Re: [CAD_CAM_EDM_DRO] Re: How to establish repeatable home position w/steppers?

Rick Dulas wrote:

> Howdy! It occurs to me that using an encoder on the motorshaft as the
> reference for the home position doesn't tie home to any particular point
> in space. Wouldn't it be better to have "home" be an independently
> located point? Imagine that we move out 30 steps in the X dir and then
> return those 30 steps back to our departure point. We then declare that
> we are back where we started from because we counted our steps. This
> lacks what cartographers call "ground truth".
>
> I would prefer to establish "home" independently of the means of
> movement, and check that my 30 steps really brought me back "home". But
> maybe I don't have enough faith. <G>
>
> Rick Dulas

My Allen Bradley control uses microswitches. When homing, the control moves
the axis until the switch is closed. It then reverses at a slow rate, moves the axis
until the switch opens and then looks for the encoder index pulse. Very repeatable..
Larry...