RWDC

CAD Tutorial: Modeling Wings and Creating Assemblies

Creating a Wing

  1. Make sure you have the E553.pts file. Save it to the directory that you will use as the “working directory” in Creo. This file contains points to define the e553 airfoil. Later you should open the file in a text editor (like WordPad) to see the file layout. The points are separated into three columns for x, y, and z coordinates.
  2. Start Creo Parametric and set the working directory to the folder where you saved E553.pts.
  3. Start a new sketch; name it e553 (this is the name of the airfoil).
  4. Select the “Coordinate System” button. Place the system origin anywhere in the sketch.
  5. Select the spline tool and draw any random closed spline. If it is not closed, you may get an error. DO NOT have any of the spline points on the axes or origin of the reference coordinate system. Doing so will mess up your airfoil sketch. You need a closed spline because the points in E553.pts are for an airfoil with a sharp trailing edge. If you had points for an airfoil with a finite trailing edge (the points on the upper and lower surface at the trailing do not meet), you would need an open spline.
  6. With your spline selected, click the modify button. A new “Spline” ribbon will appear.
  7. Select the “File” in the “Spline” ribbon.
  8. Click on the coordinate system that you placed earlier to set it as the defining coordinate system
  9. Click the “Read point coordinates from file” button (looks like an open folder) and select the E553.pts file. Click open once you have selected the e553.pts file. A warning about an inconsistency in the amount of points will come up. Press yes to ignore the warning and proceed. You should now see an airfoil.
  10. Click the green check mark button to complete the modification of the spline.
  11. When using the airfoil to make a part, it helps if the coordinate system location is defined using strong references. Click on one of the airfoil dimensions; now press and hold the right mouse button until a menu appears. Select “Strong” to convert it to a strong dimension. The dimension will now be a different color. WARNING: When converting to a strong dimension, Pro/E rounds to the default number of decimal points (usually two). This was fine with this airfoil since the two dimensions were 0 and 1. However, if you need to convert to a strong dimension with more accuracy, then you need to change the number of allowed decimal points. Use File>Options and select “Sketcher.” You can now change the number of decimal places for a dimension.
  12. Repeat step 9, but now select “Lock.”
  13. Save your work.

The above process creates the 2D airfoil shape that you need for creating a 3D wing. The section that was created has a chord length of unity. The airfoil above had a closed trailing edge so a closed spline was used. However, if you want to use an airfoil with a finite trailing edge, create an open spline in step 5. Then after step 8, connect the upper surface and lower surface of the trailing edge with a line.

  1. Now we will make a sample wing. Start a new part and give it a name.
  2. Create a blend. Select “Blend” after clicking on the arrow next to “Shapes.”
  3. Under “Options” select “Straight.”
  4. Under “Sections” make sure “Sketched sections” is chosen and click on “Define...”
  5. Select your sketching plane and click Sketch. Use the Sketch View button to view the Sketch plane.
  6. When you are in the sketching view, select “File System”. The Open window will appear. Choose e553.sec and click “Open.”
  7. Click somewhere in the sketching view. The “Rotate Resize” ribbon will appear. Enter 74 for the scaling factor and -2 for the rotating angle. Click the green check mark.
  8. We will base all of the dimensions on the coordinate system at the leading edge of the airfoil. Change the vertical distance between the airfoil and the horizontal reference line of the sketcher view to be 26 with the airfoil above the horizontal reference line. Change the horizontal distance between the airfoil and the vertical reference line to be 53 with the airfoil to the right of the vertical reference line. You can use negative dimensions to switch sides of a reference line.

  1. Click the green check mark.
  2. Under “Sections” enter 300 for the offset and click “Sketch…” Insert another e553 airfoil with a scale of 170 and 0 for the rotation. Change the dimensions so that the leading edge is at 0 horizontal and 0 vertical.

  1. Click the green check mark.
  2. Click the other green check mark.
  3. Save your part.

The above created half of a very simple wing with some dihedral and sweep.

Assembling a Wing and Fuselage:

  1. Have asmfuselage.prt and asmwing.prt in your working directory.
  2. Begin a new assembly and give it a name.
  3. Click the “Assemble” button.
  4. In the “Open” window that pops up select the asmfuselage.prt file.
  5. Click the green check mark to set the fuselage in place.
  6. Repeat steps 3 and 4 but select the asmwing.prt file that you downloaded earlier. DO NOT click on the green check mark. Notice that the wing is way out of place; it needs to be both rotated and translated before it will be in the appropriate place.
  7. Switch to the right view by clicking on the “Named Views” in the “View” ribbon and selecting “Right.”
  8. Go back the “Component Placement” ribbon and click on the “Move” tab. Select rotate and choose 45 for Rotation. Click on the wing and rotate until it is right side up. The wing trailing edge will be towards the aircraft nose.
  1. Now go to the top view. Rotate the wing 180° to get the leading edge facing the right way.

  1. Go to the Placement tab. Click on the center line of the wing (ASMWING:RIGHT) and then click on the center line of the fuselage (ASMFUSELAGE:RIGHT). If a distance appears, change it to 0 in the “Placement” tab. The wing should now have moved.

  1. Now go to the right view. In the “Placement” tab, click on “New Constraint.” Now click on the “Front” plane of the wing (ASMWING:FRONT) and then click on the “Top” plane of the fuselage (ASMFUSELAGE:TOP). If a distance appears, change it to 0.
  1. Rotate the drawing by holding down the scroll wheel until you can highlight the “Top” plane of the wing (ASMWING:TOP).
  2. Click on “New Constraint.” Click on ASMWING:TOP and then click on the “Front” plane of the fuselage (ASMFUSELAGE:FRONT).
  3. If the “Constraint Type” is not “Distance,” change it to “Distance” and enter in the offset as 58. If the wing moves in the wrong direction, put the offset as -58.

  1. Click on the green arrow in the “Component Placement” ribbon. Your parts should now be joined correctly.
  2. Save your assembly.

Notice that there are many ways that you can join two parts. There is no way that we can cover all of them in a tutorial; it is something you have to learn on your own by playing around with different parts that you create and different methods of joining parts. I find the easiest way to place a part is to reference its location by its three datum planes. This is what we did in this tutorial. I find the “Distance” constraint to be the most useful since you can always edit the distances later if you want to move the part. You can also add more datum planes to an assembly to help in joining parts.