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Unread 11-04-2006, 20:32
John Gutmann John Gutmann is offline
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Re: ULTIMATE CHALLENGE

Quote:
Originally Posted by Greg Needel
OK so i really don't want to do this because i know that it will take some time but i came up with a "simple" way of doing it.



If you create a sphere in the cad of your choice, then make a datum plane tangent to the sphere. make a new sketch of the pentagon or hexagon shape on the centerline of the sphere and extrude the outer portion away, you will be left with a pentagon/hexagon rod with compound curves on the ends. extrude away so you are left with a pent/hex block with 1 curve edge and 1 flat. If you then chamfer the edges to the proper degree (not sure what it is), and fillet the corners of the part you will have a building block for the ball. You will need to make both a pent and a hex part. Create a new assembly, and assemble the pieces together......done deal.

now that i typed that out i may try it when i have a few seconds. The only choice now is the software (pro-e, inventor, or solid works).


Greg

That isnt the correct geometry, on a real soccer ball they cut out pentagons then they are curved. They are not cut away from a curved surface.

I would say to do it maybe make a sphere
make a work plane in the center, then offset 2 work planes from it in either direction along one axis. Make an angle work plane on the same axis and repeat. Then to actually cut it out make a sketch on each work plane, slice graphics then project geometry the edge that you get from slice graphics.

First off about the offsetting of the work planes. You need to go measure a soccer ball with a piece of string to find out the distance between the to parallel edges the penta/hexgons. then use math to find out what that dimension is if that line - line distance is put on an arc and then find out how far apart the edges are.

When your done with all that^^

Make a new sketch facing all the work planes and then project geometry the 5 / 6 lines onto the one sketch, then extrude cut the sphere away.

lastly chamfer the inside edges and fillet the outside ones for ease of assembly. When I have access to auto desk for a while in study hall I will model it up


OR....after a second thought....

Using somewhat of that method^^calculate the small circle you can fit that all into(penta gon / hexagon. then figure out the depth of that sector(or is it a section i cant remember the term). Makes a sketch>revolve it. Then on the flat part draw the hexagon from the calculated distances and extrude then do finishing steps.

Last edited by John Gutmann : 11-04-2006 at 20:36.