Timber NC - BVX

In Timber, initially all parts have a rectangular cross section and all parts are prismatic.
In total, initially, each part has 6 faces: four longitudinal and two end faces.

On the Hundegger machine, the longitudinal faces are numbered: 1,2,3,4 and the end faces are denoted as Front and Rear.
Next image illustrates this.

Image

In the appendices these numbers are used to define configurations.

Some operations are Separating operations (S)
Some operations are Discrete (D)
Some operation can be either Separating or Discrete (S ; D)
Some operations are Profiling (P)
Some operations can be either Discrete or Profiling (D ; P)
Some operations that are Annotative (A)

Next table shows the list of current available operations (processes) and their type. 
 

Construsoft developed some tools. The table shows for which operations this is the case and which tool can be used to model them.

In BVX, a cut is a planar operation that separates a portion of a solid.

Modelling:
A Cut operation can be modelled using a either a Fit or a Trim command.
When there is only one saw cut at an end then it should be modelled using a Fit.
When there is more than one saw cut at one end then the first Cut should be a Fit and all subsequent others should be Trim.

Remark(s)
There is no parameter to control the distance over which the Cut operation stretches. Therefore, a cut will always start and end in thin air.

In BVX, an operation is defined on a reference side (RS) and described by its:

• Position
• Orientation
• Geometry

 
Review the BVX File format description and the native BVX file viewer for details.

Each operation has its own scope with respect to:
- The faces on which it can be defined
- How many faces it can affect 
- The shape of the removed solid
- Orientational parameters

Because of scope and definition, there are cut outs that can be modelled with more than one BVX-operation. There are however also cut outs that only suit one specific BVX-operation.

Next image illustrates this:

Image

In general:
The dimensions of a rectangular block shape are unambiguously described by three independent parameters.
In space, the position of a volume is unambiguously described by three independent coordinates.
In space, the orientation of a volume is unambiguously described by three independent angles.

When one independent parameter is not present on an operation it means that the scope of that operation is limited because the “missing” parameter is calculated and, hence, is dependent.

Example1: Comparison between Housing and Lap in terms of dimensions:
A Housing has an independent parameter that controls the width 
A Lap does not have an independent parameter that controls the width.

  

Image

This is the reason why operation C can be described as both a Housing and a Lap and operation B cannot be described by a Lap.

Example2: Comparison between Housing and Slot in terms of orientation.
A Housing operation has an independent parameter to control the in-plane angle.
A Slot operation does not have an independent parameter to control the in-plane angle.

  

Image

This is the reason why operation D can be described by both a Housing and a Slot and operation E cannot be described by a Slot.

  

Image

Next image shows the coordinate system on the machine.

Image

In BVX, an operation is described on one of the four longitudinal faces of the virginal solid. In BVX this face is denoted as reference side.
  

Image

Image

An operation is defined on a Reference side.
Each reference side has its own local coordinate system in which the position of the operation is described.

Image

As mentioned, the position and orientation of a 3D-solid can be unambiguously described by 6 independent parameters, three for position and three for orientation.

The position is described by the values of LengthMeas, Q1 and Q2.

The angular parameters are the rotations about the axes of the local coordinate system of the applied reference side (LengthMeas-, Q1- and Q2-axis)

For operations that support more than one angular parameter, the order in which the angle values are applied must be maintained.

Review the BVX File format description and the native BVX file viewer for details per operation.

Each volumetric operation is to be modelled using a negative volume.
Note that the shape of the negative volume does not necessarily match the shape of the cutout:

Image

A rectangular, block shaped prismatic negative volume can affect either 1, 2, 3 or 4 faces of the virginal solid.
The actual shape of the portion of solid that is removed can vary as well. Most often this is either a

b. Triangular prism. Here it does matter whether the negative volume’s local x-axis is // to the parts local x-, y-, or z-axis.

Image

In this document, no combination of operations is mentioned. The reason is that there are too many combinations possible. Looking at single operations and considering:

• Number of faces affected  (1; 2; 3 or 4 faces) → 6 + 15 + 20 +15 = 56 permutations
• Shape of cutout (rectangular or triangular prism) → 2 permutations
• Direction of system axis of the negative volume that yield a triangular prism relative to the parts

So, in total:  56 + 3*56 = 224 configurations are considered. Each configuration is assigned a unique number.

Appendix A describes all possible configurations in which:
- The shape of the cutout on the solid is a single blockshaped rectangle.
- 1, 2, 3 or 4 faces are affected
- The orientation of the block is such that each side of it is // to one of the local axes of the part.

Appendix B describes all possible configurations in which:
- The shape of the cutout on the solid is a single right angled, trangular prism.
- 1, 2, 3, or 4 faces are affected
- The orientation of the triangular prism is such that its system line is // to either the local x-, y- or z-axis
of the part.

Note that some configurations cannot be modelled or make no sense. In the Appendices, these configurations are denoted in red.

Some operations and combinations of operations are hard to model manually. For these, Construsoft developed dedicated tools.  These tools will assign the appropriate names to the negative volumes.

Tenon- and mortise                        → J150
Dovetail tenon- and mortise         → J151
Lap Joints                                          → J152
Ridge/Valley cut                               → d153

Image

Image

Image

Image

What follows can best be viewed in concurrence with the model: BVX-operations.
The model contains all configurations mentioned in both Appendix A and B.
The configuration number is represented by the Finish attribute on the part.

Image

For each operation mentioned below, there is a filter.
The name of the filter is BVX_[Operation], e.g.: BVX_RABBET.
The filter only shows the configurations that can be exported to the operation mentioned in the filter name.

Scope per operation
The name of an operation is denoted in three environments:

• The GUI of the export tool
• The actual BVX file
• The SC-Viewer

 
Unfortunately, the name of certain operations is not the same in these environments.
In next overview the table header is the denotation in the BVX file, the other two denotations are shown in the table. 

Note: The tables indicate the theoretical scope of each operation. It does not take into account whether or not it is practical to apply a certain operation in that configuration.