Project Dashboard Hot End & Tool Head Assembly LulzBot Mini 2 AeroStruder Assembly Workflow

1 Gather Components

Gather the required materials:
1x- [AS-HE0025] Mini2 AeroStruder v2 Hotend Assembly
1x- [AS-CB0063] 220mm HotEnd Ground Wire
1x- [AS-CB0062] Blower fan Harness, 250mm
1x- [AS-CB0061] Extruder Motor Harness, Mini2
1x- [AS-CB0064] Heatsink fan Harness, 220mm
1x- [AS-CB0066] Thermistor Harness, 120mm
1x- [PP-IS0057] Mini2 Aero Blower Shroud w/ Inserts
1x- [PP-IS0053] Mini2 Aero Extruder Mount w/ Inserts
1x- [EL-MT0040] NEMA 17 Half Height Stepper Motor, Moons
4x- [HD-BT0039] Socket Head Cap Screw, Alloy Steel, M3 Thread, 12MM Length, 0.50MM Pitch
1x- [HD-BT0042] Socket Head Cap Screw, Alloy Steel, M3 Thread, 30MM Length, 0.50MM Pitch
3x- [HD-BT0043] Socket Head Cap Screw, Alloy Steel, M3 Thread, 35MM Length, 0.50MM Pitch
1x- [HD-BT0146] M3 x 12 BHCS, Black Oxide, Class 10.9 Steel
1x- [HD-BT0171] Black Oxide Steel Button-Head Screw M3 Size, 20 mm Length, .5 mm Pitch
1x- [HD-BT0197] M4 Thumb Screw for Aero
1x- [HD-MS0430] Idler Spring for Aero
2x- [HD-MS0446] MR95-2RS Radial Ball Bearing Double Sealed Bore Dia. 5mm OD 9mm Width 3mm
1x- [HD-NT0011] M4 Nut, Steel, Zinc Plated
1x- [HD-WA0027] Stainless Steel Internal-Tooth Lock Washer, M3 Screw Size, 6MM OD, .4MM Min Thick
1x- [HD-WA0038] Black-Oxide 18-8 Steel Flat Washer, M3 Screw Size, 3.2mm ID, 7.0mm OD
1x- [PP-FP0135] E3D Aero Idler Lever
1x- [PP-FP0136] E3D Mirrored Aero 2.85mm Filament Guide
1x- [PP-FP0137] E3D Aero Acetal Gear w/ Filament Drive Shaft
1x- [PP-MP0204] Aero Mirrored Body w/ Threaded Insert
1x- [PP-MP0205] E3D Aero Steel Pinion Gear w/ set screw

Required components

2 Install drive gear onto motor

Install the drive gear [PP-MP0205] onto the motor [EL-MT0040] using the printed drive gear spacer jig as shown. Torque the set screw to 5 in * lbs.

A set screw should come pre-installed in the gear, if not, ensure an M3x3 set screw is used. Set screws of any greater length will interfere with the larger gear during operation.

Thickness of the printed spacer is 5mm

Pinion Gear and Motor
Use printed jig to position gear
Torque the set screw

3 Install internal lock washer & sealed bearing

Install one sealed MR95ZZ bearing [HD-MS0446] into the extruder body [PP-MP0204] as shown.

Install the internal lock washer [HD-WA0027] as shown.

Aero Extruder Body & Sealed Bearing
Aero Extruder Body with Bearing installed
Aero Extruder Body with bearing installed & internal tooth lock washer
Lock washer installed

4 Assemble extruder body, mount and motor

Using one M3 x 12 BHCS [HD-BT0146], fasten the extruder body [PP-MP0204] to the motor through the printed mount [PP-IS0053].

Motor, Body, Mount and M3x12 BHCS
Mount orientation on motor, ensure the motor's connector is facing you
Tighten Body onto Mount & Motor

5 Verify correct nozzle

To verify the correct nozzle size is being used check to make sure there are no dot marking around the nozzle.

0 markings = 0.25mm

1 marking = 0.30mm

2 markings = 0.35mm

3 markings = 0.40mm

6 markings = 0.50mm

4 markings = 0.60mm

5 markings = 0.80mm

6 Install bearing into heatsink

Install the bearing [HD-MS0446] into the heatsink [AS-HE0025] as shown.

Bearing ready for installation in heatsink
Bearing installed in heatsink

7 Install drive gear-hobb assembly

Install the large drive gear [PP-FP0137]. Make sure the faces of the two gears are flush with each other. Adjust the pinion gear as necessary. If adjustments are required, make sure to re-torque the pinon gear set screw.

ready for assembly
assembled
make sure the gears are flush

8 Install idler and spring assembly

Install the idler [PP-FP0135]] and the idler spring assembly [HD-NT0011], [HD-MS0430], and [HD-BT0197].

Materials ready for assembly
Assembled

9 Install filament guide path

Install the filament guide path [PP-FP0136] as shown.

Materials
Filament guide path installed

10 Install zero sense line, fan duct, and heatsink assembly

Install the heatsink assembly [AS-HE0025] onto the Extruder Body as shown.
Route the heater cartridge wires and the thermistor wires as shown.
Put the zero sense line [AS-CB0063] onto one of the M3x35 SHCS [HD-BT0043], then put it into the lower right mounting hole as shown.
Lift the zero sense line fastener out part way and slide the blower shroud [PP-IS0057] over the hotend.
Put in the other two M3x35 SHCS [HD-BT0043] into the top two mounting holes, and put the M3x30 SHCS [HD-BT0042] into the lower left mounting hole.
Make sure not to pinch the zero sense line.
Torque the fasteners to 3 in * lbs in the sequence shown in the photo.
Route the Hotend Ground wire as pictured.

Heatsink & Extruder Body/Mount
Fit Heatsink into place as pictured
routing
materials
Fastener in place; note routing of the ground wire
blower shroud in place
Routing of the hotend ground wire
torque sequence

11 Install Blower Fan

Using one M3 x 20 BHCS [HD-BT0171] with a washer (HD-WA0038), install the blower fan [AS-CB0062] as shown.

Route the wires around back by the motor connector.

Materials
Secure with M3x20 BHCS with washer
Route the blower fan harness behind the motor's JST connector

12 Apply Warning Sticker

Apply 1x- 0.5mm "Hot" Warning Sticker [DC-LB0155] to the part cooling fan, exactly as pictured.

Warning Sticker applied to cooling fan

13 Install Heatsink Fan

Using four M3 x 12 SHCS [HD-BT0039]. install heatsink fan [AS-CB0064] as shown.

Assembly, Heatsink Fan, and fasteners
Attach the Heatsink Fan as shown below
Route the Heatsink Fan wires as pictured

14 Connect motor and thermistor harness

Connect motor harness [AS-CB0061] and thermistor extension harness [AS-CB0066] as pictured

Materials
harnesses routed and connected
Motor Harness connected

15 Pin all harnesses to the connector

Pin all harnesses to the connector according to the diagram, excluding the hotend ground wire until the next step.

Pin assignments
Connector pinned

16 Wrap the hotend ground wire and pin

While pinning the hotend ground wire last, wrap around the bundle of wires once or twice as pictured before pinning.

Hotend Ground wire wrapped and pinned

17 Electrical test

After assembly of the TAZ AeroStruder is complete, it is necessary to verify the electrical properties of the toolhead, namely the heater cartridge and thermistor.

Refer to the pin-out diagram above for pin locations

First we will test the resistance value of the heater cartridge;
To do so, first set your multimeter to Ohms which is signified by the capital Greek letter Omega.
Now touch the probes of your multimeter to pins 3 & 13 individually.
Note: Positive or negative probe positions are irrelevant to this test.
The display on the multimeter should now show a value around 19 Ohms.
Any value between 12.8 and 14.4 Ohms is acceptable, values outside of that range are cause for rejection of the heater cartridge and it should be replaced.

Next we will verify that the heater cartridge DOES NOT have continuity to the ground circuit.
To do so, the multimeter may remain in Ohms mode or be switched to an audible continuity test mode by moving the switch to the symbol representing sound waves.
Now touch one probe to the heater block, and the other to pins 3 and then 13, individually.
Note: Positive or negative probe positions are irrelevant to this test.
Whether probing pin 3 or 13, the multimeter display should remain at 0 and no audible alarm should sound.
This indicates that there is no continuity between either lead of the heater cartridge and the toolheads ground circuit.
If the multimeter display reads anything but 0, or an audible alarm is heard during either half of this test, the heater cartridge must be rejected and replaced.

Next we will perform the same tests for the thermistor.
To do so, first set your multimeter to Ohms which is signified by the capital Greek letter Omega.
Now touch the probes of your multimeter to pins 9 & 19 individually.
Note: Positive or negative probe positions are irrelevant to this test.
The display on the multimeter should now show a value between 80 and 120 K Ohms.
Pay close attention to the units displayed on the multimeter's display; the letter 'K' should be displayed to the right of the value.
If a reading is given in Ohms or Mega Ohms (indicated by the letter 'M' to the right of the value displayed) or the kOhms reading is too low (values displayed as 1.xx or similar) or otherwise outside of the range stated above, the thermistor must be rejected and replaced.

Next we will verify that the thermistor DOES NOT have continuity to the ground circuit.
To do so, the multimeter may remain in Ohms mode or be switched to an audible continuity test mode by moving the switch to the symbol representing sound waves.
Now touch one probe to the heater block, and the other to pins 9 and then 19, individually.
Note: Positive or negative probe positions are irrelevant to this test.
Whether probing pin 9 or 19, the multimeter display should remain at 0 and no audible alarm should sound.
This indicates that there is no continuity between either lead of the thermistor and the toolhead's ground circuit.
If the multimeter display reads anything but 0, or an audible alarm is heard during either half of this test, the thermistor must be rejected and replaced.

To finalize this test, verify that the zero sense line (ground circuit) has continuity to the nozzle.
This test is best performed in the audible continuity mode.
Touch one probe to the nozzle or heater block, and the other to pin 8 on the toolhead's connector.
Note: Positive or negative probe positions are irrelevant to this test.
An audible alarm should sound indicating that continuity is present.
If so, the toolhead has passed electrical testing and may proceed to final extrusion testing.
Congratulations!

Multimeter in resistance (Ohms) mode
Multimeter in audible continuity test mode

18 Extrusion test and remove filament from extruder

Put the toolhead onto the test stand and run the test gcode.
Make sure:
1) The heatsink fan is on anytime the tool's controller is powered on
2) That the blower fan runs without being too noisy or jittery
3) That the Hotend heats up in a controlled way
4) The stepper motor moves without skipping

Visually verify the extrusion and make sure there is no debris.

Remove the remaining filament from the tool head

Done! Take me home