This feels a lot like:
However, you would need the relief grind to vary with Z axis movement, according to the flute spiral angle.
I actually did that relief turning using the "hexbore" component that is also used for the hexagonal boring demo.
This is the HAL component (And the part of the HAL file which connects it).
For grinding spirals I would suggest adding two more pins, one to receive the absolute Z position and another that gets the tangent of the flute angle (no point working out the tangent in the realtime thread, it doesn't move)
You can remove the sections that are active if relief == 0, those are for polygon mode.
Code:
component hexbore "A component to bore polygonal holes";
include "rtapi_math.h";
pin in float spindle-position "scaled 1.0 per rev";
pin in float radius "halui.axis.x.position-relative";
pin in unsigned facets=6;
pin in float relief = 0;
pin in bit enable;
pin out signed offset "scaled x10000";
pin out float angle;
pin out unsigned version = 6;
function _;
license "GPL";
author "andy pugh";
;;
double fmod(double x, double y){
return x - y * (floor(x / y));
}
FUNCTION (_){
if (! enable || (facets < 4 && relief == 0) || (facets <1 && relief != 0)) {
offset = 0;
return;
}
if (relief == 0){
angle = (fmod(spindle_position, 1.0 / facets) - 1.0 / (2.0 * facets)) * 6.283185307179586;
offset = 10000 * ((radius / cos(angle)) - radius);
} else {
offset = 5000 * relief * (cos(spindle_position * facets * 6.283185307179586) - 1);
}
}
And the HAL file:
Code:
loadrt hexbore
addf hexbore.0 servo-thread
#halui...pos-relative includes the eoffset
loadrt sum2 names=sum2.rad
addf sum2.rad servo-thread
setp sum2.rad.gain0 -1
net rad-offset axis.x.eoffset-request => sum2.rad.in0
net rad-raw halui.axis.x.pos-relative => sum2.rad.in1
net radius sum2.rad.out => hexbore.0.radius
setp axis.x.eoffset-scale .0001
net spindle-revs hexbore.0.spindle-position
net offset axis.x.eoffset-counts hexbore.0.offset
