5. Pulley sets

Lubrication

  • Toothed idler 20T B5 (3)

  • F604ZZ (16)

  • 604ZZ (8)

Although the pulleys have been lubricated in the factory, for high speed printing it is still recommended to add a few drops of light oil before assembly and constantly maintain.

Rear pulley sets

For 1 secondary belt tensioner (optional)

  • HK0408 bearing (2)

  • Bolt m4 x 25 (1)

  • Nut m4 (1)

  • Printed belt tensioner (STL here. A newer, easier print design has been updated in Oct 11, 2022)

Prepare 2 sets.


For 1 rear pulley set

  • Rear pulley housing (1)

  • F604zz bearing (4)

  • 604zz bearing (2)

  • Bolt m4 x 45 (2)

  • Nut m4 (6)

  • Washer m4 x 9 x 0.8 (2)

Prepare 2 identical, but not mirrored, rear pulley sets.


Exams

Pulleys should rotate freely.

(Drop the middle 604zz bearing if you want to use 6mm XY belts and further reduce some moving inertia 😁)

Actions

As shown in the pic below, optionally assemble 2 rear belt tensioners. It's recommended to put some lubricating grease into the bearings before assembly.

The secondary belt tensioners are not necessary. There are 2 major places for you to adjust belt tensions: XY stepper mounts and belt clamps at the extruder.


As shown in the picture below, assemble rear pulley sets using stacked F604zz (F = flanged) and 604zz bearings. Note that there is a washer as spacer between the F604zz and the rear pulley housing.


Optionally insert the secondary belt tensioners in the locations of the two rear pulley sets.

Belted-Z pulley sets


1 Z top pulley set

  • Z top pulley housing (1)

  • Bolt m5 x 40 (1)

  • Thin nut m5 (2)

  • Toothed idler 20T B5 (1)

Prepare 3 pulley sets. The left and rear pulley sets are identical. The right set has a different bolt orientation to prevent collision with the driving pulley.


Exams

The bolt head orientations are different.

Actions

Assemble pulley sets as the stacking order shown in the picture.

It's OK that pulleys can be shifted. Belt tension will keep them in position.

XY joiners

XY joiner

  • Aluminum XY joiner block

  • F604zz bearing (4)

  • 604zz bearing (2)

  • Bolt m4 x 45 (2)

  • Nut m4 (4)

  • Washer m4 x 9 x 0.8 (3)

Prepare 2 identical, but not mirrored, XY joiners.


Exams

Make sure pulleys are correctly placed in the left and right XY joiners. Pulleys should rotate freely.

Actions

Assemble the XY joiner as shown in the picture. Remember to place a washer as a spacer between the F604zz bearing and the XY joiner block.