XY Pulley

This guide covers replacing the motor pulleys (toothed drive pulleys) on the 22 IDEX V4. The machine has four motor pulleys � one on each XY motor shaft:

Over time, pulley teeth can wear down, chip, or develop flat spots � causing belt skipping, layer shifting, or clicking noises during printing. If the pulley is fine but the motor itself is faulty, see the XY Motor Replacement Guide instead.

Pulley replacement requires removing the motor bracket. Two motors are mounted on the bracket. One motor is removed from the bracket to allow access to the second motor's pulley. Pulleys are replaced one at a time, then everything is reassembled in reverse order.

Tools and Materials

• 2.5 mm Hex screwdriver (hex wrench) � for top cover screws, motor bracket screws, and motor mounting screws
• 2 mm Hex screwdriver (hex wrench) � for cover limiter screws and pulley set screw
• Replacement motor pulleys
• Threadlocker (we recommend Loctite 243)
• Guitar tuning app on your phone (for verifying belt tension at 65 Hz after reassembly)
• Small container or magnetic tray (to hold screws and small parts)

Removing Belt Tensioners

1. Fully unscrew the belt tensioning knobs on the front of the machine, turning counter-clockwise. Remove them completely.

2. Catch the washer behind each knob � it will fall off as you remove the knob. Set the knobs, springs, and washers aside.

3. Pull the belt tensioners out of their housings so they hang freely on the belts.

Disconnecting Motor Cables

4. Disconnect the cables from the motors (two motors on one bracket). Grip the connector body � not the wires � and pull straight out.

Removing the Top Cover

5. Unscrew the eight screws holding the top cover using the 2.5 mm hex screwdriver.

6. Unscrew the two screws holding the cover limiter using the 2 mm hex screwdriver.

7. Remove the top cover from the printer.

Removing the Motor Bracket

8. Unscrew the two screws on the top gantry that hold the motor bracket using the 2.5 mm hex screwdriver.

9. Unscrew the two screws on the side wall that hold the motor bracket using the 2.5 mm hex screwdriver.

10. Pull the bracket toward you � it will stretch out with the belts still attached.

11. Slip the belts off the motor pulleys and remove the bracket from the printer.

Removing the First Motor and Replacing Its Pulley

12. Unscrew the mounting screws of the first motor using the 2.5 mm hex screwdriver.

13. Remove the motor from the bracket. Note the motor orientation relative to the bracket.

14. Loosen the set screw on the removed motor's pulley using the 2 mm hex screwdriver.

15. Slide the pulley off the motor shaft. Note how far down the shaft the pulley was seated � you will need to replicate this position when installing the new pulley. You can replicate this measurement using A4 paper: fold it 4 times and use it as a distance spacer.

16. Slide the new pulley onto the motor shaft at the same position. Rotate the pulley so the set screw hole lines up with the flat side (D-cut) of the motor shaft.

17. Tighten the set screw firmly with the 2 mm hex screwdriver. The pulley should not wobble or slide on the shaft.

18. Spin the pulley by hand. It should rotate smoothly with no wobble. If it wobbles, loosen the set screw, re-seat the pulley, and tighten again.

Replacing the Pulley on the Second Motor (on the Bracket)

19. Loosen the set screw on the second motor's pulley � this motor stays on the bracket � using the 2 mm hex screwdriver.

20. Slide the pulley off the motor shaft. Note the pulley position on the shaft.

21. Slide the new pulley onto the motor shaft at the same position. The flat side of the shaft (D-cut) must align with the set screw.

22. Tighten the set screw firmly. The pulley should not wobble or slide on the shaft.

23. Spin the pulley by hand to verify no wobble.

Installing the First Motor Back on the Bracket

24. Position the first motor on the bracket in the same orientation as before.

25. Apply threadlocker to the mounting screws.

26. Insert the screws and tighten evenly using the 2.5 mm hex screwdriver.

Reassembly

27. Loop the belts back onto the motor pulleys. Make sure the teeth face inward toward the pulleys.

28. Install the bracket with motors back into the printer. Apply threadlocker to the screws. Insert the two screws on the side wall and tighten with the 2.5 mm hex screwdriver.

29. Insert the two screws on the top gantry with the 2.5 mm hex screwdriver. Apply threadlocker to the screws. After all 4 screws are started, tighten them.

30. Place the top cover back on the printer. Insert the eight top cover screws and tighten with the 2.5 mm hex screwdriver. Use threadlocker. Pay attention to the cables that pass through the cover spacer. They should pass through freely.

31. Insert the two cover limiter screws and tighten with the 2 mm hex screwdriver.

32. Reconnect the motor cables to the connectors on the motors. Match the connector orientation to the photos taken in step 4.

Reinstalling Tensioners and Belt Tension

33. Insert the belt tensioners back into their housings.

34. Place the washers onto the tensioning knob shafts. Screw the knobs back in clockwise.

35. Set belt tension to 65 Hz using a guitar tuning app. For the full tensioning procedure, see the Belt Tensioning Guide.

36. Repeat the full procedure for the other side if pulleys on both sides need replacement. The process is identical.

37. Slide the gantry and toolheads manually across their full range of travel. Movement should be smooth with no binding or unusual noise.

Troubleshooting

• Issue: Pulley slips on the motor shaft during movement.
• Cause: Set screw not tightened against the D-cut flat.
• Solution: Power off, loosen the set screw, align it with the D-cut flat, re-tighten, and verify the pulley height matches the belt path.

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• Issue: Belt rubs against the edge of the pulley.
• Cause: Pulley installed too high or too low on the shaft � not aligned with the belt path.
• Solution: Loosen the set screw, adjust the pulley position on the shaft so it lines up with the idler and other pulleys, and re-tighten.

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• Issue: Belt tension won't reach 65 Hz.
• Cause: Belt was not re-seated properly on the motor pulley, or belt shifted during installation.
• Solution: Re-seat the belt on the pulley, verify all belt routing, and re-tension. See the Belt Tensioning Guide.

FAQ

Q: Do I need to remove the motor to replace the pulley? A: Yes. Pulley replacement requires removing the motor bracket. One motor is removed from the bracket to allow access to the second motor's pulley. See the step-by-step instructions above.

Q: Do I have to replace all four pulleys at once? A: No. Replace only the pulleys that are worn or damaged.

Q: How do I know if the pulley needs replacing? A: Inspect the teeth � if you see chipped, rounded, or missing teeth, replace the pulley. Also check for wobble by spinning the pulley by hand with the belt removed.

Q: Do I need to recalibrate after replacing a pulley? A: Yes � run the full auto-calibration procedure after any work on the motion system. See the Auto-Calibration Procedure.

Support

If you could not find an answer here, reach out to our support team.