3D Modeling
For ONEOFF the true raw material is a 3D file from which every technology, material and result is possible.
For each quote ONEOFF requires the 3D file from the client in order to reduce time and costs. If the 3D file is not available ONEOFF offers support in designing and modeling, realizing CAD models from the client’s idea to the project development:
- correcting the available files,
- modeling in three dimensions from 2D drawings or print outs.
We use CAD solid/surface modelers (Rhinoceros 3D, ProEngineer, etc) and *.stl files (Magics).
We accept all file formats from the most commonly used 2D and 3D modeling software.
Requisites of 3D files
To save time in working on the prototypes there are a number of simple things to consider when modelling and in converting the files that reduce to a minimum the "manual" work of correcting the files during the pre-production phase.
It is advisable to:
- Represent the model faithfully, avoiding discontinuous or overlaid surfaces (using the Snap command during the construction of the drawing)
- Create the model with a closed geometry (manifold). In other words it cannot be made of surfaces that have no thickness.
- Give a thickness of >=1mm to grooves so that they are evident and consistent.
- Avoid if possible thicknesses of less than 1,5mm, if this is not possible, to avoid them when making at the costing phase.
- Organise the model in layers in such a way as to allow for the elimination of unnecessary elements during production (working layers, axes, construction lines, reference profiles, etc)
Also:
- Supply a 2D measured drawing as a dimensional reference.
- File formats can be: *.igs, *.stl, *.dxf, *.dwg, *.3dm, *.stp,* .3ds, *.lwo, *.raw,* .mgx, *.skp
TECH Conceptual Modelers
These are physical representations of a model for evaluating style, ergonomics, costs and design.
The ideal machines for making these models are known as CONCEPT MODELERS.
The fundamental difference in these machines compared to other RP machines is that they can make prototypes in a very short time, so that the designer can verify immediately possible errors.
The special characteristics of these modellers are:
- High speed construction
- No problems related to environmental impact
- Low production cost
Typical Applications:
- Evaluating style
- Design verification
- Ergonomic verifications
- Cost evaluation
- Models for silicone moulds
- Models for investment casting
- Models for sand casting.
An example of a concept modeller is the 3D printing machine.
The machine was patented by the M.I.T in Boston and is currently considered to be the fastest machine in the world in the field of Rapid Prototyping with a speed of construction of 25 to 50 mm/hour.
The 3D printer is able to automatically construct three dimensional physical models directly from CAD files, allowing designers to have an object in their hands instead of interpreting a 2D drawing on paper or a screen, made in just a few hours.
This technology has shown itself to be able to respond to four important demands in the field of design:
Simplicity and faithfulness:
Direct dialogue with the most advanced design tools exploiting CAD models without changing the shape in any way;
Versatility:
Can be used in many fields such as: architecture, design, fashion, toys, domestic appliances, automobiles, shows, medical, etc.;
Speed:
Prototypes can be made from CAD models in a very short time (24/48 hours);
Economy:
The models created have a low cost compared to those made using other RP techniques.
HOW DOES A 3D PRINTER WORK?
Imagine that your Inkjet printer has instead of a sheet of paper a tank (construction table) 20cm deep and that the head sprays a binder in place of ink.
Now imagine that the CAD model is sliced into horizontal layers and that each resulting section is reproduced by the printer head on layers of plaster as if they were several overlaid sheets.
The machine takes a layer of plaster (plaster or starch based powder) from the supply table and spreads it over the construction table.
At this point the cartridge deposits a binder on the layer of powder, drawing the outline of the object and forming the first section of the model.
Another layer is spread out and a new section is printed. The process is repeated layer after layer until the physical model is completed.
The object is then carefully taken out and the excess powder removed.
Advantages:
- The powder with which the model is built becomes the support for the model itself which allows for the construction of models with undercuts without the problem of eliminating supports.
- The materials used are plaster or starch based powders, completely non toxic, biodegradable, solidified with a water based binder.
- The pieces can be infiltrated with wax, polyurethane, thermoplastic elastomer, epoxy resin, cyanoacrylate based coating or other materials to create specific mechanical properties in order to satisfy a wide range of modelling requirements such as smoothing, waxing, painting, metallization, thermoforming, silicone moulding, investment casting and sand casting.
Appearance of model:
Resined plaster, ivory natural colour with a smooth finish.
