I have been experimenting with various materials to find an appropriate oscillating "mast" to support a striker in a wind driven musical sculpture. 6mm carbon fibre tube looked very promising except that it displayed a distinct bias in its patern of deflection. I assumed that this was a result of the process of it's manufacture and purchased some carbon fibre rod expecting this to behave in a uniform manner. Disappointingly the rods (especially in small section) display at least as much bias as if they are made up of ribon layers rather than strand. Any suggestions?

I guess it is possible that some stresses are set up in the rod from manufacture.

There could also be some very slight movement of the fibres while it was pultruded.

Other than that I would agree that the rod should be able to deflect in all directions more or less.  Maybe it is too stiff and as such flexes only in the direction of its natural weak point.  A thinner rod may flex more randomly.

Other than that I can only suggest perhaps another material.

Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant