the opn 3d printer: an inexpensive, open-source handheld
TRANSCRIPT
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The OPN 3D Printer: An Inexpensive, Open-Source Handheld 3D Printer
Abhishek Chandra*, John Giannini
St. Olaf College, 1520 St. Olaf Avenue, Northfield, MN 55057
*Email: [email protected]
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Table of Contents
Introduction……………………………………………………………………………………….3
Constructing the OPN 3D Printer…………………………………………………………….......4
Constructing and Configuring the OPN 3D Printer Temperature Control Box………….4
Constructing and Configuring the OPN 3D Printer Handle and Gear Mechanism……..17
Using the OPN 3D Printer……………………………………………………………………....24
Hazards…………………………………………………………………………………………..29
Acknowledgements and Disclosures…………………………………………………………….29
References…………………………………………………………………………………….....30
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Introduction
In the past twenty years 3D printing technology has rapidly evolved and continues to expand its
utility in additive manufacturing. Today 3D printing has utility in a number of industries from
automobile repair to medical technology (1-3). With decreasing costs, commercial printers have
become readily available for the casually interested (2, 4). These printers, while powerful, are
prone to errors that can mar prints or render them ineffective. The most common errors in prints
are gaps or holes in the solid (3-5). This can result in a loss of detail or function depending on the
print. This has been a challenge in designing many of the prototypes in our own lab (The OPN
Lab). These mistakes are often caused by errors in the G-code or incomplete object scanning
when developing an STL file (2, 5). Often, the only fix to such a problem is to repeat a print
using a slower print speed (3). This can be an expensive and time-intensive process. To the best
of our knowledge, there is not an easy method of printing on a previously cooled solid to fix any
errors.
In an effort to avoid or fix these errors, research is being done to refine 3D printing technology.
A number of handheld printers are available for sale, such as the LESHP® 3D Printing Pen
(and similar models from vendors like Sunveza®, NEXTECH®, and 3Doodler®). However,
these devices are relatively expensive with costs ranging from $50.00 to $150.00, not including
shipping or tax. Furthermore, many of these personal handheld printers suffer from limitations of
the types of useable filament.
As a way to bring down the cost of handheld 3D printers and make the process of print
correction more widely available to all, this manual describes how to 3D print and construct a
personal handheld 3D printer with an estimated cost of $25.00 when using self-printed parts.
This manual also describes how to use this handheld 3D printer to fix gaps and errors in prints so
that any user can repair existing prints without reprinting an entire project.
Finally, in keeping with the names given to the other instruments and pieces of equipment
developed in the OPN Lab, our handheld 3D printer is called the OPN 3D Printer. This name is
used because the device’s plans and parts are intended to be open-source and publically available
for all to use. We hope that the OPN 3D Printer will be a useful tool in the development and
production of 3D printed designs.
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Constructing the OPN 3D Printer
The construction of the OPN 3D Printer uses 3d printed parts and items readily available online
or in most hardware stores (an extruder head, temperature control board, and 12V power source).
For readers without access to 3D printing technology, there are a number of online vendors
(Shapeways®, makexyz®) that will print and ship any STL files for a fee based on the size and
volume of the part. http://3dprintingpricecheck.com/ estimates a cost of $28.30 to print the
required STL files for the OPN 3D Printer using makexyz 3D printing service (value calculated
in August 2017). In the long term, purchasing a mainline commercial 3D printer ($500 or less)
and the related filament ($25 or less) will be a more economical option, especially if printing
multiple parts over time.
Constructing and Configuring the OPN 3D Printer Temperature Control Box
To make and configure the OPN 3D Printer Temperature Control Box, readers will need the
following materials:
Standard 3D printer and related filament (ABS filament was used; PLA will suffice)
CAD and STL files for the OPN 3D Printer Temperature Control:
http://pages.stolaf.edu/opn-lab/equipment/
DC 12V K-Type Digital Thermostat (LM YN® Digital Thermostat K-Type DC 12V Red
Light, Temperature Controller Board and Module Switch, X0017QMRP3)
1.75mm Filament Extruder Hot End (Haobase® Assembled Extruder Part Hot End for 3D
Printer, 1.75mm Filament Direct Feed 12V Extruder with 0.4mm Nozzle, X0015F8HC3)
12V, 3.5Amps AC Adapter (TCP Electronics Co. LTD 12V AC Adapter, Model Number:
ADBC12350BB)
#4 14.7mm length steel slot screws (4X)
Tapping screw with M6 x 0.75 tap
Power drill with 0.25inch drill bit
5.0inch insulated copper wire
Metric ruler
5
STEP 1:
Print the STL files for the OPN 3D Printer temperature control box (Available on The OPN
Lab website).
Using a power drill and a 0.25inch drill-bit, bore a hole 14.55mm deep in the center of both
columns found in the back plate.
With an M6 x 0.75 size tap, use a tapping screw to cut threads in the bored holes. (Fig. 1)
Figure 1: The image shows the numbered ports and threaded columns of the back plate.
1 2 3
Threaded Columns
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STEP 2:
Loosen screw caps 1-6 on the back of the digital thermostat. (Fig. 2A-B)
Remove the blue and red ends of the temperature control element from screw caps 1 and 2 of
the digital thermostat.
Run the blue and red ends of the temperature control element in through port number 2 of the
back plate.
Secure the red end of the temperature control element under screw cap 1 of the digital
thermostat.
Secure the blue end of the temperature control element under screw cap 2 of the digital
thermostat.
Tighten screw caps 1 and 2 on the back of the digital thermostat. (Fig. 3)
Figure 2A: The image shows the front face of the digital thermostat and the attached
temperature control element. A
A
Temperature Control
Element
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Figure 2B: The image shows the back face of the digital thermostat with numbered screw caps.
Figure 3: The image shows the proper wiring of the temperature control element to the digital
thermostat through the back plate.
B
1
2
3 4 5 6
1 2
1
2
3
8
STEP 3:
Remove the thermocouple attached to the filament extruder hot end. (Fig. 4A-B)
Strip 0.5 inches off of the ends of both red wires of the heating element leading away from
the filament extruder hot end.
Run one of the stripped red wires of the heating element in through port number 1 and the
other stripped wire in through port number 3 of the back plate.
Secure one of the stripped red wires of the heating element under screw cap 3 and the other
under screw cap 6 of the digital thermostat. (Fig. 5)
Figure 4A: This image shows the filament extruder hot end and attached thermocouple.
Figure 4B: This image shows the filament extruder hot end with the thermocouple removed.
Thermocouple
A
B
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Figure 5: This image shows the correct wiring of the filament extruder hot end to the digital
thermostat through the back plate.
3
2
1
3
6
10
Step 4:
Strip 0.5 inches of insulation off of both ends of the 5.0inch insulated copper wire.
Run one end of the insulated copper wire in through port number 1 and the other end in
through port number 3 of the back plate.
Secure one end of the insulated copper wire under screw cap 4 and the other end under screw
cap 5 of the digital thermostat. (Fig. 6-7)
Figure 6: This image shows the correct wiring of the copper wire to the digital thermostat
through the back plate.
3
2
1
4
5
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Figure 7: This close-up image shows the correct wiring of the temperature control element,
filament extruder hot end, and copper wire to the digital thermostat.
Step 5:
Strip 1.5 inches off of the output end of the AC adapter cord. Separate the exposed wires into
two bundles. (Fig. 8)
Run both stripped bundles of the AC adapter cord in through port number 3 of the back plate
Secure one stripped bundle of the AC adapter cord under screw cap 3 and the other bundle
under screw cap 4.
Tighten screw caps 3, 4, 5, and 6 on the back of the digital thermostat. (Fig. 9-10)
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Figure 8: This image shows the AC adapter with output cords stripped and separated into two
bundles.
Figure 9: This image shows the correct wiring of the AC adapter cord to the digital thermostat
through the back plate.
3
2
1
3
4
13
Figure 10: This image shows the correct wiring of the temperature control element, filament
extruder hot end, copper wire, and AC adapter cord to the digital thermostat.
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Step 6:
Orient the digital thermostat such that the holes in the upper corners of the thermostat align
with the bored holes in the column and the display is visible.
Using two #4 14.7mm steel slot screws, secure the digital thermostat to the back plate. (Fig.
11)
Figure 11: This image shows the digital thermostat secured to the back plate.
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Step 7:
Use a hex driver to loosen the hex screws securing the port of the filament extruder hot end
adjacent to the heating element port.
Use a 0.25inch drill bit to drill the port adjacent to the heating element port.
With an M6 x 0.75 size tap, use a tapping screw to cut threads in port of the filament extruder
hot end adjacent to the heating element port. (Fig. 12A)
Insert the temperature control element of the digital thermostat into the threaded port of the
filament extruder hot end.
Use a hex driver to tighten the hex screws to secure the temperature control element in the
threaded port. (Fig. 12B)
Figure 12A: This image shows the filament extruder hot end with the port to be threaded.
Figure 12B: This image shows the filament extruder hot end with the attached temperature
control element.
B
A Port to be
drilled and
threaded
Temperature
Control Element
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Step 8:
Place the front plate over back plate.
Use a power drill and a 0.25inch drill-bit, bore a hole 14.55mm deep in through the side of
the front plate and into the back plate. (Fig. 13A)
o The hole should be placed 13.66mm from both the face and back of the front plate
and 1.3mm from the top edge of the front plate.
o The hole must be made on both the right and left sides of the temperature control
box.
With an M6 x 0.75 size tap, use a tapping screw to cut threads in the bored holes.
Using two #4 14.7mm steel slot screws, secure the front plate to the back plate. (Fig. 13B)
Figure 13A: This image shows the correct location of the bored hole in the front plate.
Figure 13B: This image shows how the steel slot screws secure the front plate to the back plate.
B
A
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Constructing the OPN 3D Printer Handle and Gear Mechanism
To make and configure the OPN 3D Printer Handle, readers will need the following materials:
Standard 3D printer and related filament (ABS filament was used; PLA will suffice)
CAD and STL files for the OPN 3D Printer Temperature Control:
http://pages.stolaf.edu/opn-lab/equipment/
Traxxas 3955 40-T Spur Gear (0.5 x 3.13 x 4.88inch)
Power drill with a 0.25inch drill bit
4.0mm steel slot screw, 33mm in length
2x2inch square steel sheet (2X)
4.4mm steel hex nut (2X)
4.0mm steel hex nut
Epoxy glue
Step 1:
Print the STL files for the OPN 3D Printer handle (Available on The OPN Lab website)
(Fig. 14)
Figure 14: This image shows the printed handle piece.
Top Bottom
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Step 2:
Use a power drill and a 0.25inch drill-bit, to bore holes through the centers of two 2x2inch
steel sheets.
With an M6 x 0.75 size tap, use a tapping screw to cut threads in the bored holes.
Step 3:
Screw one 4.4mm steel hex nut onto the screw of the filament extruder hot end. Make sure
the hex nut is tight against the base of the hot end.
Screw one 2x2inch steel sheet onto the screw of the filament extruder hot end. Make sure the
steel sheet is tight against the hex nut.
Screw one 4.4mm steel hex nut onto the screw of filament extruder hot end. Make sure the
hex nut is tight against the steel sheet.
Screw one 2x2inch steel sheet onto the screw of the filament extruder hot end. Make sure the
steel sheet is tight against the hex nut. (Fig. 15)
Figure 15: This image shows the correct order of steel sheets and hex nuts on the filament
extruder hot end.
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Step 4:
With an M6 x 0.75 size tap, use a tapping screw to cut threads 0.25inches deep in the
opening at the base of the handle. (Fig. 16)
Screw the threaded base of the handle piece 0.5inches onto the screw of the filament extruder
hot end.
Figure 16: This image shows the tapping screw threading the base of the handle piece.
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Step 5:
Print the STL file for OPN 3D Printer gear piece twice (available on The OPN Lab Website).
(Fig. 17)
Figure 17: This image shows the printed gear piece.
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Step 6:
Use epoxy glue to stick the two printed gear pieces to the spur gear such that the raised lips
on the printed gears touch either side of the spur gear and their openings are continuous. (Fig.
18)
Place the complete gear mechanism in the opening at the top of the printed handle piece,
aligning the holes in the center of the gear mechanism with the holes in the lips of the handle
piece.
Run a 4.0mm steel slot screw through the continuous opening such that the complete gear
mechanism is supported by the handle’s lips and is allowed to freely rotate.
Screw a 4.4mm steel hex nut onto the protruding slot screw, creating a secure axle. (Fig. 19-
20)
Figure 18: This image shows the fully assembled gear mechanism.
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Figure 19: This image shows the correct assembly of the gear mechanism in the handle piece.
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Figure 20: This image shows the fully assembled OPN 3D Printer.
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Using the OPN 3D Printer
Using the OPN 3D Printer safely and effectively requires an understanding of both the digital
thermostat and the gear mechanism. To turn on the OPN 3D Printer plug the AC adapter into
any three-prong household or industrial electrical outlet.
Setting the Digital Thermostat:
The main window/panel displays the current real-time temperature after the power supply is
plugged in.
Buttons:
ENT: This is the confirm key. Press it once to select a setting value. Holding the key for
five seconds will turn the thermostat on and off.
Set: This is the settings key. Press it to enter the main menu at any time.
+: This is the plus key. Press it to increase the value or setting displayed on the panel.
-: This is the minus key. Press it to decrease the value of setting displayed on the panel.
Main Menu Settings
Press Set to enter the main menu. Cycle through options F1 through F5 using the + or –
buttons. Press SET to enter a particular setting option. Press ENT to leave the main menu
F1: This option sets the desired temperature in degrees Celsius and can be adjusted using
the + or – buttons.
F2: This setting sets the work model of the thermostat. H is heating. C is refrigeration.
For printing, this must be set to heating (H).
F3: This setting sets the hysteresis or the number of degrees the thermostat must decrease
in order to function again after overheating.
F4: This setting controls temperature correction. The value displayed here is the number
of degrees above or below the set desired temperature the thermostat will allow before
correcting to the desired temperature.
F5: This setting sets the high-temperature alarm. This is setting is off by default and can
be adjusted to any temperature between 0 to 4990C
Codes:
LLL/HHH: This indicates that the temperature control element is either not connected or
malfunctioning.
Pattern/RRR: This indicates that the current mode is set to refrigeration.
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Pattern/HHH: This indicates that the current mode is set to heating.
Start Light: This light indicates that the device output has started and the relay has been
closed.
Using the Gear Mechanism:
The OPN 3D Printer is designed to accommodate any 1.75mm filament. However, ABS
or PLA filament is recommended. Once the device has been turned on, the digital thermostat
must be set according to the recommended values for the filament in use. Once the appropriate
temperature is reached a piece of the desired filament at least 20cms in length should be fed
through the opening at the top of the Handle piece. Take care that the filament is nestled in the
groove behind the gear mechanism such that the metal spur gear is in contact with the filament.
Pushing down on the filament should force extrusion from the filament extruder hot end.
The gear mechanism is similar to that of a standard laboratory pipette. Pushing up on the
gear mechanism or turning the gear in the forward direction will push filament down towards the
hot end (Fig. 21-23). The speed and force applied on the gear mechanism controls the speed of
filament extrusion.
If the gear mechanism does not push down filament or turn with ease, industrial grease
can be used to lubricate the axle and gear piece. If the gear mechanism is not contacting the
filament, make sure that the filament is properly nestled in the channel in the open portion of the
handle piece. This can be seen by holding the handle piece so that the gear mechanism is facing
opposite to the user. Filament that has slipped out of the channel can be adjusted using a small
pick or tweezers.
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Figure 21: This image shows the correct direction of rotation of the gear mechanism for
extrusion.
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Figure 22: This image shows how the OPN 3D Printer can be used to fill gaps in a print.
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Figure 23: This image shows gaps in a print filled using filament extruded by the OPN 3D
Printer.
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Hazards
There are a number of safety hazards associated with 3D printing. In particular, the 3D printing
bed can become very hot when in use. Readers should exercise caution when removing any
prints from the printer bed. Also, the 3D printing process can release harmful nanoparticles into
the air, which can cause several serious health issues, including asthma attacks, respiratory
arrest, strokes, and even cardiac arrest. Readers should keep their 3D printer in a well ventilated
area and wear proper protective equipment when operating the printer (e.g., masks or respirators
and goggles or safety glasses to protect their respiratory systems and eyes from these
nanoparticles). We encourage readers to review the safety information pertaining to their 3D
printer, and research to learn more about 3D printing safety. The OPN 3D Printer has a heat sink
designed to dissipate heat from the filament extruder hot end to avoid burning the operator. It is
highly recommended that a pipette stand be used to hold the OPN 3D Printer when not in use.
Use caution when operating the device and do not touch the filament extruder hot end and
attached wires when the device is in use. Upon turning off the device, allow two to three minutes
for proper cooling of the metal.
Disclosures
I declare that I have no conflicts of interest related to any product, brand, company, website, or
other item discussed in this manual. As well as with other open-source instruments and
equipment developed by this lab, we encourage readers to improve upon the designs and
methods set forth in this manual by using other materials and equipment. We urge them to bring
their own insights and inspirations to the project.
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References
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3D printing and its potential impact on biotechnology and the chemical sciences.
4. Kietzmann, J., Pitt, L. and Berthon, P., 2015. Disruptions, decisions, and destinations: Enter
the age of 3-D printing and additive manufacturing. Business Horizons, 58(2), pp.209-215.
5. Kruth, J.P., Leu, M.C. and Nakagawa, T., 1998. Progress in additive manufacturing and rapid
prototyping. CIRP Annals-Manufacturing Technology, 47(2), pp.525-540.
6. Lipson, H. and Kurman, M., 2013. Fabricated: The new world of 3D printing. John Wiley &
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