Making a hole in a SketchyPhysics sphere to make a bushing.

[jdc]

Hello All,
I am new to Sketchup and SketchyPhysics.
I do a lot of metal fabrication and operate a CNC Plasma Cutter.
I have always been in the 2D world and would like to make the move
to 3D so I can see my designs/machines before I strike an arc.

I have used the cyl tool in SP to extrude a bar say 2" x 12".
So far so good. It behaves nicely.
I then selected it and hit edit group.
I drew a circle on one of the faces on the end and used push pull
tool create a concentric hole thru the original 2 x 12 bar. The result should
effectly create a bushing.
The problem is that the new piece/bushing does not behave correctly. I have regrouped everything and have selected its statis as a cylinder.
I have selected state as show colision. After doing
so it appears that SP has oriented the collision lines 90 degrees to the actual
bushing/bar. This is driving me crazy. Any help would be greatly appreciated.
Thanks Jimmy

[mptak]

sketchup does not "do holes" that well. Essentially if you want to have a void in something you need to cut it into a set of convex hulls and then group them together. For a rectangular piece with a hole in it you can do this essentially by drawing "rays" from the center of the hole out at regular polar intervals....30 degrees lets say. Each slice is then made into a convex hull and then grouped. There are ways of "faking" it but this is the way to actually make Chris Phillips Sketchy Physics engine do the work.

[Jean Lemire]

Hi folks.

See this SU file for ideas.

[mptak]

http://www.youtube.com/watch?v=wpGpJwlhwck

A demo of one way to make a sphere with a hole...