Five-axis machining - Akima spline

In addition to motion in the x-y plane, in the following program the tool of a fivefold head is guided perpendicular to a circle secant contour.

%L uprg_secant 
N01 #SET ASPLINE MODE[2, 2] 
N01 P5 = 80 ( Radius ) 
N02 P3 = 64 ( Number of interpolation points ) 
N03 P4 = 360/P3 ( Angle staggering ) 
N04 G01 X-P5 F20 
N05 X0 
N06 G151 (Spline selection ) 
N07 $FOR P1=1, P3, 1 
N08 P2=P1*P4 F20 
N09 X=P5*SIN[P2] Y=P5*[1.0-COS[P2]] C[-90+P2] 
N10 $ENDFOR 
N11 G150 (Spline cancellation ) 
N12 XP5 
M29 
%Main 
N100 #KIN ID[9] 
N100 #TRAFO ON 
N150 A90 C-90 
N100 LL uprg_secant 
N300 #TRAFO OFF 
M30

Five-axis machining - Akima spline 1: — Figure 1-33 Contouring speed in the case of linear blocks with perpendicular oriented tool

The feed rate fluctuates very considerably due to the discontinuity in the rotary axis.

Five-axis machining - Akima spline 2: — Figure 1-34: Contouring speed in the case of a spline curve with a perpendicular oriented tool

When the spline function is active, the contouring speed is constant. The programmed contouring speed cannot be reached due to the limited rotation speed of the orientation axis. As, in addition to this, the motion component of the rotation axis does not change due to the constant contour curvature, the speed level on the contour can be kept constant.