select DIRECT DRIVE.

Now go to FINISH.

Go Back to MACHINE, then choose INSTALL DEFAULT FIRMWARE, then DIRECT DRIVE. Choose the version of firmware that you previously used. If you are unsure, start with version D and go down from there if the nozzle is too far from the glass on the first layer.

Click on OK after choosing the firmware, then allow the firmware to upload on to the printer. The printer will reboot. Wait 5 seconds, then turn the printer off and back on.

Confirm the new Firmware version at the bottom of the screen.

From the screen, auto-home the printer in order to make sure each limit switch triggers at the end of each axis. If there is an error, check the RAMBO board connections.

Now Preheat the printer to the material’s temperature that you will be using.

Install the glass build plate into the heat bed brackets.

Apply Wolfbite to the glass if the bed has not heated yet. If it has, do this step before heating the glass.

Pull the filament latch on the hot end out and then up. Then pull the lower bearing arm down.

Load the filament into the hot end.Apply slight pressure to the filament until you see material coming out of the nozzle.

Close the lower arm, then secure the latch.

Now install the dome to the top of the machine, making sure the filament comes in through the back slot.

The AXIOM is now ready to use.

FAQ's and troubleshooting:

Machine doesn't move in X or Y properly, or goes the wrong direction:

 -Y limit switch was not plugged in correctly, or not at all.

-X or Y motors plugged in in correctly, not seated fully

-X microswitch connector not plugged in correctly

-Belts are pinched underneath the front of the frame

-Belt has fallen off a pulley/bearing

Z overshoots, or doesn't move when the print starts.

-Z probe not connected properly, or isn't working

-bed rail isn't clean

Hot end doesn't heat:

-Actual temperature never goes up more than room temperature: hot end heater is not connected properly

-Actual temperature reads 0: MINTEMP alarm; thermistor is not plugged into the correct spot, or wires are pulled out/damaged

-Gets hot, then starts cooling, or fails to get to temp, or fails to stay at temp: Poor connection on the hot end heater connector; or defective heater cartridge.

First layer seems closer or further away immediately after ERC was replaced (nothing else):

-Bed rails aren't clean to new nozzle

-Firmware was flashed to be a different version due to nozzle wear, and now that there's a new nozzle, it needs to be changed back

-Slice settings were for a different nozzle size. We are assuming you are using our slicer, APEX, with defaults for your first print. The default nozzle we install on an ERC swap is 0.5mm.

There is a puff of smoke and a burning smell from the heat block. There's now a MINTEMP error.

-You plugged thermistor 1 into the print fan port on the board. You'll need a new thermistor. Let your AIRWOLF technician know and we can re-swap ERC's.