Re: Accuracy of i and j for arc centre

--- In CAD_CAM_EDM_DRO@yahoogroups.com, Ray Henry <rehenry@u...>
wrote:

>
> > From: "sid8ball" <sid8ball@h...>
> > Subject: Accuracy of i and j for arc centre
> >
> >
> > Can anybody tell me how accurate i and j have to be.
> > In metric i am rounding down to 3 decimal places and in imperial

im

> > rounding down to 4 decimal places.This could lead to a 0.001

error

> > in metric and a 0.0001 error in imerial. would this be a problem?
> >
> > I dont want to use r instead of i and j
>
> Hi Sid
>
> With the EMC, you can adjust this to suit yourself and recompile.

We look

> at arc endpoint to compute whether the arc center is correct. Six

places

> was the default in inch but I think that four or even three is

closer to

> the default now.
>
> Ray

ray,

From what you have said i can asume theres is no + or - tollerance
it is either right or wrong to 3 significante figures. I think the
best way is to round to 6 figures in the equation untill the final
answer and round that to 3 or 4 figures.

cheers

Sid