Description: Create a 90 tee between two cylinders of equal diameter. Edit the diameter of the tee-off to a smaller diameter.
Archive: http://www.revcad.com/Sheet5/Archive/Examples/cylindrical_tee.zip Tutorial Index
Details: Main Cylinder Diameter:150; Length:300; Orientation:X-axis. Tee-Off Cylinder Diameter:150 Length:150 Orientation:Y-Axis. Connection at mid point of main cylinder, 150 from each end.
Author: Trevor Maddison
Date: 11 January 2003
Concepts & Techniques:
1. Form a tee connection between objects.
2. Match the Tee-Off to the main cylinder.
3. Interrogating the match dependency and understanding how matching effect the design.
Design Image:
Procedure:
1. Create a single cylinder with orientation along the X-axis (See: Tutorial: Create a Single Cylinder ).
2. Select 'Create Part'
to begin creating the Tee-off object.3. Select the 'Snap Center Line '
tool. The center line of the first object will highlight in green to
indicate selectability. Select it with the mouse. The cursor will snap to the center line of the first part and
restrict 3D movement to slide along it.4. Type 150 in the edit box 'End1'. This selects a point on the first object center line at 150 from end-1 of the first object. The command now prompts for the second point and the cursor should be 'rubber banding ' the new object from the first point to the current 3D cursor position.
5. Use the Axis Snap tool to align the active second object to the Y-axis. Type the length into the 'Length' edit box in the command dialog. Move the cursor so the that the object aligns itself with the Y-axis. Select the point with the mouse. This fixes the object second point position and opens the 'Edit Part' dialog on the new object.
6. Do not alter any dimensions in the edit part dialog. Simply check that the 'Match Part' radio button is selected at the bottom of the dialog. This means that when the edit part dialog is closed a matching operation is initiated to match the edited part to one or more of its connected part. We are going to use the matching facility to ensure the second object cylinder size matches the first object.
7. Close the Edit Part dialog box. The matching process is initiated. The status line at the bottom of the main window shows the prompt 'Match Object'. The command dialog has edit/combo boxes for 'To', 'And', 'Displace' and 'Section' . In this case 'To' has only a single selection available because there is only one linked object to the new object.
8. Select 'Object-1' in the 'To' combo box to indicate that the current part (highlighted in cyan) should be matched to it (when the match button is pressed). The 'And' box has no selections because there are no available 'bridge match' objects.
9. In the 'Displace' box of the matching command dialog select 'Turn'. This means the part being matched (the new part - hghlighted in cyan) should be turned to achieve a match at both edges of the two parts. In this case the 'Displace' setting will have no effect because the symmetry of the design means that no center line adjustment is required to achieve the match at both edges (See: 'What is Matching? ').
10. In the 'Section' box of the matching command dialog select 'Grow'. This means the part being matched should increase in size without altering the taper of the part. It will therfore remain a cylinder and be matched to the other main cylinder, therefore becoming of the same diameter.
11 .To execute the adjustment press the 'Match' button. The match section adjustment is done and the match dependency is setup. The main cylinder object becomes the match independent in the design, and the Tee-off becomes a match dependent on the main object. To explore this match dependency in the design see - Exploring Match Dependency . First select the 'Select Match Independents' command. This will select the first object only in the the view because it is independent of all others. Now select the 'Select Match Dependents' command. This adds the second object to the selection set because it is a match dependent on the first object.
12 To see the effect of the match dependency double click on the first object. This should open the Edit Part dialog again on the first part. Type in a new diameter. Select the 'ReMatch' match option at the bottom of the dialog. Close the dialog. The design is rematched so the second object size is automatically adjusted to match the first as before. If this design is converted to a parametric it will continue to adjust in this way as its parameter values are altered.
Variations:
1. At any time during the part creation the ESCAPE key can be used to abort the part creation and the new part is deleted.
2. The center line snap is one way to automatically create a node on the center line of the first object with which to form a link with the end node of the second object. Another way to form the connection would be to first create a mid point node on the first object center line using the 'Edit Part dialog box on the first object. Then when creating the second object use the 'Snap Node ' tool instead of the 'Snap Center Line ' tool.
3. Instead of using matching to size the second part in the design it would be just as easy to type in the same diameter for the second object and ignore matching altogther. This is perfectly feasible for this case but it is useful to have matching dependency set up for other reasons - particularly if the design is to be converted to a parametric design (See: CAD Design Parametrization ).
Recommendations:
Summary:
See also:
1. Tutorial Format
2. Tutorial Index