Re: Max feedrate

Hi,

What are the factors that determine the max. feedrate? The max.
steps/sec that can be output by the computer or the driver (max.
volt, amp. etc.)?


--- In CAD_CAM_EDM_DRO@yahoogroups.com, "knives01us <knives01@a...>"
<knives01@a...> wrote:

> --- In CAD_CAM_EDM_DRO@yahoogroups.com, "andrewyslee
> <andrewlee@s...>" <andrewlee@s...> wrote:
> > Hi,
> >
> > In Flashcut feedrate/ramping setup, one has to input values for

the

> > max. feedrate for the x-axis, y-axis and z-axis. Then there is
> > another "general setting" one for "max arc feedrate and one
> for "pt.
> > feedrate - linear". Am I correct to assume that this is the

overall

> > linear interpolation max feedrate? If so, I wonder if there is

some

> > connection between the max. feedrate for the x, y, z feedrate and
> the
> > max. linear interpolation feedrate
> >
> > Eg. if max feedrate for
> > x = 15 ipm
> > y = 15 ipm
> >
> > Should one set the max linear interpolation feedrate to be also

15

> ipm
> > or since linear velocity may be a vectorial addition of the x
> > velocity and the y velocity, it should be set higher, example,
> > 15 ipm X squareroot 2 or something like that?
> >
> > Thanks
>
> ::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

:

>
> I'm kind of new to Flashcut & CNC myself, but when I was setting up
> my machine I discovered that it will only tolerate about 1/3 the
> seperate axis feedrate when doing a 2 axis move. Test it yourself
> with a simple G code program like:
>
> G01 X5 Y3 F (fill in your test feed rate)
> G01 X0 Y0
>
> and check to see if steps are lost. I got the circular

interpolation

> figure much the same way, having the machine do a 2" circle drawn

in

> Cad and converted to G code until I found a speed that didn't drop
> steps, which was only about 1/6 of the fastest single axis move
> possible.
>
> Once you get the fastest feedrates for these 2 settings, you'll
> probably want to derate them to %70 of their values for reliability.
> Now that I have the machine setup right, it will run hours on end
> with no step loss.