Modelling
Modelling from A to Z
Plastic Diamond Models
The diamond sector is applying three-dimensional models already for a long time.
Castings of rough diamonds are used as a tool for process decision-making.
The three-dimensional models of rough and cut stones are also very efficient
for educational purposes. During the various diamond courses on diamond evaluation and processing, models are indispensable. A picture tells much more than a thousand words. A 3D-model gives even more information.
Three-dimensional models can also be used for PR-purposes and in some cases help to avoid high insurance premiums.
This article lists some important processes used to make 3D-models. WTOCD applied CAD/CAM techniques to
implement a fast and universal method giving a high standard of results.
Different methods can be applied to produce models
Casts
Casting techniques can produce models very fast, but require a mould. The advantage of this technique
is that the mould is re-usable. The disadvantage is the need to remove burrs and traces of casting holes.
Rapid prototyping
Stereo lithography is a very often-used rapid prototyping technique. A 3D-model is build out of several
layers e.g. by hardening a liquid polymer under influence of laser light. The feasible resolutions
(layer thickness 0,125 mm and smallest detail 0,5 mm) are not sufficient to make diamond models.
Classic milling method
To mill a 3D-model with the classic method each facet has to be positioned under the mill, one
after the other. This manual handling is very time consuming and a lot of expertise is required.
Moreover calculations of angles and depths are necessary, resulting in a long production time.
CAD/CAM
The design (Computer Aided Design) and the preparation of the manufacturing (Computer Aided Manufacturing)
are computerized. The work preparation describes the way of milling and the necessary tools and cutting speed.
Finally a computer program for the milling machine (Computer Numerical Control) is generated.
WTOCD uses the CAD/CAM-method because of its important advantagesReproducibility
all design- and preparation has to be done only once
Independent of the complexity of the stone
rough stones and complex cut shapes can be milled without any problem.
Availability of 3D-drawings
contrary to 2D-drawings the 3D-drawings are always dimensional realisable. These drawings can for instance be used for registration of drawings and models.
Contact
Technical advisor Ing. Guy van Goethem, WTOCD
