If an existing product has to be modelled on a computer, then digitising the product provides one solution to the challenge. Or it would do, if engineering departments could afford the price of many of the digitisers on the market. The good news is that they are getting cheaper.

One such product is Microscribe 3D from Patrick Thorn. According to the company, there are no complex environmental set-ups, the digitiser can just be plugged into an available serial port, and the engineer can start working. Also, they say, it is as easy as using a pencil.

Microscribe has a precisely counterbalanced precision mechanical arm with five degrees of rotational freedom, so it operates with a fluid motion and involves very little effort from the user. Precision optical control encoders are located in the joints and base and track the roll, pitch and yaw, as well as the x, y and z coordinates in relation to the stylus tip. The accuracy for the engineering version of the digitiser is 0.23mm and the sampling rate is 1000 points per second.

Software is available that allows 3D models to be constructed using points, lines, polygons, splines or NURBs. Data can be exported in most standard formats, including DXF and IGES.

As well as digitising geometry, Microscribe can report data so quickly it can be used in real time to manipulate objects, control views, control light sources and define animation trajectories.

The product works with Microsoft Windows, Silicon Graphics and Apple Macintosh platforms.

Figure 1: It is purrfectly easy to digitise using Microscribe 3D

{{Patrick ThornTel: Wraysbury (01784) 466474Enter 600}}