The 3D printing process involves slicing a 3D model then using a 3D printer to print the model with the selected filament. 3D printing services are available for those who do not have access to their own 3D printer.

Quick link: Return to the 3D printing guidelines overview.

3D printing services

There are many options for 3D printing for those who do not have direct access to a printer.

• Commercial 3D printing services: For example, CraftCloud provides quotes from a global network of providers; Hubs is a high quality service with worldwide professional printing providers; and PrusaPrinters has a community website to connect with individuals who can provide a print-on-demand service. The advantage of these services is that they give choice in terms of the type of printing process, materials and colours. Prints can be ordered online either from their catalogue or by supplying a 3D model file.
• Education departments: Most accessible format production teams within education departments are also able to design, produce and loan 3D printed models for students who are blind or have low vision.
• Schools: Many schools have 3D printers. It may be possible for teachers to use the printer or ask school staff to provide 3D prints for students with print disabilities. It may even be possible to set a class project for students to design and produce 3D models for accessibility.
• Public libraries: Some public libraries have 3D printers available for public use, charging by the hour. Library staff will do the printing based on individual requirements. Check local council websites for availability.
• Blindness agencies: The advantage of ordering through a blindness agency is that they will be able to assist with design and provide advice on the suitability of 3D models for people with print disabilities. In Australia, NextSense provides FDM 3D printing and laser cutting services at cost via NDIS funding. Vision Australia can produce FDM 3D prints and commercial quality UV printed reliefs for their clients or as a commercial product.
• Community groups: See3D is a not-for-profit organisation providing volunteer 3D design and printing for touch readers. They are based in the US but can post to Australia or New Zealand. They are hoping to establish these services with local providers in the future.

3D printers

FDM printers are the most common type of 3D printer for home and school use. As illustrated below, a reel of plastic filament is fed into the print head where it is melted and extruded through a nozzle. The print head can move back and forth and side to side. Either the print bed or print head can also move up and down so that the filament can be extruded one thin layer at a time.

Selecting a 3D printer

When choosing a printer, consider the following factors:

• Printer type: FDM printers are the easiest, cheapest and most commonly used printers in education. SLA printers use resin and can produce models with a finer level of detail, however the end product can be brittle and the production process is messy and more time-consuming, requiring UV curing and clean-up of liquid resin.
• Maximum print size: This is determined by the bed size and printer height. A build size of 20cm³ is sufficient for most hand-held models.
• Bed heating: A heated bed assists with adhesion, which is particularly important if using ABS filament or if printing large models with a flat base.
• Nozzles: A single nozzle is sufficient for most prints, however two nozzles are required for soluble supports or multi-colour prints.
• Filament: 1.75mm filament is the standard size and allows a somewhat wider choice of colours and materials. Some specialist filaments such as those containing metal can only be used with certain printers.
• Location of the filament feeding motor: Select a printer with the filament feeding motor close to the print head (direct feed) if using flexible materials such as TPU or nylon. Direct feed printers are generally also easier to use for people with print disabilities.
• Automation: Some more expensive 3D printers have cameras to monitor a print remotely. They can automatically sense when the filament is blocked or empty, etc. These features are more important for printing very large models or multiple copies overnight.
• Community support for solving printing problems: Online communities, support and troubleshooting are likely to be better for more well-known and established 3D printing companies.
• Accessibility: Consider whether the printer gives audible feedback and whether it can be operated remotely using command lines or an accessible slicer. Further details on 3D printing accessibility are given in our guidelines for Blind makers.

Some printers recommended by the ANZAGG 3D printing group members include Bambu, Prusa and Ultimaker.

3D printing filament and materials

A variety of 3D printing filaments and materials are available. These should be chosen with consideration given to print quality and durability.

• • PLA: A corn-based plastic filament (more environmentally friendly) that prints reliably and is good for fine detail. The melting point is relatively low, so objects printed in PLA are likely to warp in a hot car or hot water. PLA filament should be stored in a plastic bag with desiccant to prevent it from absorbing atmospheric humidity and becoming brittle. Tough PLA is a slightly stronger option for models that must withstand tension or rough treatment. Silk PLA provides a smoother finish that may be more pleasant to the touch.
  • ABS: A plastic filament that is very good for strength and durability. ABS prints at a high temperature (giving off unpleasant fumes) and it can therefore be used as a master for thermoform copies. It is not good for fine detail and adhesion and shrinkage can be problematic during printing. Excellent smoothing can be achieved after printing using an acetone bath (Section 9.1.3 Chemical smoothing), however this process involves handling of hazardous chemicals.
  • PET-G: This filament has the same advantages as PLA (it prints reliably and gives fine detail) but it is stronger and is more resistant to heat.
  • PVA: Filament used to create dissolvable supports with a two-headed printer. After printing, the model can be soaked in water to dissolve and remove the supports, leaving a smoother finish. Beware of moisture absorption during storage and if necessary, place the reel on a hot printer bed to remove any moisture.
  • Conductive filament: Can be used to seamlessly integrate electronic components within a model, providing a connection between a touch point on the model’s surface to electronics underneath or inside the model to allow for features such as audio touch points.
  • TPU and Nylon: These filaments are slightly stretchy and can be used to create “squishy” models, for example for anatomical parts. When printing with TPU and nylon it is best to use a 3D printer with the filament motor near the print head to reduce errors caused by stretching and warping between the motor and the nozzle.

• Carbon fibre filaments: Metal filaments are excellent for strength, stiffness and finish. However, they can only be used with printers that are designed for that purpose (with enclosed printing and higher temperatures), and it is best to use steel printing nozzles.
• Speciality filaments: Filaments containing wood or other materials can be used to give a slightly different texture, feel or smell. However, they can cause printing problems as they tend to clog or abrade nozzles.
• Resin: This material is used with a specialised SLA printer. It is the best option for achieving very fine detail, however a clean-up process and UV curing are required, which can be messy and time-consuming. The cost of materials is significantly higher than most FDM filaments and the finished models can be brittle and break easily.

Slicing

Slicing is the process of setting instructions for the 3D printer on how it should print a model. Printers come with their own slicing software and there are other slicers that can be used with a range of printer brands. The slicing process involves opening a 3D model file in the slicing software, selecting settings such as size, orientation, print quality, etc., then slicing the model to obtain a .gcode file that can be sent to the printer.

Thoughtful slicing is an invaluable step for reducing printer errors and achieving a smooth, touch-friendly finish.

Layer height

Thinner layers have better adhesion to a heated bed and give more fine definition, reducing ridges between layers. However, thinner layers take much longer to print.

Sometimes, thick layers can help convey meaning for the 3D object, such as a model of a striped animal or of a sedimentary landform.

Size

In general, touch readers prefer larger models [19]. Within reason, bigger is better for the user but takes much longer to print and consumes more material. Models should not exceed arm’s length.

Do not resize models with braille labels included on them, as braille must be read at a standard size.

Supports

Supports are additional structures added during slicing to hold up overhanging structures on a 3D model.

Supports are generally needed if the overhang is greater than 45 degrees. They are always needed if a separate part of the model starts above the base, such as the horse’s nose and belly in the figure below.

Tree supports are the recommended type of support structure when printing for touch readers as they are easier to remove and leave less residue.

PVA supports can give a good finish but a two-headed printer is required and the process of dissolving and removing them is messy and time consuming.

Orientation

The orientation or rotational position of a 3D model is important in terms of stability, supports and strength.

Stability: Tall thin models are likely to move during printing, which can cause printing problems such as mis-aligned layers or falling. If possible, orient the model so it has a wide flat base and height is minimised.

Supports: As described in Supports, try to orient the model to minimise overhangs and the need for supports. Also consider printing the model in two parts if it has too many overhangs. Prusa Slicer and its variants have a built-in function to automatically split models and create pegs and peg holes to join the model, while Cura has a banana split plug-in.

Strength: A 3D print is most likely to break along the horizontal printing plane, where the printing layers join. Long parts that need strength should be laid flat, parallel with the printing plate.

Fill

Fill refers to the pattern and amount of 3D printed structure inside a 3D printed model to give it strength. The amount of fill will usually range between 15%-50%.

It is possible to add weight and strength to a model simply by increasing the fill but it also adds to the print time and uses significantly more material.

Lightning fill is a fill pattern available in Cura for very quick printing when strength is not required.

Adhesion

As described below, Adhesion to the build plate is the most important and often difficult requirement for successful 3D printing. Adhesion can be assisted by the addition of filament at the base, selected through the slicer settings. This is most often required when using ABS filament, when the model is very large, or when the model will be printed upright with a small base.

A brim is a thin single layer of filament forming extending the base of the model. After printing, use a deburring tool (available from hardware and 3D printing stores) to remove the brim and achieve a smooth edge.

A raft is a latticework of filament that is printed underneath the model. Rafts can consume a lot of material, add significantly to the printing time and be difficult to remove, but it can be an effective solution when adhesion is particularly problematic.

Printing speed

Slow down the printer for stability when printing a model that might be liable to tipping (tall with a small base).

3D printing and troubleshooting

The 3D printing process involves a lot of moving parts and melted plastic, and is therefore prone to errors. The key to becoming skilled at 3D printing is to take a tinkering approach: look up resources online, use trial and error, and be willing to pull the printer apart. Most 3D printers are designed to be fixable by home users and it is easy to purchase and install replacement parts.

Placement of the printer

3D printers and 3D printing filament are susceptible to errors caused by the environment.

Do not place the 3D printer on the same benchtop as another piece of equipment that is likely to cause vibrations, such as a braille embosser.

Do place the 3D printer in a position where it is protected from air drafts and humidity. If the 3D printer has open sides, it may be necessary to add protective shields from drafts. These can either be homemade hacks or commercial options such as the Wham HotBox.

Adhesion

Adhesion refers to how well the 3D print sticks to the build plate. Good adhesion is required to prevent the 3D models from moving or falling during the printing process, after which time the printer will have nothing to build on and create a “spaghetti” mess of extruded filament strands. There are a number of strategies that can assist in achieving good adhesion.

Levelling the bed: Levelling the bed is the most important step for successful printing. Level the bed after moving the printer and any time that there are problems with adhesion. Use the printer’s automated levelling method then print just the first one or two layers of a large model to check that it sticks without dragging. Make fine adjustments as necessary.

Glue stick: Glass printing plates can benefit from a very thin layer of glue. Smear the plate with a glue stick and then wipe it with a wet paper towel. Alternatively, dissolve a glue stick in water and smear the liquid on the plate. Always let the glue dry before printing. Clean the plate and repeat the process as necessary.

Extrusion

Extrusion refers to the process whereby filament is melted and passed through the nozzle in an FDM 3D printer. Poor extrusion will result in problems with adhesion, 3D models that appear porous with small holes in them, and layers that break. Poor or blocked extrusion can be caused by problems in the print head or the filament feed. The following strategies are effective for identifying and fixing most problems with extrusion.

1. Check the filament reel. Is there sufficient filament on the reel? Has the filament become tangled?
2. Remove the filament using the printer’s feed mechanism. Did the filament come out or was it stuck? If stuck, did the feed motor turn? Has the filament ground down where it is in contact with the feed motor?
3. Heat up the nozzle and then manually remove the filament from the printing head. If there is a blockage inside the nozzle, this can usually be cleaned by sticking a clean piece of filament into the nozzle and pulling it out while the nozzle is still hot. Finally, manually push some filament through the nozzle to ensure that it goes through cleanly.
4. Reload the filament and run some filament through the nozzle using the printer’s automated mechanism to check that everything is working properly.

Stringing

Stringing refers to tiny strings of filament pulled out from the 3D model where the printing head has lifted up and moved from one part of the model to another. Strings can be very sharp, therefore it is important to address this problem when creating 3D models for touch readers.

Stringing may be caused by any of the following issues. More detailed advice for specific printers and slicers is available online.

• Retraction refers to pulling the filament back after each extrusion to prevent it from oozing out as strings or blobs. It is the most effective method for reducing stringing. Retraction can usually be selected as an option in the slicer settings.
• If the temperature setting is too high for the filament, the filament will ooze out and cause stringing.
• A very fast print speed can cause stringing. Conversely, a fast travel speed (between parts of the model) will reduce stringing. These settings can be adjusted in the slicer.
• Cleaning the nozzle is a simple solution that may reduce oozing that was caused by pressure inside a dirty nozzle.
• Swollen filament can likewise cause oozing due to increased pressure. Filaments must be kept in a dry environment because they are hydrophilic and will absorb moisture, causing swelling. If a filament has been exposed to a humid environment, it may be dried by exposure to a warm temperature.

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Last updated: June 3, 2024 at 12:17 pm