Re: [CAD_CAM_EDM_DRO] Re: mill threading, Acceleration, Axis

Alan Marconett KM6VV wrote:

> Dave, Ballendo, Jon and the list,
>
> Sigmoid? is that what you call the curve? I think mine looks like
> that. I have a table of delays that correspond to a table of step
> rates. I just walk the rate table and calc how many steps to let go by
> before bumping up to the next rate in the table.
>
> I pre-calc the deceleration point (I know the number of acceleration
> steps to go from starting rate to ending rate for a trapezoid ramp),
> continually "watch" for the next point to bump up, after the final rate
> is reached, no bumping until the deceleration point, where I start
> looking for decel points. Triangular acceleration, just start decel at
> the midpoint.

OK, OK, you guys are dangerous. I knew the name but not how to calc. it; but a little searching on the web and:

Sigmoid curve:

f(x) = 1/( 1 - e^-ax)

which should translate as

y = 1/ exp( -ax);

LOL

Dave