The World Cup is here again! The geometry of the football itself is always a little interesting. What panels make up the surface? Looking at the ball closely, I could see that it was one shape tessellated 6 times – a weird cube as it were. So, how can we model this up in SOLIDWORKS? Will we need complex surface tools? Weird lofts? No! We use a split line or two, copy a couple of surfaces and pattern, pattern, pattern.
Step 1: Draw a spherical surface section 220mm diameter.
This is the standard size of the competition ball, at least as far as Google would tell me. I drew a semicircle at the required diameter and created a mid-plane revolved surface over 90 degrees.
Step 2: Create a ‘quarter-square’ face
If you examine pictures of the ball, you will see that it is made of just 6 pieces. The faces are also rotationally symmetrical every 90 degrees, so we will start with a simple trim.
Step 3: The Split
Now comes the ‘fun’ bit. We need to create the shape for the actual face. We only have to do a small section, but we will make sure it matches up as nicely as we can.
We want a 2D sketch; it is a simple stepped design. I just need to ensure that the centre line passes through the origin and that the two shorter horizontal lines are equal. Two dimensions and we are done.
Next for the Split command – it is on the Direct Editing Tab.
We are then left with 3 surface bodies.
If all has gone well then the model should look like this:
Bước 4: Làm dày
Chúng tôi muốn làm dày ba bề mặt. Điều này đòi hỏi ba hoạt động riêng biệt và bạn cần phải đảm bảo rằng hộp kết quả hợp nhất được giữ rõ ràng. Sau đó chúng tôi sẽ có ba phần thân (được thể hiện bằng các màu khác nhau để làm rõ):
Step 4: Thicken
We want to thicken the three surfaces. This requires three separate operations and you need to ensure that the merge result box is kept clear. We will then have three bodies in our part (shown in different colours for clarity):
Step 5: Move the Split Bodies
Now we need to rotate the coloured bodies 180 degrees to form the section of the panel. The Move/Copy bodies command is also on the direct editing tab of the Command Manager. You can choose the edge between the red and grey parts in the centre to use as the axis of rotation.
Then we will use the Combine command to Join the bodies together.
Step 6: Finish the section
Now we need to finish our section, since we have a quarter of the panel we can just create a simple circular pattern. We will pattern the body and not the features:
Step 7: The finished ball
Now we just need to create an assembly of 6 panels. Insert the first instance at the origin and then a second and mate in place.
Conclusion/Penalty Shoot out
So, there we have it: the Telstar 18 Ball. If we tweak the shell thickness we could get an accurate weight for the ball as well, or perhaps we could use Flatten surface to find the cut shape required for the flat leather sheet. You could also add decals and generate the image at the top of the page.