Removing the XY Belt
Step 1: Release the XY Tensioner
Loosen the XY tensioning screws on the back of the printer with an H2.0 hex wrench.

Step 2: Remove the XY Belt Fixing Blocks
Use the H2.0 hexagon wrench to remove the three screws (M2.5x5) of the belt fixing block and remove the belt from the toolhead.
Do the above for both sides of the toolhead.
Then use a hex wrench to push against the belt holder, pushing it out slightly, and remove the belt holder from the belt. You can then take out the belt.

Step 3: Bonding the Belt
With one end of the old belt freed, you can use the quick-drying glue to carefully align the end of the old belt with the replacement one and glue them together (with belt teeth facing the same direction).
Hold them together carefully until the glue has set.
You can use to the same glueing method for replacing either or both XY belts.

Step 4: Install the Belt Fixing Block
Thread the free end of the new belt through the belt fixing block.
Then attach the belt holder to the end of the new belt, meshing their teeth together.
Pull the belt so the holder is pulled through the belt fixing block and secured back in place.
You can use to the same method for to fix either belt in place.

Installing XY belt
Step 1: Route the XY Belt
Pull the other end of the old belt, routing the new belt behind the old belt and through the idlers and motors which make up the belt path.
Work slowly and carefully. You can feed the belt by pushing from one side while pulling from the other, using the pull to guide the new belt fully through the printer.

Step 2: Remove the Old XY Belt
When the new belt is fully routed through the belt path, you can tear the old belt from the new belt and clean remaining glue from the end of the new belt.
Remove the other end of the old belt from the other belt fixing block and belt holder (as was done in Step 1: Remove the XY belt fixing blocks).
Mount the new belt to this other belt fixing block and belt holder (as done in Step 3: Install the belt fixing block).

Step 3: Install the Belt Fixing Block
Install the belt fixing block onto the toolhead and tighten the three M3×8 screws using an H2.0 hex wrench. When installing one side, it is recommended to push the toolhead all the way over to the other side.
Because the belt is under tension, push and hold the belt clamp into place by hand, then tighten the three M3×8 screws with the H2.0 hex wrench. It’s recommended to tighten the middle screw first.

Step 4: Tighten the XY Belt Tensioner
Move the toolhead 3 to 4 times in each direction, then tighten down the XY Belt Tensioner screws on the back of the printer.

Verifying Success
The toolhead should move normally, the idler on the tensioner should rotate without unusual noise, and there should be no errors indicating abnormal or low belt resonance frequency.
If you encounter any problems, review the steps and check all connections before trying again. If the problem persists, please contact the Bambu Lab customer service team for further assistance.