## Constructing a Cylinder Feature

Construct Cylinder dialog box

PC-DMIS allows several methods for constructing a cylinder. The following table lists the various types of constructed cylinders, along with their necessary inputs. Some features may require no inputs while others may require six inputs or more. In the following table, the term 'Any' indicates that the construction can take any type of feature as input for construction. PC-DMIS allows the features to be selected in any order.

CONSTRUCT FEATURE TYPE | SYMBOL IN EDIT WINDOW | # OF INPUT FEATS | FEAT #1: | FEAT #2: | COMMENTS
Best Fit Cylinder | BF | At least 6 inputs are needed. See Note below. | - | - | Constructs best fit cylinder using given inputs
Best Fit Recomp Cylinder | BFRE | At least 6 inputs are needed. (1 must be a point) See Note below. | - | - | Constructs best fit cylinder using given inputs
Cast Cylinder | CAST | 1 | Any | - | Constructs cylinder at centroid of input feature
Project Cylinder | PROJ | 1 or 2 | Any | Plane | 1 input feature will project cylinder to work plane
Reverse Cylinder | REV | 1 | Cylinder, Cone, Line, Slot | - | Constructs a cylinder with a reversed vector

Note: Best Fit and Best Fit Recomp Cylinders can now be constructed from two circles. The input circles must be of type Constructed Best Fit (BF) / Best Fit Recompensate (BFRE) or Measured circles. The total amount of hits in each circle must be at least three.

Note: If you select inappropriate feature types, PC-DMIS displays "Cannot construct [feature]. Combination of input features not accepted." on the status bar.

To construct a cylinder:

1. Access the Construct Cylinder dialog box (Insert | Feature | Constructed | Cylinder).

2. Input the desired features.

3. Select the method of construction. Available options include:

- Best Fit or Best Fit Recompensate Cylinder

- Cast Cylinder

- Projected Cylinder

- Reversed direction Cylinder

- Auto Cylinder

4. Click the Create button.

The Edit window command line for a sample Cylinder Construction would read:
feature_name=FEAT/CYLINDER,TOG1,TOG4,TOG5
THEO/x_cord,y_cord,z_cord,i_vec,j_vec,k_vec,diam,length
ACTL/x_cord,y_cord,z_cord,i_vec,j_vec,k_vec,diam,length
CONSTR/TOG2,TOG3,......

Note: The actual Edit report will be displayed in all CAPS.

AUTO is the default method of construction. This option automatically determines the best way to construct a cylinder using the input feature(s). See "Auto Cylinder Construction" | The following text is the basic format for cylinders. TOG1= POLR or RECT TOG2 = CYLINDER TOG3 = BF / BFRE / CAST / PROJ / REV TOG4 = IN / OUT

TOG5 = LEAST_SQR / MAX_INSC / MIN_CIRCSC / MIN_SEP / FIXED_RAD (only for measured, BF and BFRE circles)

length = is measured between the first measured circle (first three hits) and the furthest point away from the first three hits.

The first three lines displayed in the Edit window will be the same for constructed cylinders. The fourth line will be slightly different, according to the type of feature being constructed. You can switch between the different types of cylinders by placing the cursor on TOG3 and pressing F7 or F8. (See "Command Mode Keyboard Functions" in the "Using the Edit Window" chapter.)

When two or more features are involved, PC-DMIS automatically determines the necessary order of the input features. This improves the accuracy of the measurement process.

The following paragraphs describe the available options for constructing a cylinder:

More:

In / Out Cylinder

Constructing a Best Fit or Best Fit Recompensate Cylinder

Constructing a Cast Cylinder

Constructing a Projected Cylinder

Changing the Direction of a Cylinder

Auto Cylinder Construction