  Numerical simulations of convection driven rotating spherical shell dynamos
have often been performed with rigid boundary conditions, as is appropriate for
the metallic cores of terrestrial planets. Free-slip boundaries are more
appropriate for dynamos in other astrophysical objects, such as gas-giants or
stars. Using a set of 57 direct numerical simulations, we investigate the
effect of free-slip boundary conditions on the scaling properties of heat flow,
flow velocity and magnetic field strength and compare it with earlier results
for rigid boundaries. We find that the nature of the mechanical boundary
condition has only a minor influence on the scaling laws. We also find that
although dipolar and multipolar dynamos exhibit approximately the same scaling
exponents, there is an offset in the scaling pre-factors for velocity and
magnetic field strength. We argue that the offset can be attributed to the
differences in the zonal flow contribution between dipolar and multipolar
dynamos.
