3D printing FAQs

Answers to frequently asked questions about voxeljet 3D printing.

1. Production process and placing an order

How does voxeljet's 3D printing process work?

voxeljet's 3D printing process consists of seven steps:

voxeljet examines the CAD model from an engineering perspective and then prepares it for 3D printing. After the building platform raises the job box to its topmost position, the recoater begins applying the selected particulate material (either plastic or sand) in thin layers onto a build surface. The standard layer thickness is 150 µm for plastic and 300 µm for sand. A high resolution print head then selectively prints binder onto the surface where the parts are to be produced and subsequently bonds this area. After each layer is applied, the building platform is lowered by the particular layer thickness. The recoater applies another layer of particulate material, which is again selectively bonded to the previous layers. The process keeps repeating until the object's desired build height is reached. When the printing process is finished, the excess material is extracted and the component is exposed. In the end, the printed component can be finished, depending on the application purpose.

What file formats can be used?

Generally speaking, voxeljet processes all common file formats but prefers .STL, .STP and .IGS.

What happens to the files?

All files are treated as strictly confidential and are covered by confidentiality agreements. Before the printing process begins, voxeljet reviews each 3D model submitted to rule out any errors. If any irregularities arise, you have the option of either making the corrections yourself or hiring voxeljet's dedicated team to perform this task. On request, voxeljet can also create a mold based on a positive.

How can I get a quote?

Send an inquiry with your wishes and requirements (CAD data, material, quantity, lead time, etc.) to parts@voxeljet.de. Alternatively you can fill out our online form or contact your consultant directly.

Would you like to receive a quote on our 3D printers? If so, send an email to systems@voxeljet.de or contact one of our global resellers.

How do you set the prices for components?

The pricing process is based on the following:

  • Component dimensions
  • Component volume (in plastic only)
  • Complexity
  • Type of material
  • Finishing treatment
  • Number of parts ordered
  • Lead time agreed on

If you have any further questions, do not hesitate to contact us at parts@voxeljet.de.

How are the parts delivered?

voxeljet has years of experience using the appropriate supports, underlays and transportation aids and will work closely with you to find the best way of shipping the parts to their destination. However, should any damage occur, voxeljet will replace your component quickly and smoothly (if the transport was arranged by voxeljet). In principle, you can also pick up the goods yourself.

Do you ship the components worldwide?

Yes, voxeljet delivers models and molds around the world (sand models only by arrangement).

What lead times can I expect and do you offer express shipping?

The lead times are:

3working days*
5working days
10working days
21    calendar days

 The different price categories, among other things, depend on these lead times.

*3-day express shipping is available for sand molds and models by arrangement.

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2. Areas of application and different types of material

What industry segments use this technology?

voxeljet 3D printers are especially suitable for producing molds and metal casting models in small series. In addition, they are also used to develop prototypes.

Our processes are becoming an increasingly popular choice in the production of design samples, art and architectural parts as well as spare parts and individual pieces.

We would be happy to advise you on your particular application. Send your inquiry to parts@voxeljet.de.

 

Materials

Casting3D printing
Magnesium Plastic, including infiltration with wax or epoxy resin
AluminiumKerphalite sand
Iron and steel castingVarious silica sands
Steel casting
Brass casting

 

Branchen

  • Automotive
  • Engineering
  • Aerospace
  • Architecture
  • Research & medicine
  • Film & Entertainment
  • Energy
  • Museums
  • CFRP/GFRP laminating molds

What materials are used in 3D printing?

In principle, two types of plastic can be selected.

Polypor B, available as a voxeljet service and for system customers in Europe, is ideal for parts that are true to detail and which require a high degree of edge sharpness, resolution and green compact strength (degree of hardness immediately at the end of the printing process).

Polypor C lends itself to simplified burn-out processes in investment casting and for all-white architectural models.

The types of sand are chosen individually, depending on the geometry and application purpose. We use silica sands with different granulations. They are available in average granulations of 0.14 mm (GS14); 0.19 mm (GS19) and 0.25 mm (GS25). voxeljet also offers more temperature-resistant kerphalite sand, which is the material of choice for particularly complex geometries and inner cores for steel casting.

Investment or sand casting?

Factors such a:

  • intended application
  • quantity
  • size
  • surface requirements
  • geometry

are basic factors in choosing the right production method. We discuss the most suitable production process with you when we prepare the quote. In general sand casting is the preferred method for progressively larger sizes and quantities.

What are the advantages of voxeljet's plastic models?

  • Can be treated like wax models
  • High surface quality & resolution
  • Low residual ash content around 0.3 wt% for Polypor B binder and around 0.02 wt% for Polypor C binder
  • Minimal expansion during the burn-out process: the ceramic slurries of the 3D models remain undamaged
  • Burn-out temperature 700 °C and higher
  • Can be used in
    •  Ceramic casting
    • Gypsum casting
    • Plaster casting
    • Suitable for all common alloys

What are the advantages of sand molds and cores?

  • Suitable for nearly all metals that can be cast using the sand casting method.
  • voxeljet has experience with
    • Magnesium
    • Aluminum
    • Iron and steel casting
    • Steel casting
    • Brass casting
  • Due to the relatively low binder content, the cores can be easily broken out of the mold after casting.
  • As a result less outgassing of the molds is required (more binder = higher gas discharge).
  • Flexibility:
    • Hybrid casting—can be combined with molds produced with conventional methods
    • The gating can be added manually after 3D printing
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3. Model and mold properties

How complex can the components be?

There are almost no limits in terms of geometry. Undercuts can be added without problems.

Limitations:

  • It must be possible to remove excess particulate materials from the molds and models.
  • A wall thickness of at least 3 mm in sand and 1 mm in plastic must be maintained, depending on the geometry.

Each component is assigned to a certain complexity level. The pricing, among other things, is based on this complexity.

How precise will my component be after printing?

Plastic modelsSand models
Accuracy± 0.4 % (min. ± layer thickness)± 0.1 % (min. ± layer thickness)

What model sizes can be implemented?

voxeljet's service center uses the VX4000, one of the world's largest industrial 3D printers for the production of sand cores and mold packages, with a build space of 4,000 x 2,000 x 1,000 mm (LxWxH). When it comes to plastics, voxeljet offers models with maximum dimensions of 1,000 x 600 x 500 mm (LxWxH). At the same time, molds of any size can be created with the use of individual mold divisions.

What types of finishing treatment options are there?

In the case of sand, you can select between raw material (common), epoxy resin infiltration and PU dispersion. Infiltration makes the component more stable, but it can then no longer be cast. PU dispersion is a special undercoat for the component, which makes it easier to paint the part later on.

In the case of plastic, components can be infiltrated with wax (for investment casting models) or epoxy resin (for design or exhibition models). It is not possible to print pigmented models; however, colors can be applied manually after printing.

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