Chapter 06: Z-Axis Installation

This chapter details one of the most significant moments in the build: installing the completed gantry into the main frame. We will also connect the gantry to the Z-drives by routing and tensioning the four Z-axis belts.

Step 1: Assemble Z-Axis Joints

The four Z-axis joints are the interface between the gantry and the Z-axis linear rails.

1. Preparation: If you are using Hall Effect endstops, insert a 6x3mm magnet into the designated slot in one of the printed blocks. Also, press an M5 nut into each block.
2. Install Belts: Take a length of 9mm GT2 belt and clamp it securely into the serrated channel of the Z-joint block. Ensure the teeth of the belt face down into the grooves of the part.
3. Repeat for all four Z-joint assemblies.

A close-up view of a 9mm GT2 belt being clamped into the printed Z-axis joint block.

Step 2: Install the Gantry into the Frame

An Extra Pair of Hands Helps!

This step can be tricky to do alone. Ask a friend for help holding the gantry to prevent it from dropping.

1. Lower the Gantry: Carefully lower the entire gantry assembly into the printer frame. You may need to tilt it at an angle to get it past the frame's uprights.
2. Temporarily Secure: Use long zip ties or clamps to temporarily hold the gantry's weight, suspending it roughly in the middle of the frame. This frees up your hands for the next step.

Illustration of the gantry assembly being carefully lowered into the main printer frame, with zip ties shown for temporary support.

Step 3: Attach Gantry to Z-Rails

Attach the four Z-joint assemblies (with belts installed) to the MGN9 carriages on the vertical linear rails. This officially connects your gantry to the Z-axis.

A close-up showing a Z-joint being bolted to an MGN9 linear rail carriage.

Step 4: Route and Tension the Z-Belts

The Z-belts transmit motion from the motors at the bottom to the gantry.

1. Belt Path: For each corner, route the belt from the Z-joint down to the pulley on the Z-drive assembly, around it, and back up to the Z-idler at the top of the frame. Then, bring the belt end back down to the Z-joint.
2. Tension: Use pliers to pull the loose end of the belt tight, removing all slack.
3. Secure: While keeping the belt taut, securely fasten the second belt clamp on the Z-joint to lock the belt in place.
4. Repeat for all four corners. Your gantry should now be fully supported by the belts. You can remove the temporary zip ties.

A clear diagram showing the correct routing path for a single Z-axis belt, from the drive at the bottom, to the idler at the top, and connecting to the gantry.

Step 5: Gantry Squaring

Finally, ensure the gantry is square relative to the frame. Move the gantry all the way to the back of the printer until both sides make contact with the A/B drive housings. At this point, fully tighten all the screws that connect the XY joints to the X-axis. This ensures the X-axis is perpendicular to the Y-axis.