To define the boundary of a scan in the scan dialog box (Insert | Scan), PC-DMIS allows you to key in or measure points, or use CAD data.
A sample Boundary Points area
This function is only available for DCC scans.
LINEAROPEN - These scans can also be measured without an end point. Delete the end point, and PC-DMIS keeps measuring the scan until you manually stop it. You cannot delete the starting point and direction point.
LINEARCLOSE - These scans need to have the start and direction points. You cannot delete or add boundary points.
PATCH - These scans need to have at least three boundary points to create a triangular patch to work with. You can use the Add and Delete buttons in the Boundary Points area to add or delete extra points. It adds a Closed Scan check box to this area.
Use the Closed Patch Scan check box to indicate that you would like to scan a closed feature like a cylinder, cone, slot, etc. If you select this check box, PC-DMIS reduces the number of boundary points needed to define the scan boundary. You would need to enter only the start and direction points and an end point. The end point indicates how far down and up the feature the scan needs to execute. The start and direction points together with the Initial Vector define the Cut Plane vector. Usually, the Cut Plane vector is parallel to the axis of the feature that you are measuring.
SECTION - Section scans use this area to set the boundary points for the SECTION scan, find holes defined in the CAD data, and toggle between displaying data for holes or for boundary points. Section scans add the Cut CAD and Show Cut buttons to this area for this purpose.
After you define a boundary and click Cut CAD, PC-DMIS automatically searches through the CAD data for any hole features along the scan's path. Any hole edges along the scans path are indicated with a integer for the point followed by a "H" (i.e. 2H, 3H, etc.). The hole edge points are set at a default distance of 0.0787 inches from the theoretical hole edge.
You can cut CAD with specific, user-selected surfaces. To do this, select the boundary points, select the Select check box, select the desired surfaces, and then click Cut CAD. PC-DMIS then cuts only the selected surfaces to find the hole or holes.
You do not need to click Cut CAD if your CAD does not contain hole features. If you do not use this button, PC-DMIS scans the part using the given start and end boundary points.
When cutting surfaces, PC-DMIS uses only the surfaces that appear in the first View (the Blue View).
See "Setting up the Screen View" in the "Editing the CAD Display" chapter. When you have a complex CAD drawing with multiple surfaces, you can arrange groups of surfaces into CAD levels. (See the "Working with CAD Levels" topic in the "Editing the CAD Display" chapter.) Doing this helps you restrict Section CAD Cut operations to specific portions of the CAD model.
Use the Show Cut button to switch between displaying boundary or hole data. After you define a boundary and select the Cut CAD button, click Show Cut to switch to the appropriate display.
PERIMETER - These scans works the same as the LINEAROPEN scan.
ROTARY - These scans require you to have at least a start point and a direction point (shown as 1 and D respectively in the Boundary Points list and on the CAD display).
If you don't have an end point (shown as 2), PC-DMIS continues to measure the scan along the specified direction until it returns to the start point.
If you have a start point and an end point, PC-DMIS scans along the specified direction until it reaches the end point.
PC-DMIS defaults to providing you with a start, direction, and end point in the Boundary Points area. You can delete the end point, but you cannot delete the start or direction point.
As you define each boundary point (by either clicking on the CAD or typing in the values), PC-DMIS automatically snaps each point to the radius distance from the center point unless you didn't define a radius. In this case, the first boundary point you define also defines the radius.
The Boundary Type area is only available in DCC mode for Linear Open, Linear Close, Patch, Section, and Rotary scans.
More:
Setting Boundary Points Using the Keyin Method
Setting Boundary Points Using the Measured Point Method
Setting Boundary Points Using the CAD Data Method