Project Dashboard Hot End & Tool Head Assembly LulzBot Mini Hexagon Hot End Assembly Workflow

1 Gather required tools and parts

Required Tools:

Torque wrench with 7mm crows foot adapter

18mm open end wrench

4.5mm open end wrench

1.5mm hex screwdriver

2mm hex screwdriver

Resbond 907TS Blue thread sealant

Required Parts:

1 Hexagon thermistor with wires cut to 195mm and male pins crimped on ends

1 Hexagon heater cartridge with wires cut to 180mm and male pins crimped on ends

1 ground wire for nozzle, red 24AWG wire cut to 210mm with ground lug on one end and male pin on other

1 Hexagon heater block

1 Hexagon heat sink

1 0.5mm Hexagon nozzle (should say 5 on side)

1 thermistor retention plate

1 M3x4mm set screw

1 M2x6 SCHS

1 star lock washer

2 M3x8 stainless steel button head screws

Required parts

2 Install nozzle in heater block

If the nozzle came installed in the heater block, remove it.

Make sure that the nozzle says 5 on the side (0.50mm nozzle)

With the heatsink out of the heater block, install nozzle using a 7mm torque wrench and holding the heater block with a 18mm wrench.

Tighten to 30 in*lbs. .

Make sure that the nozzle is seated well into the torque wrench adaptor
Tighten the nozzle to 30 in*lbs

3 Install heatsink to heater block

Shake the bottle of threadlock well to ensure it is well mixed.

Apply a generous coating of high temperature threadlock to the threaded portion of the heatsink, except for the last 2 threads as shown. This will ensure a good seal and that no locktight makes it's way down to the nozzle.

Install in the heater block tightly using a 4.5mm wrench and holding the heater block with a 18mm wrench.

There will be a significant amount of thread-lock on the top of the extruder block. Wipe off any that drips over the side, but leave the thread-lock around the heat-sink extension as a visual indication that there is thread lock on the threads.

Before the threadlock compound sets (within 5 minutes), rotate the heat-sink so that one of the points of the heat-sink faces the front and the set screw hole is somewhere in the back.

Lock the threaded extension into the heatsink using an M2x6 SCHS with a small amount of high temperature thread lock.

Shake up the threadlock before each application to make sure it's mixed well
It's better to err on the side of too much threadlock than too little
Tighten the heatsink into the heater block with the 4.5mm and 18mm wrenches
It's good to have some threadlock on top of the heaterblock, wipe any off that runs over the sides or down the back of the heater block
This is the ideal orientation of the heatsink to the heater block (point forward, set screw hole in back)

4 Install thermistor into heater block

Take thermistor and pull back both pieces of the black shielding 1/2”

Make sure that the inner clear plastic tubing is all the way down to the bead of the thermistor

Slide ONE of the pieces of black shielding down to the bead of the thermistor and insert into the heater block, making sure that the shielding doesn't slide up from the bead of the thermistor.

Make sure small translucent insluation is all the way to the glass bead
Make sure that small translucent insulation is STILL all the way down to the bead of the thermistor
Slide the thermistor as far as it will go into the hole of the heaterblock, making sure that none of the insulation moves up from the glass bead of the thermistor

5 Install heater cartridge and retention plate

while holding the thermistor in place, slide the heater cartridge into the heater block so that the wires are coming out of the same face as the thermistor.

Secure heater cartridge and thermistor into the side of the heat block with a retention plate and an M3x6 BHCS.

Make sure that both leads of the thermistor are in the channel in the side of the heater block and not pinched against the flat face. One of the 2 black shield bits should be secured by the retention plate, the other should rest flush with the top of it.

Be sure that the retention plate is tightened seated completely flush against the block

Make sure that the front edge of the plate is parallel to the front face of the heater block.

Make sure that the retention plate is covering part of the heater cartridge, and that the wires are aligned vertically so that neither of the leads are touching the metal plate.

Plate installed, note that one of the bits of black wire shielding is sitting on top of the plate, the other is pinched by the retention plate

6 Lock heater cartridge in place

Pull heater cartridge up against the retention plate

Make sure that the wires are aligned vertically and that neither of the wires are close to touching the retention plate

Lock into place with am M3x6 set screw from the rear of the heater cartridge (no need for locktight here)

Cartridge installed correctly

7 Install ground lug

Attach ground lug to the left side of the heater block using an M3x6 BHCS and star lock washer between the ground lug and the heater block.

make sure that the wire is facing toward the heatsink so it can be routed with the other leads

correct orientation of ground lug, note that the star washer is between the lug and the heater block

8 Review print head

Review the printhead!

When you're done, twist the wires together to make them less likely to tangle with others in the batch

Done! Take me home