  We show that Weyl points with topological charges 1 and 2 can be found in
very simple chiral woodpile photonic crystals, which can be fabricated using
current techniques down to the nano-scale. The sign of the topological charges
can be tuned by changing the material parameters of the crystal, keeping the
structure and the symmetry unchanged. The underlying physics can be understood
using a tight binding model, which shows that the sign of the charge depends on
the hopping range. Gapless surface states and their back-scattering immune
properties are also demonstrated in these systems.
