Re: G92

[Brian Pitt <bfp-at-earthlink.net>]

thanks Dale

I was wondering why I'd never used g92 and what all the hubub was about

so from what I've seen on the CCED list some are using it to make up
for a lack of offset setting and manipulation controls in the user interface
and there realy isn't a bug in the interpreter at all right?

Brian

On Thursday 18 July 2002 08:15, you wrote:
> G92 - position register preset/position preload/load position or
> whatever the Mfg. called it.
>
> G92 is NOT an OFFSET!!! It simply changes the value of the position
> register. It was meant to be used within a part program, not from MDI
> mode to set axis zero or program origin point.
>
> In my nearly 30 years of experience every machine I have ever dealt with
> had a method of setting axis zero manually and it had absolutely nothing
> to do with the G92 code. The earlier machines had no offsets at all, but
> G92 was included in the G & M codes. Next came tool length and diameter
> offsets, program origin was still established by manual setting of axis
> zero. Then came Work Coordinate Offsets. The first machine I encountered
> that used G54,55,... still had the button for setting an axis to zero in
> manual mode. G92 was still separate from the offsets. As for the setting
> of an axis zero point, with the addition of Work Coordinate Offsets I
> found no reason to ever set axis zero the old way and used the Work
> Coordinate Offsets.
>
> A Simple Example:
<snip>

> There can be many Right ways to do something, but Wrong is Wrong no
> matter how you look at it! IMO to use the G92 code as an offset is wrong
> and can lead to problems as have been described.
>
> Dale