How to add formulae to machining
Formula can be entered for machining instructions. These typically might locate the start or end of a drill or rout operation, or the number of drill holes may depend on the part length (X) or part width (Y). For example a vertical drill instruction:-
Function Vertical drill
Description Std shelf holes
Xstart Y+25
Ystart X+120
Diameter 12.0
Depth T(@SHELFMATERIAL@)/2
Repeat INT(X/200)
Direction U
Offset
Tool 32
In this case the set of holes for a shelf start at a fixed inset position on the end panel of the shelf (Y+25 and X=120) and the number of holes depends on the overall height of the book case (the length of the end panel) as a whole number divided by the fixed distance between the holes (INT(X/200).
This allows the same end panel to be used for a variety of heights of bookcase and the drilling operations are automatically adjusted for each variation.
Variables - these can also be used in Machining, for example: T(@SHELFMATERIAL@).
The function T(material) gives the thickness of the named material. Instead of a fixed material name a variable can be used - this is useful where, for example, shelf material may vary with the product.
Formula table
Formula can also be pre-defined in a table. This allows a formula to be linked to a simple name. For example:-
XBORE: X start for shelf holes: (X-18)+3
YBORE: Y start for shelf holes: (Y-24)+6
The formula name can then be used instead of the actual formula in instructions:-
xStart &XBORE&
yStart &YBORE&
This helps to make the instructions clearer, easier to enter, and less prone to error. It also allows use of a single formula where the same formula occurs in several different situations.
The demonstration data has several examples of Parts with Machining instructions (drawings) defined with variables and formula.
