Re: Re: Low cost Servo Controller

> From: Ray Henry <rehenry@...>
>
> Bertho
>
> I spent years keeping up a bunch of Hardinge lathes that were controlled by
> AB 73xx controllers. They used 15 bits from the digital to drive their D/A
> board. That's 1600+ steps plus direction if mscalc works the way I think it
> should. They would do an excellent job on shallow tapers where one axis
> runs very slow compared to the other and on cutting a radius or half circle.
>
> To me that's the critical question. What are the very shallow tapers going
> to look like? What are the four corners (where axis motion slows to a stop
> and then reverses) of a milled circle going to look like? 128 steps are
> more than adequate for the high end of axis motion. Will they be enough
> for the low end of feedrates.
>
> The stg card uses 13 bit for both D/A and A/D. (8000+ levels)
>
> Ray