Re: Question about angular and linear feedrates

Hi Brian,

OK, I think we're talking about the same thing! You'd also want to
increase the feedrate for dia's smaller then the "parity" diameter (my
1.1459").

Actually, at least in the way I calculate things (and I've been told I
do things backwards), I'd use the radius parm to effectively
increase/decrease the number of steps the Angular axis required, when it
came to finding "which axis has the biggest move". In my code, the axis
with the "biggest move" gets to move at the requested feed rate, and all
others are proportionately smaller. Further testing will tell!

Humm, It wouldn't be hard to add an 'R' parm to G02/G03, 'hope the
G-code cops don't ketch me!

Alan KM6VV


Brian Pitt wrote:

>
> hi Alan
>
> I see what your saying , but I'm thinking that having the baseline at
> zero would give the raw max axis rate to start with then any non-zero value
> in the radius parm would be used as a correction factor to scale the rate
> down from the raw value to make up for the larger circumfrence at the
> point of cut ,sorta like using constant surface feet on the lathe
>
> Brian
>
> On Monday 05 August 2002 16:18, you wrote:
> > Hi Brian,
> >
> > Yes, I can understand that! I'm thinking if the cut radius on the
> > rotary table is other then about 1" dia, THEN I must adjust my
> > called-out feedrate.
> >
> > Or for those writing controllers, considering the addition of a radius
> > parm? Maybe use of the alternate radius form of G02/G03 would be useful
> > here? Maybe THAT's why they did it?
> >
> > I'm comfortable knowing that I'll get about the same feedrate on my
> > hardware at 1" dia; and other then that, I'll adjust the feedrate as
> > required (this assumes that the 'A' axis (on my hardware/software) is
> > the fastest moving... I.E., needs the most steps to complete it's move.
> > Otherwise, the 'A' axis feedrate will be SLOWER then the other axis.
> >
> > This may or may not "industry standard". But it gives me a starting
> > point.
> >
> > Alan KM6VV