¶ What is XY timing belt
The XY timing belt is an open drive belt with a pitch length of 1442mm. There are 2 XY timing belts in the Bambu Lab X1/X1C printer. They connect the XY motor and the toolhead as well as drive the toolhead to complete movement in the XY direction.
¶ When to do
- Broken belt
- Belt aging & wear that has affected function
¶ Tools and materials needed
- H1.5 Allen Key
- New XY belt (Usually 1 PCS for broken belt, but 2 PCS for aging & wear)
- Quick dry glue
- Flat-tip tweezers or flat-blade screwdrivers
¶ Safety warning and machine state before starting operation
Power OFF the printer before doing any maintenance work.
¶ Operation guide
Before replacing the new belt, there are some key points that you need to remember.
- Do not pull out the broken belt before you begin the replacement, as you will need it for leads.
- The new belt should be oriented the same as the broken one.
- Confirm the path of the belt via the broken one before replacing it.
- Be slow when passing through the belt, stop and check when there is obvious resistance.
- The bond between the old and new belts should be strong enough.
¶ Step 1 - Lower the heatbed
Power ON the printer, navigate to the movement menu on the LCD display and lower the heat bed all the way to the bottom of the machine. Once done, power OFF the printer and remove the top glass cover plate.
¶ Step 2 - Removing the rear cover of the toolhead
Undo the 4 screws securing the back cover of the tool head using the Allen key and remove the back cover.
¶ Step 3 - Removing screws
NOTE: There are a lot of screws involved in this procedure. Please label them and group them in separate sections to avoid issues.
Remove the screws from the rear cover as pictured below (4 screws in the first picture, and 10 in the second). Be aware that there are 2 types of screw, and you will need to keep them separated to remember which screws to use for what areas when reassembling.
 |
 |
¶ Step 4 - Removing the rear cover
Remove the rear cover, and unlock the left side belt tension port first and then the right side one to avoid getting stuck.
 |
 |
¶ Step 5 - Removing the tension spring holder
Remove 2 screws and then remove the tension spring and its holder.
 |
 |
¶ Step 6 - Loosen the tension pulley assembly
Remove the 2 screws and the metal brackets, and then loosen the tension pulley assembly.
 |
 |
¶ Step 7 - Bonding new and old belts
Trim the fracture plane evenly and bond the old and new belts together with quick dry glue. Note that the belts must face in the same direction. Check that the bond is strong enough. In most broken belt cases, you will need to glue each end of the new belt to the broken old belt, but it depends on where the belt is broken. For the aging cases, you only need to bond one end of the new belt if you cut off the old one near the toolhead.
 |
 |
¶ Step 8 - Passing the new belt
With the old and new belts attached, you can pass the new belt through the idle idler pulleys and the motor unit. Take it slowly and carefully; you need to push the belt on one side and pull it on the other side. You can also use a tool such as a glue stick (shown below) to help you skip the motor gear. The difficulty of passing through the new belt depends on where the old belt broke.
 |
 |
¶ Step 9 - Removing the old belt from the toolhead
After you finish passing the new belt through, you need to unlock the old one from the toolhead. Remove one screw, and use a flat-tip tweezers or a flat-blade screwdriver to pry the stopper of the belt out from the toolhead, you can cut it off with scissors and remove the old belt. Don't forget that you need to do the same thing on the other side of the toolhead. (Pending updates)
 |
 |
¶ Step 10 - Attach the stopper
Attach a stopper to the end of the belt with quick dry glue.
¶ Step 11 - Installing the new belt to toolhead
Bend the belt and insert it into the slot, push the belt upward to place with an allen key.
 |
 |
 |
¶ Step 12 - Locking the belt
Push the fixed block of the belt into the gap, and then lock in 1 screw, it is OK when the screw head is in contact with the structure part, so do not tighten the screw too much to avoid bending things out of shape. Follow steps 12 to 14 to install the belt on the other side of the toolhead as well.
¶ Step 13 - Installing the tension pulley assembly
Install the tension pulley assembly, slide it into the position, and screw in 2 screws with metal brackets, but do not tighten the 2 screws yet.
 |
 |
¶ Step 14 - Installing the tension spring and its holder
Install the tension spring and its holder and lock in 2 screws. It may need a strong force to push and keep the holder in place while locking the screws. If you are installing a second belt, you can also follow steps 5 to 14 for that belt before continuing.
 |
 |
¶ Step 15 - Installing the rear cover of the printer
Pass through the tube bracket and the right side belt tension port first to install the rear cover.
|
|
 |
¶ Step 16 - Locking screws
Screw the back panel back on. Take note of the different types of screws used (10 and 4 as shown below).
|
|
|
¶ Step 17 - Tension belt
Loosen the 2 screws of the other tensioner, move the toolhead back and forth several times, and stop both ends of it to the rear, lock the screws on the 2 tensioners.
 |
 |
You can also get detailed information on tension belts from this wiki.
¶ Step 18 - Installing the rear cover of the toolhead
Re-install the back cover of the tool head and secure it with 4 screws (2 on each side).
¶ How to verify completion/success
- Power ON the printer
- Run a Device self-test operation as shown below and if no errors occur, the replacement was successful.
Should you come across any issues, first retrace your steps and retention the belt to try again. If problems persist, contact the customer support team for further assistance.