Re: Re: Van Norman #12 Milling Machine

<< It seems to a beginner that backlash would not be a problem
because of the weight of the head and if better positional accuracy was
needed replacing the original acme threaded rod with a precision rod would
do the job. I would think that most of the cutting forces would be 90
degrees to the z axis and it doesn't seem like enough force would be
generated in that axis to overcome the weight. >>
Terry,
I have seen instances where Z thrust would overcome the weight of the head.
A large drill bit, a dull endmill plunging, head dragging or binding on
dovetail due to side cutting forces etc.

Peter

In CNC, the more you can cut out backlash,the happier you will be.