Compensating the plate radius

Tip and Trick – 2011-09-05

TB-DECO

A major function offered by the TB-DECO is the use of plate radius compensation in turning operations. The main advantage is being able to use standard tools commercially available on the market, especially from certain machining diameters upwards. However, some basic concepts are essential to understand the principle of use. This article serves to help you (re)discover this functionality.

1. The plate radius (R)
Let us consider the contour of part A-B for external turning:

Fig. 1 Without compensation

P1-P6:	points programmed in the ISO TBDECO code (figs.1 and 2)
red dash:	form error (fig. 1)
blue point:	theoretical tip of the tool (figs. 1 and 2)
red points:	tangent points at segments (fig. 2)
blue dashes:	path from the center of the plate radius (fig. 2)

Fig. 2 With compensation

In Fig. 1, the tool is positioned according to the points (P1 to P6) defined in the program, without any compensation. It can be seen that a form error (in red) appears at the P2-P3 path. In Fig. 2, the positioning of the tool no longer takes place at the theoretical tip but the system compensates the position by taking account of the plate radius. It places this last tangent at the path segments. In fact, the TB-DECO always takes account of the next segment in order to position the tool correctly at the time of active correction. Outside the compensated path, the software only considers the theoretical tool tip (point P1 and P6).

Compensating the plate radius