Z-Axis Belt Assembly





Time Required

X Minutes



Step 1

Gather the Z-axis upper idler plate parts

  • Z-axis Idler Mount Plate (4x) B Level Foam
  • GT2 Belt Toothed Pulley (4x) Bag C-11
  • M5 x 25mm Socket Cap Screw (4x) Bag C-11
  • M5 Nut (4x) Bag C-11
  • M5 Nyloc (4x) Bag C-11
  • 3.0mm hex key, 8.0mm socket or pliers, Loctite Low Strength (recommended)
  • You will be building four identical assemblies.
  • Remove the protective plastic film from each side of each plate.

Step 2

Assemble the Z-axis idler plates

  • Insert the M5 screw through the plate.
  • Put a dab of Loctite on each screw thread near the panel.
  • Use the hex key to hold each screw while you use the socket or pliers to tighten the M5 nut snug against the panel.
  • Add a smooth pulley to the screw and start a nyloc, but don't tighten. Don't use Loctite on nylocs.
  • With your finger, spin the pulley and pay attention to how smoothly it runs. It should spin freely for several revolutions.
  • Use the 8.00mm socket or pliers to tighten the nyloc till it just starts to obstruct the pulley from spinning freely, back off just slightly so the pulley spins as well as it did a moment ago.
  • There should not be any side to side play in the pulley assembly
  • Repeat this step for the remainder of pulleys

Step 3

Gather and assemble the mounting hardware

  • M4 x 10mm Socket Cap Screw (8x) Bag C-10
  • M4 Tee Nut (8x) Bag C-10
  • Use the 1:1 screw chart to ensure you have the correct size hardware.
  • Insert screws from the same side as the others screws and loosely attach tee nuts a couple threads.
  • Populate all four panels.

Step 4

Mount the Z-axis idler plates

  • Mount the Z-axis idler plate to the top rail of the frame. The goal is to align the plates such that the belt wrapping up from the bottom will travel vertical and plumb to the top idler pulley.
  • The front plate should be 5 inches from the front of the machine. See picture.
  • The rear plate should be 5.5 inches from the back of the machine. See picture.
  • Ensure the tee nuts are rotated when you tighten them so that they bite into the V-Slot.

Z-axis idler plates mounted

Step 5

Mount C-Shape Alignment Tools

  • C-Shaped Alignment Tool (2x) X Level Foam
  • On each side of the frame, hang one C-shaped alignment tool and balance the lifting platform on it.
  • The alignment tool should hang about in the middle of the frame, front to back.

Step 6

Gather and assemble the belt capture screws/plates

  • M3 x 8mm Socket Cap Screw (8x) Bag C-13
  • Belt Capture Plate, Aluminum (2x) C Level Foam
  • 2.0mm hex key, Loctite Low Strength (optional)
  • Attach the screws and plates on each side of the machine to the corresponding Z-axis belt capture blocks.

Step 7

Position the Z-axis rod GT2 Pulleys

  • 3.0 and 2.0mm hex key, Loctite Low Strength (recommended)
  • Return to the Z-axis rod for a moment. Remember we haven't finalized the position of any of the GT2 belt pulleys? Lets do that now.
  • Use a 3.0mm hex key as a spacer between the singly GT2 belt pulley and side panel. Add a touch of Loctite to each grub screw, and then tighten them securely.
  • Be sure to do this to both belt pulleys. Leave the double belt pulley, we will tackle that later.

Step 8

Loop through the Z-axis belt (both sides)

  • Z-Axis belt (2x) Bag C-13
  • Starting at the belt screw block, loop one belt up over the pulley and down to the base.
  • Run the belt back over the Z-axis rod toothed pulley, and then to the pulley that will send the belt up vertically.
  • Thread the belt through the aluminum belt capture block, around the upper pulley and back down and then up to the belt screw block.
  • The loose belt ends should be even.
  • Repeat for both sides.

Belts on bottom side plate

Step 9

Prepare for belt tensioning

  • Clamps, line level, bulls-eye level
  • For the step, Belt Tensioning, you will find it easier if the machine is secured in place. I used a clamp to hold the machine to my workbench.
  • A bulls-eye level is provided in the kit. I used that on the X/Y carriage and moved the carriage to the center of the machine.
  • I also used a level on each side of the machine, centered around the C-Shape helper tool.
  • When you tighten the belts, you will want to check that the lifting platform is level in all directions.

Step 10

Install Z-Axis hand wheel

  • Z-Axis Hand wheel, 3D printed (1x) A Level Foam
  • Locate the Z-axis wheel and install it on the left or right side of the machine, your choice.
  • The part should slide on easily over the Z-Axis rod flange bearing.
  • Align the Z-axis hand wheel such that the slots in the shaft of it allow axis to the grub screws of the bearing.
  • The part may have a loose fit, and if this is the case, you can add just a small touch of glue or paper (as a shim) to secure the item.

Step 11

Belt tensioning

  • Pliers, 2.0mm hex key
  • Tight the plate on the belt capture block on both sides.
  • Using the pliers, pull the belts tight. Once tight, and even, tighten the screws to capture the belts. Do this to both sides.
  • Keep an eye on the level while tightening. If the lifting platform is not level after tightening, you can loosen the toothed pulley on the Z-Axis rod and rotate it as needed to raise or lower one side of the platform to make it level.
  • Take your time and get this right. It is critical to be as level in the X and Y axis as possible.

Belts tensioned and captured

Belts tensioned on bottom side plate

At this point in the assembly process, all axis of the machine should be complete. Move each axis through its range of motion to ensure belts and assemblies travel smoothly. Double check that the lifting platform is level in all directions.