Particles/Hair: How do I adjust the normal so the spikes go the same way around the object? Is there a way to adjust the up/rotation of a face's normal, so all the spikes flow the same way on the object

For some reason they seam to flip over when I apply this particle system to the simple cylinder and cube.



Hmmm, i've noticed that when using emitter as oppose to hair, then the normals dont flip round...




Except, curve to mesh, type objects, the normals twist around....
After a lot of web digging and experimenting, the answer was in the manual!

In the Particles panel enable the Rotation option, and set Initial Orientation to Normal-Tangent. BUT you need to have created a UV map for this to work.

Depending on the shape of your faces, the UV Reset option in UV Mapping drop down can be useful setting the initial rotation too.