Organic Farming | 2015 | Volume 1 | Issue 1 | Pages 19–35
DOI: 10.12924/of2015.01010019
Organic
Farming
Research Article
Applications of Open Source 3-D Printing on Small Farms
Joshua M. Pearce*
Department of Materials Science & Engineering, Michigan Technological University, MI, USA;
E-Mail: pearce@mtu.edu; Tel.: +1 9064871466
Department of Electrical & Computer Engineering, Michigan Technological University, MI, USA
Submitted: 6 January 2015 | In revised form: 27 February 2015 | Accepted: 11 March 2015 |
Published: 16 April 2015
Abstract: There is growing evidence that low-cost open-source 3-D printers can reduce costs by enabling
distributed manufacturing of substitutes for both specialty equipment and conventional mass-manufactured
products. The rate of 3-D printable designs under open licenses is growing exponentially and there are
already hundreds of designs applicable to small-scale organic farming. It has also been hypothesized that
this technology could assist sustainable development in rural communities that rely on small-scale organic
agriculture. To gauge the present utility of open-source 3-D printers in this organic farm context both in
the developed and developing world, this paper reviews the current open-source designs available and
evaluates the ability of low-cost 3-D printers to be effective at reducing the economic costs of farming.
This study limits the evaluation of open-source 3-D printers to only the most-developed fused filament fab-
rication of the bioplastic polylactic acid (PLA). PLA is a strong biodegradable and recyclable thermoplastic
appropriate for a range of representative products, which are grouped into five categories of prints: hand
tools, food processing, animal management, water management and hydroponics. The advantages and
shortcomings of applying 3-D printing to each technology are evaluated. The results show a generalizable
technical viability and economic benefit to adopting open-source 3-D printing for any of the technologies,
although the individual economic impact is highly dependent on needs and frequency of use on a specific
farm. Capital costs of a 3-D printer may be saved from on-farm printing of a single advanced analytical
instrument in a day or replacing hundreds of inexpensive products over a year. In order for the full potential
of open-source 3-D printing to be realized to assist organic farm economic resiliency and self-sufficiency,
future work is outlined in five core areas: designs of 3-D printable objects, 3-D printing materials, 3-D
printers, software and 3-D printable repositories.
Keywords: 3-D printing; agricultural tools; distributed manufacturing; farm equipment; intensive agricul-
ture; small farms
1. Introduction
World wide, the area of organic farmland continues to
increase significantly [1,2]. Approximately a third of the
world’s organically managed land (i.e. 11 million hectares)
is located in developing countries and nearly half of the
world’s organic producers are in Africa [2]. In the devel-
oping world in particular, these farms are owned by rel-
atively resource-poor landholders. However, such small
farms may contribute significantly to agricultural produc-
c
2015 by the authors; licensee Librello, Switzerland. This open access article was published
under a Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0/).
librello
tion, food security, rural poverty reduction and biodiversity
conservation, despite the historic challenges small farm-
ers face in terms of access to both productive resources
and markets [3]. In addition, small farms in the developing
world must overcome new challenges including adapting
to climate change, market volatility and risks and vulnera-
bilities associated with integration into high-value chains
[3–5]. There is some disagreement in the literature as
to whether investments in infrastructure and technical effi-
ciency alone are sufficient to address the negative impacts
of climate change for developing-world farmers [6,7]. Al-
though, it is clear that these challenges can at least in part
be overcome by increasing the profit of organic farming
in the developing world, which in turn is influenced by in-
creasing revenue (e.g. by increasing yields, selling in more
lucrative markets, etc.) or by reducing costs. Many or-
ganic farmers in both the developed and developing world
save money and produce high-quality crops with few or no
off-farm inputs, but most producers rely on at least some
purchased inputs [8]. In addition, those farmers above
the level of poverty subsistence also purchase their own
equipment. As one of the costly inputs for organic agricul-
ture is tools and equipment, this study investigates reduc-
ing farm-related tool costs for organic farms using open-
source 3-D printing. In this way, distributed on-site man-
ufacturing of tools and equipment can aid in organic farm
self-sufficiency.
There is a growing body of evidence that low-cost open-
source 3-D printers [9,10] can reduce costs not only for
high-end products like scientific equipment [11,12], but
also for conventional mass-manufactured consumer goods
[13–16]. There has been an explosion of open-source sci-
entific equipment [12,17–22] and the number of free con-
sumer designs has been rising exponentially [14]. There is
also a body of work proposing that 3-D printers would also
be useful for sustainable development [23–25]. While the
application of 3-D printing in developing countries is still at
an early stage, the technology application promises vast
solutions to existing problems [23,24]. For example, most
small farmers in the developing world use labor-intensive
agricultural hand tools; Ishengoma and Mtaho hypothesize
that superior tools can be developed with 3-D printing im-
proving the efficiency of agriculture in the developing world
[25]. At the same time it appears likely that the cost-saving
nature of distributed manufacturing of 3-D printing could
also benefit developed-world small-scale organic farms.
To gauge the current viability of the utility of open-
source 3-D printers for organic farms both in the developed
and developing world, this paper reviews the current open-
source designs available and evaluates the ability of a low-
cost 3-D printer capable only of fused filament fabrication
(FFF) plastic manufacturing to reduce the cost of small-
scale farming. A range of representative products are
grouped into five categories of prints for review: 1) hand
tools, 2) food processing, 3) animal management, 4) wa-
ter management and 5) hydroponics. The advantages and
shortcomings of each technology are evaluated. Conclu-
sions are drawn on the economic potential of open-source
3-D printing in the organic farming context and future work
is outlined to reach this potential.
2. Methods
2.1. Equipment—MOST Delta RepRap
Following lessons developed in free and open source soft-
ware [26–30], the RepRap project has undergone a rapid
technical evolution and offers the lowest cost 3-D printing
equipment, which is also capable of printing its own re-
placement parts [9,10,14,31,32]. The early RepRaps used
a Cartesian design, however, several RepRap 3-D printers
now use delta robot designs similar to those used for pick
and place in the electronics industry [33]. Delta RepRap
3-D printers have a stationary print bed and an extruder
that moves in all 3 axes. The 3-D printer works by taking
plastic filament into the extruder, melting it and depositing
a 2-D pattern on the substrate. The extruder is then moved
up a fraction of a mm (normally 0.1–0.35 mm) and the next
layer of the 3-D printed object is deposited. The process
repeats until the entire object has been fabricated in solid
plastic. Delta RepRap 3-D printers use standard AC elec-
tricity to run and while printing consume <50 W. In order
to operate effectively this power should not be interrupted,
the results of which will be discussed below.
Although delta 3-D printers are operationally less intu-
itive, they require less time and are easier to assemble, re-
quire fewer parts and have lower capital costs. The MOST
(Michigan Tech Open Sustainability Lab) Delta RepRap
has three linear actuators arranged vertically around a cir-
cle 1. The MOST Delta RepRap costs under $450 in parts
and can be built in approximately eight hours once the bill
of materials (BOM) has been collected by inexperienced
first-time 3-D printers [34,35] (the ability of new users to
build working machines has been demonstrated over 100
times in a number of contexts from college classes to sem-
inars and hack-a-thons). This type of 3-D printer was cho-
sen for this study because of the value—it has low capi-
tal costs for the quality of the prints and the build volume
(250 mm in radius and 270 mm high) provided. In addi-
tion, farmers, who are generally handy at fixing equipment,
would best be served by a 3-D printer they could maintain
themselves. Having access to a machine that they can
take apart, fix, upgrade and try their own modifications on
provides far more value at a significantly lower cost than
a conventional tooling arrangement with warranties that
simply may not be available in all parts of the world. In
addition, such RepRap technology can contribute to farm
self-sufficiency. All of the MOST Delta RepRap design
files, schematics, build instructions and bill of materials are
available on Appropedia for free [34]. The results of this
study are not limited to this particular RepRap, however,
all examples can be printed with it—and most other (full
size) RepRap variants.
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Figure 1. The MOST Delta RepRap 3-D printer. The yel-
low and black polymer components of the 3-D printer have
been printed on the same type of 3-D printer. The glass
hexagon at the base is print substrate.
2.2. Free and Open-Source Software Tool Chain
All of the software necessary to design and operate the
3-D printer is free and open source software that can be
used for free (at no cost). For farmers wishing to minimize
computing costs as well, older low-cost or ’junked’ com-
puters can be recycled into useful machines by installing a
GNU/Linux [36] based operating system, such as Debian
[37]. In addition, open-source computers such as the $35
Raspberry Pi [38] can be attached to recycled peripherals
to operate the 3-D printer.
3-D digital designs can be created by farmers them-
selves or customized from existing designs using Open-
SCAD [39], which is a free and open-source script-based
solid modeling program. OpenSCAD using parametric
variables that automatically manipulate the entire part to
enable simple modifications without the need for a deep
knowledge in 3-D modeling. Farmers that are comfortable
with basic geometry can create complex designs by manip-
ulating primitive shapes (e.g. spheres, cubes, cylinders) in
OpenSCAD, which then generates STL (STereoLithogra-
phy) files of the finished parts, which are in turn sliced with
the open-source Cura [40] before being printed (slicing is
the software process of dividing a 3-D model into print-
able 2-D layers and it plots the toolpaths to fill them in).
Parts that need structural strength are printed solid with
100% infill, while non-critical components can be printed
with lower infill percentages, saving time, energy and plas-
tic costs. Conventional RepRap firmware [41] or the new
open-source Franklin printer firmware [42] was used on
the printer itself and controlled with Printrun (open-source
printer controller) [43].
2.3. Materials—PLA
RepRaps typically print in polylactic acid (PLA) or acryloni-
trile butadiene styrene (ABS) for a wide range of colors. In
this study, PLA will be evaluated as it is a stronger plastic
than ABS; RepRap printed parts have an average tensile
strength of 28.5 MPa for ABS and 56.6 MPa for PLA [44].
PLA is a bio-based plastic, made up of a repeating chain
of lactic acid. It is recyclable using conventional methods.
In addition, PLA can be composted like other organic mat-
ter [45]. When composted, the moisture and heat in the
compost pile break the PLA polymer chains apart, creating
smaller polymer fragments, and finally, lactic acid. How-
ever, abiotic hydrolysis has been shown to be a rate limiting
step in the biodegradation process of PLA and organisms
were not able to accelerate depolymerization significantly
by the action of their enzymes [46]. Both the smaller poly-
mer fragments and lactic acid act as nutrients for microor-
ganisms in the compost. As lactic acid is widely found in
nature, a large number of organisms metabolize it into car-
bon dioxide, water and humus, an important component of
soil fertility [47–50].
2.4. Categorization of Printable Objects
Utilizing the Appropedia wiki (appropedia.org)—is the
largest collaborative site for solutions in sustainability, ap-
propriate technology and poverty reduction—that curates
many 3-D printing designs and Yeggi—a printable 3-D
model search engine for tens of thousands of designs
[51]—a range of 3-D printable objects that may be useful
for organic farmers was identified and reviewed. For eval-
uation in this study, four products or product components
were chosen in each of five categories: 1) hand tools, 2)
food processing, 3) animal management, 4) water man-
agement and 5) hydroponics. The selected prints are sum-
marized with their sources in Table 1. These twenty objects
were chosen based upon i) having free and open source
designs already available, ii) the ability to be printed on a
low-cost MOST Delta RepRap using PLA while preserving
their functionality, iii) having been previously demonstrated
to be useful in farming and gardening (e.g. not models
or toys) and iv) representing a variety of different types of
functions for demonstration purposes. As such this is not a
complete review of every 3-D printable object that may be
useful for organic farmers, nor every object organic farm-
ers may find value in printing, as there are literally thou-
sands of these and the number of free designs is growing
exponentially [14]. Rather, this study provides a survey of
3-D printing applications that represent classes of objects
already designed and a realistic approach of how small-
scale farmers could use available 3-D printers today. Thus,
the objects included in Table 1 may also be useful to the
broader general agriculture community as well.
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