Re: EMC & Linux

hi Jon & Tim,

suggest making the deceleration override a G-code instruction as you want
to turn it on for the many short moves of an interpolated spline as you point
out, but on a square feature on the same part you want the motion completing
in one axis before starting in the other.

an even better approach is found in a commercial control i use at work
which has a parameter set in G-code which they call "Tangency factor" that
automatically controls the overlapping accelerations between blocks based
on the angle. (how it works i don't know -- not open source -- mfg Thermwood)

-ron

On Sun, 6 Jun 1999, Jon Elson wrote:

> Tim Goldstein wrote:

---snip---

> > > kept running it lower and lower just to try it out. At
> > > Acceleration set to
> > > .05 it does this lazy motion thing. At .15 it looks ok. When I cut parts
> > > I will check it for sure.
>
> This is the blending of moves. It can be a problem when you make an X
> move, then a Y move, as the Y move will start to ramp up when the X move
> just begins to ramp down. But, for a string of short continuous moves describing
> a fluid curve, you need this, or the machine will absolutely CREEP. (My
> antique AB suffered from this.)
> Maybe we should ask Fred Proctor for some sort of switch (either in
> the RS-274 program (G-code) or on the user interface) to turn this
> on and off.