One of the specialities of design bureau
Sinot Design Associates in Laren (NH), the Netherlands,
is the design of new perfume bottles. The bottles are designed using Alias CAD software,
capable of calculating superb presentation renderings. However, in order to present a new
design to the customer for evaluation, a physical prototype is needed as well. SDA’s model shop
uses DeskProto and three desktop CNC milling machines to produce these models.
These perfect presentation models have been machined from two sides in transparent perspex (acrylic), after that polished to high-gloss, and after that furnished with lettering and cap. Presentation models of glass objects cannot be manufactured using any layer oriented RP technology.
You can also find the van Gils perfume bottle in the gallery of
Sinot Design Associates .
Other DeskProto users with famous brand names in this application field are:
Avon Cosmetics in New York,
Lancome in Paris.
Milling acrylic needs special conditions in order to achieve a good result.
Below you can find a few tips by Delft Spline Systems.
We have machined two models of the DeskProto example perfume bottle (see lesson 2 of the
Tutorial). The material used is a block of cast acrylic. The first model was machined in a standard way, the second model with special 'acryl-care'.
See the picture shown above for the difference: the first model was rather rough, with a milk-like surface. The second model was very smooth and already almost transparant: so easy to polish.
Differences in conditions were:

STL file of a higher resolution (more triangles).

special cutters for acrylic (different grinding angles) from
Hufschmied in Germany, versus standard cutters for steel with the first model.

climb milling (when meandering you can clearly see a quality difference between the climb and the conventional movements).

continuous coolant air (compressed air) during machining: for cooling and for removing the chips.
For cooling acrylic, plain water is even better, however our desktop machine cannot handle liquid coolants.
Cooling can also be improved via the cutting tool: HSS (High Speed Steel) cutters are better conductors for heat than carbide cutters, which will help to keep the temperature low.
Finally: the shorter the cutter and the shorter the cutting length of the cutter, the less vibrations during machining. This applies to any material. Of course in many cases a long cutter is needed in order to reach the complete model.
.