The Z timing belt is a close drive belt with a pitch length of 1442mm, it is installed at the bottom of the Bambu Lab X1/X1C printer. It connects the Z motor and the Z rods and drives the heatbed to complete the movement in the Z direction.
1. Power OFF the printer before doing any maintenance work;
2. In the case where the belt is not broken, lower the heatbed to the bottom base and lock the Z sliders with screws;
3. Take care of the top glass cover plate and the LCD screen.
Tilt the screen up and press underneath with light force (see picture) to release the buckle and push rightward to unlock the high-resolution LCD screen.
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Press both sides of the FPC connector to unlock the connection and remove the LCD high resolution screen.
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Remove the top glass cover plate, flip the printer over and place the bottom side up so that you can see the Z timing belt.
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Release the torsion spring, and remove the black adjustment screw with an H2.0 hex key and the 3 sliver screws with an H1.5 hex key.
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Take off the tension pulley cover, and remove the torsion spring.
Remove the tension pulley assembly. Be careful with the nut inside the assembly, and do not lose it.
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Now you can take out and remove the Z belt easily.
Warning: Do not rotate the Z belt wheels alone; it will cause the heatbed to tilt.
Install the new belt to the printer, and place it as shown in the picture below. Make sure that the teeth side is facing inward.
Warning: Do not rotate the Z belt wheels alone; it will cause the heatbed to tilt.
Confirm that the nut is inside the assembly, and then install the tension pulley assembly into place.
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Install the torsion spring, noting that the shorter end is on the right side, and then place back the pulley cover.
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Lock the 3 silver screws with an H1.5 hex key to fix the cover, and prefix the black screw with an H2.0 hex key, do not tighten it. Bend the spring to place to make it tense.
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Move the Z belt back and forth several times to make sure the movement is smooth, and then tighten the black screw.
Note:
In the case of Z belt being broken, you need to confirm that the heatbed is level after the new Z belt was installed. Move the new belt to drive the bed to the bottom base, check that all the 3 sliders touch the bottom base, if there is a gap between the bottom base and the Z slider, then release the tension torsion spring, and rotate the Z belt alone to make the gap gone, and then reinstall the torsion spring.
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Turn the printer upright again and place back the glass cover plate.
Pull the FPC out and insert the FPC connector into the port at the back of the high resolution screen LCD by pressing both sides of the FPC connector.
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Insert the excess FPC cable into the printer, mount the LCD high resolution screen into the 4 slots of the printer, and push gently to the left until you hear the buckle click.
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Should you come across any issues, first retrace your steps and check the installations, especially the direction of the belt and the connection of the LCD screen, and try again. If problems persist, contact the customer support team for further assistance.