Standard Notches

A standard notch is selected by a notch designation (string) of the following layout.

<notch designation> ::= <type> <par_1>*<par_2>*….<par_n>

<type> is a registered 'name' of the notch.

<par_i> are parameters controlling the dimensions of the notch.

In certain notches some parameters are optional and have default values. Suppose a notch with four parameters of which the last two are optional:

NOT<a>*<b>*<c>*<d>. If in such a case the user wants to give the last parameter <d> but stay with the default value for parameter <c>, this parameter must be replaced by a zero, that means, NOT*<a>*<b>*0*<d>.

Examples:

• R50 specifies a circular arc with radius 50 mm

• HE250*125*100 specifies an elliptical notch ("edge hole") with major axis 250 mm and a minor axis 125 mm and with a 100 mm wide opening against the edge. The toe height at the ends of the opening is by default 15 mm high.

The three menus below show:

1. Notches that may be used both in corners and along edges

2. Notches that are exclusively used in corners

3. Notches that are mainly used along edges. Under certain circumstances these notches may be used in corners as well.

   

   Figure 3:1. Edge and corner notches, menu.

   

   Figure 3:2. Corner notches, menu.

   

   Figure 3:3. Edge notches, menu

The survey below gives all required details about each notch: how it should be selected, controlled and used.

A standard notch is described in a co-ordinate system of its own. It is normally positioned and orientated by reference to items in the model, for example, corner or limits of the panel. A user need normally not bother about how a standard notch is described in its own co-ordinate system.

Certain types of standard notches (currently the types HKE, HKO, VUR, VDA, VDB, VOA, VOB, KD, KE, KO, and KR) have toes with sharp corners.

An option has been implemented to soften these sharp corners by a fillet arc. The radius of this arc is set by the environment variable SBH_NOTCH_TOER. Simultaneously, the built-in toe height may be changed by another environment variable SBH_NOTCH_TOEH.