Thankfully I never had to try and drill holes in sub mm size being around spindles spinning 2 to 5 x faster than a dentist drill on machines that weigh a few tons is not my idea of pleasant working conditions I'll take an old 13" to 20" column radial arm with a spindle range from 15 RPM to 1800 RPM any day over one of those things or my square post Cleereman or my 6 drill