The poor thermal conductivity of plastics requires that care is taken to prevent the area being machined from getting too hot. The type of tool, depth of cut, rate of feed and coolant flow may have to be adjusted. If a coolant is used, make sure it does not chemically attack the plastic.

Check the supplier literature for recommendations on the types of tools and speeds to be used with a specific material.

Tolerances
Many designers will arbitrarily put a +/-.005 in tolerance on a part if it is to be machined. Quiz the designer to determine if the tolerances can be increased. Look at a ruler to visualize the size of the tolerance and think about the tools available to make the cut. Work with the designer to specify the tolerances really needed to make his part work and discuss what can actually be produced with the equipment available.

For more information, contact Mike at Acrylics, Inc.