Editors:

Marcin Jakubowski

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Graphic Design:

Jean-Baptiste Vervaeck

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Version:

Date:

Universal Gearless Extruder

v1.0

August 18, 2020

Open Source Ecology Production Manual Series

Table of contents

Prelude: Notes on Using this Guide

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1. Introduction
2. Bill of Materials
3. Tools
4. 3D Prints, Cut, Prep
5. Build
6. Testing
7. First Run
8. Troubleshooting and Repair

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Appendix

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Chapter 1

Chapter 2

Chapter 3

Chapter 4

Chapter 5

Chapter 6

Chapter 7

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Notes On Using this Guide

TED Talk Link

ABOUT: This guide - the Universal Gearless Extruder Build Guide- is part of a production manual series for the 50 Global Village Construction Set machines. The intended audience is people interested in building machines, producing kits, running immersion build workshops based on this kit, and anyone else interested in collaborative, open source production.

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HOW TO USE: You can use a QR code reader to scan the bar codes to access content online.

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COLLABORATION: This is a collaborative effort. You are invited to help edit this guide. You can edit this document or make a copy, make your edits, and email us describing your proposed changes. To join our open source product development effort, see the Getting Involved page on the OSE wiki. You can email us at info@opensourceecology.org

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You can read the history of OSE’s extruder development here. This guide shows how to:

1. Source the parts for the extruder
2. Get heat sinks made
3. Assemble the extruder
4. Test the extruder

1. Introduction

OSE’s 3D printer extruder

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5. Build 0

Part Identification

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Identify:

1. Primary Extruder 3D Printed Piece
2. Secondary Extruder 3D Printed Piece
3. Idler piece

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5. Build 1

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Heater Block Preparation

• Unpack heater block from bag (1).
• Screw in the 2 heater block screws lightly (2)
• Screw in the thermistor screw lightly, so it still allows thermistor to enter (2)
• Insert heater cartridge with wire on the side of the indent (4-5)
• Insert thermistor with wire pointing in the same direction as heater (5)
• Screw down the thermistor screw lightly using a 1 mm allen wrench to fasten the thermistor, but very lightly as the screw can go right through the thermistor (5)
• Screw down the 2 larger screws using a 2 mm allen wrench, so that heater is secured (6). Do this evenly by screwing down one screw then the other and alternating 4 times
• Screw in the 1.2 mm extruder nozzle, until there is 1/2 thread exposed (7)
• Screw the heat break on the other side (8). Leave the thin nut (8) off for now.

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5. Build 2

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Heat Tighten

1. Heat tighten by connecting the heater to the power supply for 2 minutes. Once hot, place the heater block in a vise, hold the heat break with pliers, and screw down the nozzle with a 7 mm socket or adjustable wrench. Make sure that the nozzle bottoms out against the heat break, not against the heater block- the goal is to close the filament flow gap between nozzle and heat break.
2. Once tightened, disconnect power from heater element
3. After cooling so you can touch it again, screw on the 6 mm thin nut on the heat break
4. Screw the thin nut down until one thread is exposed under the nut.

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1/2 thread exposed

under nozzle

5. Build 3

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Add Heat Sink

1. Bend the heater cartridge wire out of the way so you can screw on the heat sink. Hold the bottom of the heater wire with pliers so that you can bend the heater wires down without breaking them from the heater cartridge.
2. Apply thermal paste to the heat break, to cover all threads
3. Screw on heat sink.
4. Stop where the break sticks out 2 mm above the heat sink.

Use pliers to tighten the thin nut against the heat sink to lock the heat break in place:

If the heat break sticks out too much, that means that the nozzle will be too high to reach the print bed (it will not reach below the body of the extruder and there will be interference of extruder with print surface.

5. Build 4

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Assemble Extruder

1. Clean off the 3D printed extruder pieces.

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2. Clean out the idler large hole with a ¼” drill bit

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Drill through 2 motor mount holes with 3 mm drill bit

Drill out the 3 secondary extruder piece mount holes with 3 mm drill bit

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But do not drill out the fan mounts

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Drill out the idler piece hole with 3 mm drill bit

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5. Build 5

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• Add an m6 nut in the indentation in the middle of primary extruder piece, over the hole.

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• Mount the stepper motor. Fit a stepper motor and attach upper right corner using an m3x8 screw and a 2.5 mm allen driver.

Stepper plug should be facing up

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• Mount the secondary extruder piece to the main extruder piece using [3] m3x18 mm screws

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• Attach the heat sink assembly to the stepper motor using m3x30 screws and a 2.5 mm allen driver. Keep loose to adjust exact location later.

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Be careful about stripping the small screw and small threaded hole in stepper motor. Start by screwing in the small screw into stepper motor hole WITHOUT

the 3D printed piece in the way to get a feel for how easily the screw should go in.

5. Build 6

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• Mount drive gear loosely on the stepper motor shaft. Insert a piece of 3D printing filament into the heat break, and align the extruder gear with it. Once gear is aligned, tighten down the gear with m2 Allen key.

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• Use Loctite semi-permanent thread locker on the drive gear set screw.

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• Press-fit idler bearing onto idler piece.

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• Mount idler on extruder. Use an m3x18 screw.

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5. Build 7

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• Insert the filament into the heat break again to align heat sink side-wise. Loosen the 2 heat sink screws. Move the heat sink left so that the filament is straight up, and tighten the screws down on the heat sink. Now that alignment has been done - you can attach the fan and fan heat sink.
• Take out the right screw, and heat paste the front of the heat sink
• Mount the fan heat sink on the right screw.
• Loosen the left heat sink screw, add more heat transfer paste where heat paste is missing,
• Mount fan heat sink on the left side with the m30 screw.
• Tighten down both fan heat sink screws to fix the fan heat sink in place, making sure that the sample filament is straight up vertically as before.
• Insert spring into the extruder
• Put heat paste on top of the heat sink and Do not tighten down fully, as the heat sink location will be adjusted.
• Tighten down the heat sink once the gear is aligned, with the inserted 3d printing filament as the guide
• Mount the fan using 2 of the small screws.

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Filament out of heat break bends slightly left

Filament goes straight up

5. Build 8

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Other Components and Wiring

1. Screw on the fan with the fan blowing into the extruder. Use m2.7 self-tapping screws.
2. Screw the blower to the secondary extruder piece using two m3x18 screws
3. Insert the height sensor and screw it down using an m6x18 bolt. The bottom of the blue plastic should be 4 mm above the nozzle tip
4. Connect the 1 meter long stepper wire to the extruder motor.
5. Bundle the wires such that when looking at the front of the extruder, the wires are sent to the right hand side. Use a zip tie to hold the wires together,
6. There should be 6 sets of wires, totaling 15 wires: fan, blower, heater, thermistor, height sensor and extruder motor.
7. Insert the wires through the split wire loom. That is it, the extruder should look like this:

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