Re: [CAD_CAM_EDM_DRO] Re: 4th Axis Concept (long)

Chris Luebke wrote:

> Interesting on the "Master Zero Position" concept. I didn't think of that, if
> it is out there. Could be made I suppose even using a real basic technique
> like one very accurate switch somewhere in the rotation. But, then you would
> have to orientate the part correct to that switch to start with. The next
> issue with that is making sure that we can get the under $1k PC based
> controls to handle the "searching/indexing" necessary to know where 0 is on
> that part.
>
> Servo Experts ? Anyone?

if it is a servo system (or any system with an encoder) it should be able to
handle the index position. That is really just 'home'. Anything based on the
7166 and 7266 encoder counter (Servo-to-Go and the Dan mauch DRO)
has this in the chip, at least. The Servo-to-Go has index on all 8 axes.
My parallel port axis control cards also support the index signal.

EMC has a home function that runs the selected axis slowly until it hits the
home switch, then uses the index pulse to refine the home position to the
single encoder count.

This feature has been used on mills. There are some ramifications on a
spindle, where the index just keeps coming around and around.

Jon