I am hoping to use carbon fibre composite tube for the pendulum of a precision regulator clock.  I believe that the coefficient of thermal expansion of pulltruded carbon fibre composite is somewhere between 0.1 and 0.3 ppm /°C but wonder if you can give a more exact figure  for your tubes so that I can design a compensator.

Thanks in advance.

Edit:  The coefficient is I believe negative.

Hi All,

The problem with getting thermal coefficient data is often the manufacturers simply don't measure it.  It is not a commonly asked for bit of data with these kind of materials.

This is why generally you can only find generic figures for carbon composites.

This is even more the case with resin and raw fabrics as even if they could measure figures for each material, often they are meaningless when the material is only ever used in the form of a composite where the performance would be significantly different.

For our specific tubes, we have been asked about the thermal coefficients before and having checked with the manufacturer they don't have any test data.

Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant

O.K. Thanks Warren.  I guess I'll just have to try it out and if it isn't good enough then make a compensator.

Russell.