Contour Velocity At Corners - HEIDENHAIN TNC 426 PB/M Technical Manual

Table of Contents

6.10.2 Contour Velocity at Corners

As of NC software

December 2001

To comply with a defined tolerance, the TNC can reduce the tool velocity

before reaching machining corners, line-to-arc transitions and arc-to-arc

transitions. The control can react to a potential violation velocity tolerance up

to 128 blocks in advance. This feature is known as "look ahead":

Define the permissible tolerance for contour transitions in MP1096. The

larger the tolerance, the greater the tool velocity.

The user can overwrite this tolerance with Cycle 32, "Tolerance."

Jerk limitation (See "The Interpolator" on page 6 – 113) and nominal-position-

value filter enable the TNC to machine 3-D surfaces at high speed.

Prerequisite: The contour must be described with short line segments.

To ensure that cutter-compensated outside corners remain exact, a spline

must be inserted into the cutter midpoint path instead of a transitional arc. A

spline also has the advantage of reducing the jerk:

Enter MP7680 bit 10 = 1.

Tolerance for contour transitions

0: No nominal position value filter

0.001 to 3.000 [mm]: Permissible tolerance at contour

Machine parameter with multiple function

%xxxxxxxxxxxxx

Bit 10 – Cutter-radius-compensated outside corners:

0: Insertion of a circular arc

1: Insertion of a spline curve

Proposed input value: %xx1xxxxxxxxxx

Bit 11 – Reserved

Contouring Behavior