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4 miscellaneous functions for contouring behavior, Smoothing corners: m90 – HEIDENHAIN TNC 410 ISO Programming User Manual

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HEIDENHAIN TNC 410, TNC 426, TNC 430

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7.4 Miscellaneous Functions for

Contouring Behavior

Smoothing corners: M90

Standard behavior

The TNC stops the tool briefly in positioning blocks without tool radius
compensation. This is called an accurate stop.

In program blocks with radius compensation (G41/G42), the TNC
automatically inserts a transition arc at outside corners.

Behavior with M90

The tool moves at corners with constant speed: This provides a
smoother, more continuous surface. Machining time is also reduced.
See figure at center right.

Application example: Surface consisting of a series of straight line
segments.

Effect

M90 is effective only in the blocks in which it is programmed with
M90.

M90 becomes effective at the start of block. Operation with servo lag
must be active.

X

Y

Independently of M90, you can use machine parameter
MP7460 to set a limit value up to which the tool moves at
constant path speed (effective with servo lag and
feedforward control). Not with TNC 426 or TNC 430.

X

Y