How to check and tighten motor pulley - Me3D Support

How to check and tighten motor pulley


When to check and tighten a motor pulley

You should check for a loose pulley on one of your printers axes if your prints have slanted, staggered or shifted layers, or if you've noticed one your printers axes not moving correctly. This may look like the belts are loose and slipping during prints, an axes not moving at all or no extrusion.
Inspection takes just a few moments, maintenance may take up to 15 minutes as and when required.

What do I need?

- 1.5mm hex key (included in your printers maintenance kit).

How to check for a loose pulley

Step 1 - Determine where the problem is

- The easiest way to identify which pulley is causing problems is by looking at the prints the printer is producing. The slanted, staggered or shifted layers will occur along the affected axis. Inconsistent extrusion or no extrusion at all with no clicking noise may indicate a loose pulley in the extruder.
- Print a Cali-cat from 'Featured Models' in BuildBee and observe where the fault occurs.

Step 2 - Check the pulley

- Check the belt tension on the affected axis. If the belt tension is good, but your prints have any of the issues described above, the pulley is most likely loose.
- You may also use the manual controls in BuildBee and observe the movements around the pulley. If you can see the motor shaft turning but the axis does not move, the pulley is loose.

How to tighten a loose pulley

Y axis

- Move the Y axis (print bed) all the way to the right to reveal the pulley. 
- Take the right hand endcap off so the belt becomes loose. This will make it easier to work with the pulley. Put the screws somewhere safe.


- Turn the pulley around with your hand so that one of the grub screws aligns with the flat side of the motor shaft. 
You may need to loosen both grub screws first.
- Making sure the pulley is aligned flush with the top of the motor shaft, tighten one of the grub screws against the flat side of the motor shaft so that the pulley no longer moves freely. Then, tighten the other grub screw against the motor shaft. 
Don’t attempt to tighten the screws too much, you may round off the grub screw.


- Carefully pull the belt tight again and put the screws back in.

X axis

- Lift the extruder arm off the bed using the manual controls in BuildBee.
- Move the X axis (extruder arm) forward or back until you can see the two grub screws on the pulley.


- Take the endcap off the back of the X axis (extruder arm) so the belt becomes loose. This will make it easier to work with the pulley. Put the screws somewhere safe.
- Turn the pulley around with your hand so that one of the grub screws aligns with the flat side of the motor shaft. You may need to loosen both grub screws first.


- Making sure the pulley is aligned with the groove of the axis and tighten one of the grub screws against the flat side of the motor shaft so that the pulley no longer moves freely. Then, tighten the other grub screw against the motor shaft. 


Don’t attempt to tighten the screws too much, you may round off the grub screw.
- Carefully pull the belt tight again and put the screws back in.

Z axis

- Lift the extruder arm up off the bed and prop it up with something (a filament box works well). If you can’t quite access one of the grub screws for the Z axis pulley, move the extruder arm up a bit more until you see them.


- Loosen the first grub screw and then move the axis up until you can access the other one. Loosen the second grub screw and let the extruder arm rest on the object thats propping it up. Careful not to let the axis drop.
- Turn the motor shaft around using the up and down manual controls in buildbee until the flat side aligns with one of the grub screws.


- Making sure the pulley is aligned with the groove of the axis, tighten one of the grub screws against the flat side of the motor shaft so that the pulley no longer moves freely. Then, move the extruder arm up until you're able to tighten the other grub screw against the motor shaft. 
Don’t attempt to tighten the screws too much, you may round off the grub screw.
- Remove the prop and return the extruder to the home position.

Extruder

- From the home position, move the extruder arm up 50mm and forward 50mm.


- Remove 3 of the screws from the extruder fan and rotate it away as shown in the picture below:


- Loosen 3 of the 4 screws so they are free of the motor but still holding everything else together.
- Hold the motor with one hand and undo the last screw with the other so that the motor doesn't fall.



- Carefully remove the motor from the rest of the extruder. You can rest it on the base plate if you like.


- Remove the cable from the motor to make it easier to work with.
- Loosen the 2 grub screws and position the pulley so that it is approx 5mm out from the motor (approx in the middle of the motor shaft).



- To double check the positioning take the back half of the plastic feeder (??) and thread it back onto the motor. The gear has to align with the wheel.


- Tighten one of the grub screws against the flat side of the motor shaft. Then, tighten the other grub screw against the motor shaft.
- Put the motor back into the rest of the extruder, making sure the clip for the cable is on the bottom.


- Replace the 4 long screws, then swing the fan back around and replacing the 3 smaller screws. Remember to tighten the screw at the pivot point as well.
- Plug the cable back into the motor, being careful not to damage the pins. Return the printer to the home position.

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