Design Support

STL data creation

What is STL data?

We are able to work with multiple file formats through our online upload portal and covert to STL for printing. The format that is sent to the printer is STL, therefore we will convert any file given to us in an alternative format before print. If you wish to upload your own STL, simply follow the steps below. STL is a format for storing 3D data, where shapes are represented by tiny triangular flat section (polygons). This simple data format is highly versatile, however care must be taken when converting models to this format from CAD as errors can be created during the translation process. We will be checking for the following errors:

Typical data errors

Data conversion loses detail

Check your STL file settings to ensure detail/accuracy levels are set correctly for your model detail

Surface sections are inverted

The polygonal sections that form the surface have a back and front side. Please use STL software to ensure that all polygons are facing outwards (reverse side shown in red).

The surface has no underlying thickness

There is no surface thickness, surface data alone is insufficient for modelling.

There is a hole in the model

It will be possible to see into the solid section of the model, and print is not possible if there is a gap in the model outline

Wall thickness below the recommended print specification

Please check the information page for each material to ensure the conditions for minimum thickness are met.

Units of measurement

CAD data uses unique units of measurement which work in mm or inches only. After transfer to print, all units of measurement are treated as mm so please use STL software to check your settings are updated. Our engineers will also check size for you

Conversion Accuracy

We are able to accept several files types (3ds, amf, catpart, igs, iges, jt, prt, sat, skp, stp, step, stl), however the format accepted by most 3D printers is STL. Your file will therefore be converted by the RICOH Rapid Fab team using optimum settings, but you may prefer to supply the STL file upfront.

STL files describe only the surface geometry of a three-dimensional object without any representation of colour, texture or other common CAD model attributes.

The STL format approximates the surfaces of a solid model with a number of small triangles.

A simple square object is simple for the STL format to translate and convert into the minimum number of triangles needed to approximate the surface, as shown below.

Consideration has to be given when converting organic-shaped objects into the STL format, as curved features will be translated into small triangles.

When an object with a curved surface is created in native CAD format the geometry represents the design intent. Take a circle for example; when we zoom into the part we can see that the curved surface is smooth, as intended by the designer.

If we compare this to the STL translated file we can see that the surface is very different, as the triangles have approximated the area.

Each native CAD format has STL translation settings that can be optimised for 3D printing. If the settings are too high we end up with too many triangles, resulting in a very large data file. If the settings are too low the triangles will be visible on the object when printed, giving a faceted rather than smooth surface. We recommend specifying a medium resolution to limit the file size, but ensure the STL file represents the intended design.

Each CAD package has different recommended settings for converting files to STL. The RICOH Rapid Fab team can support you in this conversion process, or simply send us your raw data for our engineers to translate the file for you.

stl

Compatible data formats

Parasolid (.x_t)/STEP (.stp)

Parasolid (.x_t) and STEP (.stp) are the formats recommended for data created for computer-aided design in 3D.
If conversion to these two formats is not possible, we can also accept CAD native files created in the CAD listed below or IGES format.
Please contact us for non-designated CAD/file formats (including STL). There may be cases where we cannot accept the order.

List of various CAD file formats

Application CATIA Solidworks NX Creo(Pro/E) Autodesk Inventor® ICAD/SX ICAD/MX
Native file (extension) .CATPart .sldprt .par .prt.∗ .ipt (Not compatible)
Intermediate file Parasolid (.x_t)/STEP (.stp)*1
Manufacturer Dassault Systemes SIEMENS PTC Autodesk iCAD
  1. If both formats are not possible, only IGES will be accepted.

Layer thickness

You can select the required minimum layer thickness from multiple menus for some of the materials that are used in modelling with the FDM method.

Advantages of high definition modelling

The difference, which can be particularly noticeable on curved surfaces, is reduced due to the minimum layer thickness being more subtle. Furthermore, because the line width at the time of modelling is finer, it is easier to reproduce fine detail such as ribs and lettering.
You will also achieve a stronger model with a lower definition setting and higher layer thickness.

Disadvantages of high definition modelling

The price point is higher due to the models taking longer to fabricate.

lamination

Filled structures

There are two types of filled structures inside a model. These are Solid and Semi-hollow for any materials modelled using the FDM method.

Solid structures

The entire model is filled with material. This is recommended when your model has several thin areas, such as parts to be used for injection moulding.

Advantages Disadvantages
You can obtain a model with high strength. The cost of modelling tends to be higher when compared to semi-hollow shapes due to the increased materials used.
Depending on the shape, it may be that the model will distort.

Semi-hollow structures

The inside of the model is a mesh shape (excluding the upper and inner surfaces, and the walls). This is recommended when your model has several thick areas, such as parts to be used for cutting processes.

Advantages Disadvantages
The model will be lightweight.
It can have a lower cost due to a reduction in materials used.
It may be less strong compared with a solid structure.
For parts with several thin areas, there will not be a significant price difference compared with a solid structure.
filled