● M2.0 Allen wrench
● M4.0 Allen wrench
● Open-end wrench
Before replacing the Y-axis guide rails, make sure to turn off the printer and disconnect the power cable to ensure safe operations.
① Rotate the red knob on the Y-axis belt tensioner counterclockwise to remove it.
② Move the heated bed to the front and use a wrench or other tools to move the belt buckle fixed on the heated bed to the left and remove it.
③ Use an M2.0 hex wrench to unscrew the two screws that secure the tensioner.
④ Remove the tensioner and then take out the belt from the tensioner pulley.
Move the heated bed to the position of the motor at the back of the printer base.
① Use a wrench or other tools to move the belt buckle fixed on the heated bed to the left and remove it.
② Pull out the old belt.
③ Be aware that the other end of the belt buckle may get stuck at the edge of the guide rail when pulling it out. Adjust its position accordingly.
Use an M4.0 Allen wrench to remove the 2 screws at the marked position. (Since the Y-axis motor module and wiring are secured together with cable ties, you could place the Y-axis motor module within the range of movable wiring.)
Invert the printer.
Use an M4.0 Allen wrench to unscrew the four screws that secure the Y-axis guide rails and remove the old Y-axis guide rails.
Prepare the new Y-axis guide rails and ensure alignment with the corresponding positions on the bottom of the printer. Align the holes of the Y-axis guide rails with those on the printer base and initially secure them with suitable screws. Finally, use a M4.0 Allen wrench to tighten these four screws one by one, ensuring the Y-axis guide rails are firmly fixed to the printer base.
① Install the heated bed by gently pushing it in the direction of the Y-axis motor module, making sure not to let the pulleys hit the aluminum extrusion.
② Use an M4.0 Allen wrench to tighten the two screws that secure the Y-axis motor module.
First, move the heated bed to the position of the motor at the back of the printer base and take out the belt.
① Thread one end of the belt through the hole at the back of the Y-axis motor and guide it through the rail.
② Use your hand to secure the belt buckle to the sheet metal fixation.
③ Once secured, move it to the groove on the left.
① Thread the other end of the belt, which is not fixed, through the hole in the guide rail and loop it around the pulley.
② Move the heated bed to the side of the control panel (you could reference the axis core on the guide rail for specific positioning).
③ Secure the belt buckle to the sheet metal fixation.
④ Once secured, move it to the groove on the right.
⑤ Install the housing of the Y-axis tensioner, and use M2.0 to tighten the two left and right screws.
⑥ Rotate the tensioner knob clockwise.
Rotate the Y-axis tensioner knob clockwise until it is tightened, then rotate it counterclockwise one full turn.
Use an open-end wrench to adjust the hex eccentric spacer on the right side of the heated bed until the bed can be slide smoothly, and there is no noticeable wobbling when moving the bed from side to side. For a more detailed step-by-step demonstration, you could refer to the leveling guide video for Kobra 2:
. The relevant adjustment steps are shown starting from 57 seconds in the video. Follow the instructions in the video to ensure smooth movement and stability of the heated bed.
If the above replacement steps are not helpful, we suggest you create a support ticket to inquire with the after-sales engineer and explain the issues that were not clearly described in this guide. The after-sales engineer will assist you in resolving the problem. (Reply time :1 working day)
Please click this link to submit your ticket: