Re: [CAD_CAM_EDM_DRO] Tangential movement function design

Hi K,

Wouldn't you just calculate the angle of the line you're about to cut
(to the X axis)? And mind the quadrant. I see no dependency on the
direction of the previous line, unless you need to rotate in the minimum
direction. For that you have the previous angle. I'd rotate to
absolute angles, not incremental. Otherwise, you'd possibly have
accumulated errors.

Alan KM6VV


kdoney_63021 wrote:

> I need to be able to move my Z axis in a rotary direction to maintain
> a tangential perspective to my X and Y motion. Like putting a pizza
> cutter on my Z axis with a moving table design. I need to move the
> cutter in the proper direction (tangent) to the expected motion.
>
> I tried to avoid this complication by using a free floating drag
> knife design but I need to be able to reverse direction immediately
> and the radius on the drag knife is too large.
>
> I can easily attach a rotary axis to my Z and have the movement
> available but I need a general mathematical function for calculating
> the required angle. I was thinking a simple differential equation
> could output the required tangent but I simply have not been able to
> program the function in C to take into account reversal of direction
> or undefined tangents. The ones I have problems with would be like:
>
> last position x=0 y=0
> current position x = 2 y = 1 current Z angle is 33 degrees
> move to x=2 y = 6
> or
> last position x=0 y=0
> current position x = 2 y = 1 current Z angle is 33 degrees
> move to x = -2 y = -6.
>
> Does anyone have the function(s)? They don't have to be in C.
>