Re: what the world needs now ... backlash aware stepper motor drive r

--- In CAD_CAM_EDM_DRO@y..., "Daniel J. Statman" <dan.statman@r...>
wrote:

> Are you suggesting that the "add reverse steps to take up backlash"

should

> not be used in the interim, before more advanced control software

can be

> written? Do you think that it makes the machine work less well

compared

> with no backlash compensation at all?

A machine with sloppy acme screws cannot be fixed with software.

You will not be able to reliably climb mill and take full advantage
of the 2/3 reduction in spindle horsepower requirement for the same
material removal.

A machine with fairly good ballscrews can be made to shine with
backlash compensation. A slightly obround interpolated hole will
become near perfect. Typically within .0002 to true position in a
system with as much as .0008 backlash. 4:1 improvement or better,
within limited feed and acceleration ranges

Backlash compensation in the neighborhood of .001 or less is
practical. If you have any more, fix the machine as no amount of
fancy software algorithms will make up for the sloppy machine.

Best Regards,

Fred Smith
IMService