The 3D Printing Footwear Take-Over

3D printing

Traditionally, shoes are manufactured using a myriad of cutout patterns for the upper plus a sole comprised of two or three layers. Constructing an upper and fitting it to a last is largely a manual process, making it labor-intensive and time-consuming. Soles are produced with expensive molds for each size, driving up the cost of a shoe. 3D printing offers the opportunity to create shoes in a largely automated way, in a more cost-effective way for limited series of 100-400 pairs of each size, and custom-made for each wearer improving aesthetics and comfort. We are investigating the possibilities of constructing a modern shoe entirely through 3D printing techniques.

In constructing such shoes through 3D printing, several functional and ergonomic requirements have to be taken into account:

  • Airflow providing ventilation to the foot.
  • From the eyestay that holds the lace openings to the sole, there is a large tensile force occurring upon landing of the foot that will need to be absorbed by the structure of the shoe. We can take inspiration from many current shoes where the quarter panel is reinforced with heatbonded films, wires, leather, TPE, or thicker knit structures.
  • Many current shoes have a heel notch: a cutout at the top of the heel to keep the achilles heel from rubbing against the shoe. The upper part of the heel touching the achilles is often cushioned to provide better support. This is a critical area in all-knit uppers as they wrap more tightly around the foot and can cause heel chafing.
  • Multimaterial 3D printing allows for a mixture of materials in various parts of the shoe to give rise to a graded functionality to meet the desired mechanical properties in every part of the shoe. For example, harder materials could be used in the heel in a lattice structure to give rise to the same compressive properties while reducing weight.
  • Grassroots innovation. A very enthousiastic 3D printing community is emerging that is developing more and more skills and knowledge of 3D modeling and product development. Production is on-demand and does not require any stock keeping. This way, a product is always in development as customers are sharing experiences, and work on improvements which can give the product a distinct advantage. These improvements can include compartments for electronics like GPS tracker chips and batteries that are being upgraded over time.
  • Scan data of the customer’s foot will have to be translated into a set of parameters to drive the 3D model customization algorithm.

Construction: FDM

With rapid innovation in available materials, as well as much lower production costs compared to other 3D printing techniques and the capability of using multiple materials on some machines, Fused Deposition Modeling (FDM) is the most interesting technique for 3D printing running shoes. Materials are extruded from a spool or container and laid down in strands layer upon layer. This way, an entire running shoe including sole and upper can be built in one print run with hardly any manual labor needed.
A drawback of this method is that layer-to-layer adhesion tends to be weak, though in some materials it is strong enough to be able to produce functional shoes. These are elastic materials that increase linearly in hardness with the amount of infill printed.

TPE
The most interesting elastic filament for commercial purposes is Flexismart because of its price ($33/kg), color availability and good elastic and tensile properties. The surface is relatively hard so to improve wearing comfort on the inside you could use a flocking gun to apply nylon, rayon or suede fabric fibers.

Filaflex is a more proven filament for footwear applications with a higher price at $85/kg and availability in many striking colors. Its properties can be altered by varying the additives used. Future research is in full motion and includes scented polymers. It can be printed multiple times faster than other flexible filaments because of its low viscosity so up to two pairs a day can be printed with a 1.0 mm nozzle. It is stretchy, softer to the touch than Flexismart and comes in two diameter sizes. Also it has been tested to be food safe, resistant to oils and acetone, non-toxic and non-irritable to the skin. Footwear design school SLEM and several startups are currently printing with Filaflex.

Ninjaflex is a more elastic and less expensive TPU than Filaflex but also weaker – it will be stretched irreversibly at 65% elongation. It is also harder (85 shore A). It can be used to print shoes and insoles in dozens of interesting colors but is mechanically less suitable than Filaflex. Also it has no UV stabilizer so it will start to degrade after 4-6 months of outdoor use. Ninjaflex comes in spools of 1.1 or 5 pound spools at 1.75 or 3 mm at $76/kg.

Recently, a bio-compostable elastic filament has been developed called Willowflex. It comes in two diameters with a cost of $110/kg and requires slow printing speeds. It is strong, has good adhesion between layers and has been proven for footwear applications by professional institutions.

The FlexMark series filaments by TreeD come in shore A 70, 81A, and 93A with a 750% elongation at break and 1.75mm diameter. That makes them softer and more elastic than Filaflex. Disadvantages are that they are supplied in black only and costs $266/kg.

Flexfill 92A by Fillamentum, at $77/kg, comes in 1.75 and 3mm filament and 7 colors. It is a bit less flexible than Filaflex but also elastic with 600% elongation at break property, and very good against abrasion. Unlike Filaflex, this material should be printed slower and with a hot bed.

An experimental material that can prove useful is Rubberlay Solay. This newly developed filament is flexible and elastic with a 90 shore A hardness and costs $160/kg. It has hardly been used but may prove a viable alternative to TPUs. It has a pleasant rough finish and can be dyed in any color.

Another alternative elastic filament is flexible Polyester (FPE) which at a hardness of 90 shore A is suited for shoe soles and cost-effective at $49/kg.

TPE Printers

Most interesting is to use the Lulzbot TAZ 4 printer with multiple printheads to combine softer filaments like Filaflex or Flexismart and harder filaments like Ninjaflex for parts needing more stability or reinforcement. This is a machine from a trusted brand at a price of $1050, including a heated bed, large build volume of 298 x 275 x 250 mm which allows for printing a pair of size 12 sneakers, and the capacity for a dual extruder. It uses 3mm filament and is suited for Ninjaflex and Filaflex.

For printing in a single material, we recommend the Witbox 2 printer, that has been proven to print well with Filaflex. It costs $1,500 and with a build volume of 297 x 210 x 200 mm it enables you to print up to two size 12 shoes simultaneously.

The Lewihe Sneaker printer with Filaflex is the choice for fast printing. Because of its print head adapted to flexible materials, it can print much faster than other FDM printers – speeds up to 140mm/s have been used successfully. Printing a shoe will take about 5 hours. With a build volume of 320 x 185 x 160mm it suits sneakers up to size 15. The machine is priced at $2,995 and uses 1.75mm filament. The XL version is twice the price and its larger build volume allows you to print five sneakers instead of two per cycle. However more production-efficient, due to possible printing errors and not having to replace spools, going for the smallest possible print bed will be more advantageous. You may opt to design a clean break between the sole and upper part, program the machine to pause the print at the parting line and refill the machine with a new filament to create a dual-material duotone shoe. Also you can make a monomaterial shoe much more interesting with hydrographic printing.

The Stacker S4 is the only FDM printer that can print with four materials so allows using a tough material for the sole, a soft flexible for the insole and upper, and a hard material for the stabilizers and eyelets, in a single print. With three or four materials used it can print one shoe per print run, when a single material is used it can use the four heads to print four shoes simultaneously and with two heads it can print one dual-material pair of shoes per cycle. The Stacker S4 works with 1.75mm filament and has a heated bed.

The Fusion3 F306 3D printer is priced at $4,000 and with a dual extruder it allows for the creation of three sneakers up to size 14 in one print run. It is compatible with 1.75mm filaments and has a build volume of 306 x 306 x 306 mm.

Silicone
Next to printing with TPE and TPU polymers, it has recently also become possible to use RTV silicone with paste extruders such as the Hyrel 16A. UV-cured silicones are suited because while they are a paste-like liquid, they can be cured within seconds with UV light. Silicone offers the advantages of a softer feel, lower cost, and provides more grip while being less durable and requiring lower print speeds than TPU. Another disadvantage is lower surface smoothness, because when printed the material is gooey. Recommended is to print largely flat structures without overhangs, and fold these into shape. The Hyrel printer works with multiple 60cc syringes that need to be refilled during printing for large objects. It can also work with various 1.75mm filaments. At a price of $11,000 it has a build volume that allows the printing of eight sneakers simultaneously.

A company to watch in the future is Wacker AG, who have set up the ACEO lab dedicated to developing 3D printers for silicone. In October 2016 their first model, the ACEO Imagine Serie K, is being demonstrated. Another interesting 3D printer for silicone is the SiO-Shaping 1601 developed by Sterne Elastomere. This machine creates detailed prints in silicone in the range of 30-60 Shore A that can be opaque, translucent or phosphorescent and will be released at the K2016 trade fair. With a print volume of 250 x 200 x 100 it can print a single shoe up to size US 11.5 in a single print run.

Resins
Resins such as created with SLA and Polyjet modeling produce very high surface quality but are less abrasion resistant, can be irritating to the skin and degrade over time with UV exposure so therefore are unsuited for outdoor use.

Construction: SLS

With Selective Laser Sintering, powder-based materials are fed into a building volume, and layer-by-layer these particles are fused with high-power lasers. Unlike with FDM, no support structures are needed, and the direction perpendicular to the layers is the strongest so it is best to print shoes upright. Because of superior part strength, an entire shoe could be created in one print run.

3D SLS Printers
The most interesting SLS printer currently available for shoes is the Prodways Promaker P1000. It sells for $115,000 and with a build volume of 300mm cubed and speed of 0.6L/hour it is good for printing 6 pairs in about 6 hours. A drawback is wearing comfort because the material is stiffer so you may have to incorporate a separate inner layer. You can also use rubber dipping to provide a softer outer layer.

The EOS Formiga P110 is priced at $170,000 and allows for the creation of 2 pairs per print run, or 4 pairs for small size shoes.

The 3D Systems SPro 60 is steeper in price at $300,000 and allows for the printing of 8 pairs per print run.

SLS Materials

Two flexible materials are currently available for SLS 3D Printing:

1. TPU. There are a few suppliers that sell TPU in powder form, such as Luvosint with a 92 shore A TPU, also used in the Under Armour Architech shoe. Prodways sells a 70 shore A TPU. Adsint 90A GB30 powder is another soft TPU. These materials have very good abrasion resistance and are very durable with 350-400% elongation before it breaks. These sintered materials are very tough and not very elastic, though lightweight open structures can be produced with tendons and walls of 0.7mm diameter/thickness that can be made elastic by implementing latticework patterns comprised of elements that behave like springs. SLS TPU comes in basic colors and can be further imbued with fabric dyes. The pricing is around $ 200/kg so it will be around $ 80/pair production costs.

2. Duraform Flex. This is a rubber-like material produced by 3D Systems with comparative tensile strength to TPU. It has the added advantage that with added agents it can be produced to a range of hardnesses between 45 and 80 shore A. It is good against abrasion but not as much as TPU, and has only 151% elongation at break.

Construction: Hybrid

The optimal material for a shoe upper is a fabric for its tight fit to the foot, wearing comfort and breathability. It would require an innovative construction to 3D print the shoe this way though there are currently some possibilities. The strategy will be to create a textile-like pattern as a flat surface that can then be formed into a sock-like upper and connected to the sole. This will require the flexibility of a textile structure, the best example being a four-way stretch knit. The advantage of creating an upper from a flat pattern is that each layer comprises the entire pattern, so there are no layer seams crossing the structure as you would have with printing the shoe in three dimensions. That makes the shoe much stronger.

3D Printed Knit
In 2014, a knitting machine was developed that takes digital files as input in the OpenKnit project. Essentially this is a 3D printer for knitted fabrics constrained to tubular knits with up to 3 yarns such as sweaters, hats, scarves and socks. The open-source initiative has had immense success, and allows people to build their own knitting machine with 3D printed parts and components within 5 hours assembly and within reasonable budget. The only human labor required is to attached weights to each print and finish the open edges manually after printing. The printer did not prove reliable enough for repeatedly producing wearable products but is currently continued as Kniterate.com which may result in a very suitable machine.

Continuous Fiber extrusion Disney has developed a 3D printer that extrudes thick fabric thread and with a felting needle creates connections between layers, creating a three-dimensional fabric structure. However this machine is not commercially available and the structures are too fragile for extended use.

Markforged printers extrude continuous fibers at the core of a polymer filament. It will be possible to print yarns together with flexible filaments, creating strong fabric structures, though at the current time these printers are geared towards printing stiff composites using carbon fiber, fiberglass and Kevlar.

Japanese researchers (Matsuzaki et al.) have proved that it is possible to co-extrude textile yarn with PLA on a regular FDM 3D printer with some modifications to the extruder. A jute yarn sheathed with PLA proved to be significantly stronger than unreinforced PLA. Moreover, this method allows for the creation of fabric webs using 3D printers that will have significant mechanical advantages over polymer structures. Elasticity and strength can be controlled by incorporating stretchable yarns into elastic filament for creating a running shoe upper. The printer can be paused at certain points for replacing yarn and /or filament and an automatic cutting system can be developed to cut off the yarn when the nozzle needs to move to a different area.

To directly secure the fabric upper to the 3D printed sole, I recommend using a heat press with heatactivated adhesive with an activation temperature of 100-130 degrees Celsius, such as Heatnbond. I also suggest reinforcing the sides of the shoe by running stronger bands of fabric over the foot from one side to the other, or creating an adjustable strap connected to the sole that can be tightened on top of the foot which will also be a distinctive design feature.

3D Design Apps

1. Rhinoceros + Grasshopper with Lunchbox and Weaverbird plug-ins. A low-priced ($995) professional package with a plugin to create models that change dynamically based on input parameters. Because of the visual approach to generative design it is relatively fast to learn. I recommend setting up a last model with curves, then using Grasshopper to draw geometry for the upper onto the last. For the sole, I recommend to produce this entirely in Grasshopper. The output from Grasshopper are meshes that can be directly exported to a 3D printable format.

2. Solidworks. The modeling approach is to set up a surface model and alter this driven by sketches. Models are parametric so sketches, dimensions and features can easily be changed and the entire model will be recomputed accordingly. The dimensions can be driven by an external design table such as an Excel sheet. The program is quite expensive at around $3,995. Models can be exported to almost any 3D format.

3. Geomagic Freeform. This application allows for a sculptural approach to shoe design which brings the advantage of an intuitive user interface. Reasonably priced at $1,000, it is used by major brands such as Converse, Reebok, Adidas and New Balance to design uppers as well as sole models for mold tooling. With the PHANToM haptic interface, modeling becomes even more intuitive as it gives you the experience of directly working on the surface. Using Geomagic Wrap, scan data of a foot can be imported so the model can be tailored accordingly.

4. Autodesk Within. This allows the creation of complex parametric structures unique to 3D printing. Unlike the easier visual flowchart-based interface of Grasshopper, this program requires deeper level programming.

5. iCad 3D Plus. Relatively easy to use software creates 3D models from 2D drawings by wrapping them around a virtual last. It is targeted to footwear designers so makes for an easy workflow. The designs as well as the last can continuously be altered and output to IGES format as well as 3D printable STL file. In case you are only modeling a sole there is the Sole3D application

 

Mesh Editing Tools

When outputting a 3D file from a 3D design program, it often contains holes and imperfections making it unsuitable to 3D print. This is why you need a mesh editing program.

1. Materialise Magics. Very versatile program to edit meshes and powerful auto-repair and manual repair functions. It also has cut, boolean, retriangulation, smoothing and hollowing functions.

2. Netfabb. Free and easy to use mesh checking and repair software. Especially the wall thickness checker is useful.

3. Meshlab. Free mesh checking and repair software with many advanced features and file conversion options.

4. Meshmixer. Easy to use mesh editing tool with the advanced remeshing functions as well as the possibility to sculpt.

Slicers

To get the mesh file to 3D print well, it has to be converted into gcode including settings for bed adhesion and support structure. Because the possibilities vary across different slicers, it is necessary to carefully select one.

1. Kisslicer 1.5 beta has the best support structures for shoe design. It allows you to peel the supports off as if peeling an orange.

2. Craftware slicer allows for custom support structures.

3. Cura 2.3. Free, fast and reliable slicing software with many customizable settings as well as custom Gcode plugins for altering printing paths, different settings at different print heights, the possibility to write your own dedicated plugins etc. Especially the zigzag support structure is recommended because it peels off easily.

4. Simplify3D. Popular comprehensive slicer package priced at $150.

Online services

1. 3D Hubs – a hub will charge around $150-200 for printing a pair of shoes in flexible filament. Some hubs print in SLS for example My3DPart – it will be several times more expensive but the shoe can be designed 25-50% lighter.

2. iMakr. They have a large variety of 3D printers available and also have printers for rent.

3. i.Materialise, SLS printing in 92 Shore A TPU. This material feels quite rough to the touch so will need some post-production work to improve wearing comfort. Cost of a pair of shoes will be around $1,300.

4. Shapeways, SLS in elasto plastic which is comparable to i.Materialize’s TPU though a bit stiffer. It can be colored with the use of fabric dyes. Cost of a pair of shoes will be around $1,150.

References

  1. 3Dhubs 3D printing community. http://www.3dhubs.com
  2. Benedict (2016) http://www.3ders.org/articles/20161025-sterne-elastomere-launches-sioshaping-1601-silicone-3d-printer-targets-medical-device-sector.html. Last accessed October 26th, 2016.
  3. Designboom (2015). Adidas and Parley launch 3D printed shoe made from collected ocean plastic waste. http://www.designboom.com/design/adidas-parley-3d-printed-ocean-plasticshoe-12-10-2015/ Last accessed October 26th, 2016.
  4. Engadget (2016). Reebok Liquid Speed shoes use 3D drawing for a better fit. October 26th, 2016.  https://www.engadget.com/2016/10/21/reebok-liquid-speed-3d-drawing/
  5. Feetz. http://feetz.com/collections/feetz-firsts-collection
  6. Kooser, A. (2014) Awww. Look what Disney Research 3D-printed. https://www.cnet.com/news/disney-research-3d-prints-cuddly-teddy-bears/. Last accessed October 26th, 2016.
  7. Krassenstein, B. (2015). SOLS Unveils ADAPTIV, 3D Printed Robotic Adaptable High-tops https://3dprint.com/44772/sols-adaptiv-3d-print/. Last accessed October 26th, 2016.
  8. Matsuzaki, R. et al. (2016). Three-dimensional printing of continuous-fiber composites by innozzle impregnation. Scientific Reports 6:23058.
    With all the structure and support knitted in, the Nike Flyknit Racer’s upper and tongue weigh just 34 grams (1.2 ounces). The whole shoe weighs a mere 160g (5.6 ounces) for a size 9, which is 19% lighter than the Nike Zoom Streak 3, a shoe worn by first, second and third place athletes in the men’s marathon at the 2011 World Championships (http://www.dezeen.com/2012/02/22/flyknit-running-footwear-by-nike/) Last accessed September 15th, 2016
  9. Scott, C. (2016) SLEM and BioInspiration Develop Compostable Shoes 3D Printed with WillowFlex. https://3dprint.com/150715/bioinspiration-willowflex-slem/ Last accessed October 26th, 2016.
  10. Yarwindran, M. et al. (2016) THERMOPLASTIC ELASTOMER INFILL PATTERN IMPACT ON MECHANICAL PROPERTIES 3D PRINTED CUSTOMIZED ORTHOTIC INSOLE. ARPN Journal of Engineering and Applied Sciences Vol. 11, No. 10. Asian Research Publishing Network (ARPN).
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Getting On the Move with a 3D Printer

3D printing

dualprint2

The previous article, “3D PRINTING: WHAT IS IT ACTUALLY GOOD FOR?” advised you about how to enable 3D printing to start projects and businesses. This next article is about choosing a 3D printer and getting it up and running. There are now hundreds of brands on the market, quality varies dramatically and installations are not a simple matter of plug-n-play. There are only a few printer brands that have the right experience, customer-oriented approach and know-how to get the fundamentals of the machine in order. So with the guidelines in this article I am pleased to inform you, 3D printing enthusiasts and professionals, about purchasing a new 3D printer for use at home and non-industrial workplaces like offices, studios and schools.

We are only treating FFF (Fused Filament Fabrication) printers here, for the following reasons:

  • Some SLA printers are affordable but while they have great accuracy, the shelf life of materials is limited, materials are up to four times more expensive per unit of volume, materials are toxic and/or irritant to the human body. Also these printers use resins that are not suitable for testing mechanical properties often desired in end-use products. These are mostly used for showcase and mother models for secondary processes such as molding or casting.
  • SLS printers are still too expensive with small build volumes, and require an industrial environment.
  • FDM systems such as Stratasys Dimension are in the lower range of professional printers but too large for in the house, with materials being up to six times more expensive.
  • FFF systems are the only ones with a lot of materials available, a lot of them moreover are open-source with a large community base.

The following factors are most important when considering a 3D printer today:

  1. Dimensional Accuracy. Cartesian printers are generally more accurate than the Delta, Scara and Polar systems. A Cartesian 3D printer separates movements of the X, Y and Z dimension so its position can always be controlled. It does so by having three linear rods bearing the print head. A Delta printer nears the target position through three rods that triangulate each coordinate. A Scara printer is a robotic arm that handles movements in the XY plane, and a Polar printer has a rotating XY printbed with the nozzle moving only upwards. High accuracy is paramount because with vibrations above a certain level this will become visible in the print as a Zebra effect. You can somewhat programmatically control this with firmware settings such as XY-jerk and maximum acceleration. Also the belts of the 3D printer are important and while most are good quality, GT2 belts for example are better than standard ones. Make sure the belts are so tight you can stretch them less than one centimeter up or down. You can buy simple torsion springs to adjust belt tension. Some 3D printers have a moving printhead with integrated direct drive filament feeding system, that can influence print quality because of its inertia.
  2. Electronics quality. Controller boards often fail and the best ones come from Europe and the US and are brand-specific. If you have a generic non-EU or non-US board, it is much more likely to fail. Pay attention to the boards having a variable resistor for adjusting the voltage going to the motors.
  3. Steady extrusion. If your printer does not have a reliable extruder, it will require a lot of maintenance. Some extruders leak if not assembled perfectly, some work only for one type of material, others simply do not transfer enough force onto the filament or have too much cumulative friction along the feeder system. While some companies manage to have a well working Bowden tube system, I recommend a direct drive system, especially if you are working with flexible materials.
  4. Multiple extruders. The ability to print with multiple materials is a desirable capacity both for hobbyists, artists and professionals. The thing with multiple FFF extruders though, is that while one extruder is printing, the other one will have some material still running out and still being in contact with the print. That makes a dual extrusion print of less quality than a single extrusion print. Some printers have solved this using a single nozzle and exchange system. This solution requires an exchange tower where the mixed filament gets deposited before starting with clean material on the print. The thing is that, before the nozzle would be completely clean it would require quite a bit of wasted material slowing down the print. Also, filaments have a sweet spot when it comes to temperature so this can only be used on filaments of the same brand. Keep in mind that while most 3D printers use 1.75mm filament, other use the 2.85 or 3.00 mm filament standards. To gain a quick level of expertise I recommend to stay with one brand and choose for one standard to maintain a single inventory.
  5. Build quality. Like a human body, a 3D printer is a quite complex machine with several sub-assemblies coordinated together. A build can appear healthy, but if there are issues underneath the skin these can manifest rapidly or slowly over time. In order to keep it healthy, you need to preventively maintain it by lubricating the rods and axes as well as the Bowden tube, keep the print bed calibrated and as clean as you can, maintain the PCB heat sinks and wires, tighten all belts and screws, and remove rests of filament in the area. Also keep filament dust and moisture free and stored dry. If you buy a printer, check all components for long-term stability. The best printers will make for a good working life of five years or 5,000 running hours. Plastic components, except for acrylic, will slowly disintegrate and as with wood, start bending and distorting. Composite and steel components will be very stable over time so they are worth investing in. Next to a 3D printer you will need basic tools: a pair of tweezers, allen keys, screw drivers, sewing machine oil, blue tape, 600 grit sandpaper, a steel wire brush for cleaning the nozzle, MEK, Magnalube for Z-screws, and a thin palette knife for removing prints.

Top 10 FFF 3D printers

  1. Artist’s choice: Ultimaker 3
    The printing quality of the UM3 is unrivaled and this being the third machine, the Dutch engineers have further perfected the extruder system. It has a 8 inch cubed build size and the only perfectly working dual extruder system with interchangeable heads that retract when the other is printing. Also electronics are of great quality with open-source firmware. This is the only printer that can produce objects that are nearly smooth enough for artistic display. It comes with a pricetag of over $3,500.
  2. Designer’s choice: BCN3D Sigma
    A great quality dual-head printer. You can consider it the UM3’s little brother, except for the 8 x 12 x 8″ build size, at a lower pricetag and less features.
  3. Engineer’s choice: Wanhao Duplicator s5 Mini
    Wanhao is the only Chinese brand that has created a great reputation and a separate USA based office. After the success of the Duplicator i3, the s5 comes with a build volume larger than that of the UM3 and Sigma, and great quality prints, with a price multiple times lower and higher possible printing speeds. If time-effectiveness is of prime importance, I recommend using multiple Wanhao machines over all other printers. You can adjust printing properties like speed, cooling and temperature on the fly. The downsides of these machines are that some need minor modifications, plus with proprietary software it can take a while to start printing. Nozzles are brand-specific and there is less online community and support than with the other brands. The extended version comes with a price tag but lets you create objects up to 600mm in height, making it ideal for architects and engineers.
  4. Maker’s choice: Snapmaker
    Having been the most successful 3D printing crowdfunded campaign so far, this compact printing partner has yet to prove its mark within the 3D printing space. For a sub $500 price it is a steal given that it has interchangeable heads for CNC milling and laser engraving. With specific software it will also be the most plug-and-play of all printers.
  5. Tinkerer’s choice: Velleman K8200 / 3Drag
    This is the machine if you want to experiment with everything a 3D printer can do. It is fully open-source, software that lets you adjust settings while printing, and with an aluminum frame open build with standard components. This lets you transform the printer for low-budget and time investment into for example a food printer, laser engraver or CNC machine. It is fairly easy to control, has a good direct drive extrusion system and therefore very suitable for educational purposes. The BCN3D+ is a slightly better quality but similar type printer at a higher price tag.
  6. Desk rat’s choice: Wanhao Duplicator i3
    For the 8” cubed build volume and quality you get, this is the best value-for-money printer.
  7. Prosumer’s choice: Flashforge Creator Pro
    The FFCP is a great and reliable machine for the beginning 3D printing enthusiast. With a dual extruder, 9” x 6” x 6” build size and 1.75mm filament it is good for numerous applications.
  8. Beast’s choice: Stacker S4
    The truly good way to do multimaterial prints is to employ at least three printheads: two for the dual materials and one for support. The Stacker S4 with a 14” x 20” build plate lets you use up to four heads in one print so you can make a dual-color product with flexible and soft touch features, faster infill if you use a wide nozzle for the second extruder, as well as perfect smoothness with dissolvable support structures.
  9. Innovator’s choice: Symme3D Original+
    Symme3D is a promising startup and has won several international prizes already. Their Delta machines come in different sizes and are customizable in features, supporting multiple extruders, CNC milling, laser engraving, and multiple filament sizes.
  10. Traveller’s choice: Lewihe Play
    If you are purely getting into 3D printing out of curiosity, have little budget and little requirements for your printing projects, this is the machine for you at $69 cost price and 4 inch cubed build volume.

 

About the author: Ralph Zoontjens (1984) is a product designer with a Master’s degree in Industrial Design and 5+ years of studio and startup experience, mostly related to 3D printing.

3D Printing: What is it actually good for?

3D printing

We are in the middle of a 3D printing hype, with technologies, materials and platforms becoming more and more accessible and affordable in order to spread the technology into studios, offices, schools and homes all around the globe. As appealing as it may seem to invest in a 3D printer, now is the time to take a critical look at 3D printing and evaluate what its true value can be and what we truly need it for.

3D printing is an additive manufacturing technique, constructing three-dimensional objects layer-by-layer. These are some inherent pros and cons vs. other manufacturing techniques:

Additive Subtractive
(CNC, cutting, lathing etc.)
Mold-based
(injection / vacuum / rotation / blow molding)
Craft
Part complexity ++ 0 – – ++
Surface finish – – ++ ++ ++
Lead time ++ + 0
Build time small object 0 ++
Build time large object – – – – ++ – – –
Available materials – – ++ + ++
Fixed costs per product ++ + +
Durability – – + + ++
DIY suitability + 0 1 ++
Batch suitability – – ++ – –

There are various processes to 3D print objects, the most important ones being:

  • FFF (Fused Filament Fabrication) / FDM (Fused Deposition Modeling where a strand of material is released onto a building platform and partially fuses together with the already deposited material. This technology enables low-power and low-budget solutions so anyone can start 3D printing for a few hundred dollars. There are plenty of resources and materials available to print a plethora of objects. How about your own cookie cutters, glow-in-the-dark personalized wall hooks, or wooden sculptures? The most important downsides of this technology are part strength, surface quality and print deformations/failures since prints are constructed in the air from a print bed upwards and therefore are vulnerable to influences such as support structure, bed adhesion, fluctuations in room temperature and ventilation as well as in the flow of material. Also prints can take much longer than expected and operating and maintaining the machine is not as straightforward as it may seem.
  • SLS (Selective Laser Sintering) / SLM (Selective Laser Melting) / EBM (Electron Beam Melting) where a laser successively melts precisely targeted areas in layers of a powder bed. This is good for creating strong parts with complex geometries, thin walls and a nice surface finish. Part deformations are minimal since the printed objects are supported by the surrounding powder. Materials range from metals, engineering plastics, flexible materials and ceramics. These machines cost many thousands of dollars, the cheapest ones coming at $10k, they are mostly used by engineering firms and online 3D printing fulfilment services.
  • SLA (Stereolithography) printers transform liquid resin into solids using light. Imagine a pool being filled in steps, and after each step a part of the liquid inside is hardened by a light from above.The unique advantages are precise and strong parts with an excellent surface finish and low-power operation. Objects need to remain connected to the bottom of the pool so freehanging parts are not possible. Also the material is expensive, limited in range and liquid so not as suitable for home use as compared to FFF.

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An excellent article was recently published on the Toptal engineering blog (1), offering a critical look at the potential of 3D printing for developers. The author makes a good point:

3D printing is not going mainstream any time soon, if at all. The technology is immature, build speed remains slow, part quality is unregulated, aesthetics hardly curated, and there are only a few niches of applications that offer significant value to have customers invest in the technology. As far as home printing goes, it is mostly for the hobbyist who does it out of a love for his or her craft.

The following niches are where the true value of 3D printing lies:

  • Multi-material objects such as gradual transitions in flexibility, complex composite parts, and the integration of conductive materials to create electronic components and PCB prototypes. For example, for the Ara project Google partnered with 3D Systems to integrate conductive components into the phone housing.
  • Small-batch manufacturing of up to 1,000 pieces may prove competitive in price and lead time compared to other manufacturing processes. It is recommendable to use an online fulfillment service since they will offer economy of scale, good quality, better lead time when compared to using a non-professional 3D printer and developers have the ability to integrate an API into their website so as to automate the order and delivery process.
  • Intelligent geometries which save weight and enable part count reduction. An example is GE’s titanium fuel injection nozzle for its next generation CFM LEAP turbofan engine. 3D printing allowed it to be constructed 25 percent lighter and 1 piece instead of an assembly of 18 parts, making a 5 times more durable part.
  • Tailoring of clothing, sports equipment and medical parts such as prostheses, joints and training models.
  • Customized goods such as modular toys derived from computer games and movies, jewelry, fashion and household appliances. See (2) for a more in-depth study.
  • Art. 3D printing affords unique geometries to render any object, be it fashion, furniture or food, into a reproducible work that can be sold as art. There are opportunities for online platforms, that instead of offering an enormous quantity of unchallenged objects, pursue a highly curated approach with only a select number of submitted objects, after careful review and testing, make it to online status.
  • Replacement parts. For example, for NASA, having 3D printers on-board to replace malfunctioning parts can prove critical.

If you are considering investing in 3D printing, my advice is:

If you want to invest in a home-based 3D printer, have a specific long-term plan for it. Even 3D printing simple objects may prove not very easy since you will have to learn a lot about the machine you are working with. This is a manufacturing machine more so than a consumer appliance like your inkjet printer. Also the material is better compared to a porous wood than to a molded plastic. The quality of available items is not regulated so it may not be safe, durable, usable or printable at all. The ratio of failed prints is very high so for some items you may have to tweak and reprint a dozen times. If you have to modify or create 3D models, you will need to learn to use various software programs that require users to practice for months. So if you are only thinking of occasionally printing something, use an online service or contact a local designer.

If you are a school, minimize the amount of 3D printers you invest in and go for quality and versatility. A 3D printer in every classroom is not necessary. If you are considering purchasing several small 3D printers, instead consider to buy one large 3D printer with multi-material option, more durable construction and better build time and quality. It is better to have one 3D printer in a central workshop location since then one person can be assigned to handle and maintain the machine, students will learn to make best use of it and plan their creative endeavors well because of its scarce availability, and no waste products will enter the classrooms. For printing educative objects 3D printing is excellent, but it can also be done on a single printer during the weekends or holidays or done by an external service or your local designer.

If you are an entrepreneur developing your own product, be prepared for the necessity have several prototypes created, in some cases hundreds, before a satisfactory quality is reached. If there are significant challenges in your product design process, be it mechanical or visual (such as in transportation, product and character design), it will in many cases be worth investing in a 3D printer since every physical prototype is worth much more than a sketch to serve as a tool for discussion. Instead of having your designer send the prototypes to you, it is of great value to be able to print the same model as your designer at the same time and discuss it the next day.

If you are a designer, I recommend you to invest in a 3D printer since it will enrich your practice and allow you to do some prototyping. Even if it is a limited amount of prototyping, it will give you more insight into your own work if you can make your results tangible. In most fields, such as toy design, character design, game design, graphic design, industrial or interaction design, there are substantial benefits to integrating a 3D printer into the workflow.

In case you want to use 3D printing to manufacture your products, realize that there are many untapped opportunities as well as challenges where you will need professional developers with experience in design and 3D printing. For most projects I recommend investing in a 3D printer for early prototyping and doing quick tests, since this can provide critical information already early on in the process. I recommend making the step to using the printer to be used for the manufacturing stage early on in the process as well since many iterations may be needed. If you plan to have an online sales platform where products can be customized, I recommend hiring a professional with experience not just in web design, but also in user interaction, experience or interactive product design since online customization adds some extra challenges in development and interface design. You can view customization not just as an addition but as a paradigm change in that you are not selling products, but also the data behind these products, which are to a specific extent accessible, and with that come some fundamental questions about the relationship between your company and your customers.

In conclusion, the main points of this post are that investing in 3D printing is in many cases not what you want to do since the real potential of 3D printing is limited to a very specific range of niches, that within these niches there is a lot of room for further development and unique value to be created, and that this may require the coming together of people from multiple disciplines.

  1. https://www.toptal.com/designers/print/3d-printing-for-developers
  1. Reeves, P. and Mendis, D. (2015). The Current Status and Impact of 3D Printing Within the Industrial Sector: An Analysis of Six Case Studies. The Intellectual Property Office, UK: Newport.
  2. Designsoul. Creative studio specialized in product development and 3D printing.