#1 By: Martin Selby, August 21st, 2013 08:51
We're working on a contract which involves cutting 800+ holes of varying Dia. in 1 metre Dia. Sphere.
We've got a wrap in DWG format which we've used for marking out the holes in a sample
which worked really well.
We now need to translate this wrap onto an actual sphere in Rhino to give to the manufacturer
to enable him to laser cut the holes.
#2 By: Mitch Heynick, August 21st, 2013 08:56
How is the "wrap" mapped to the sphere? Does the mfr have a 5 axis laser? What kind of data do they need to be able to cut the part?
#3 By: Martin Selby, August 21st, 2013 08:59
They have a 5 axis laser & are wanting an IGES file, the actual orientation of the wrap on
the sphere is not important at this stage.
#4 By: Mitch Heynick, August 21st, 2013 09:11
Yes, OK, but is the "wrap" a 2d pattern that has to be mapped onto the sphere somehow, or is it in 3D? Is what they want is a 3D IGES with the cuts as curves in place on the surface?
#5 By: Martin Selby, August 21st, 2013 09:18
Yeah, a 2D wrap & the manufacturer would like a 3D IGES solid with the actual cuts in.
#6 By: Al Worth, August 21st, 2013 09:25
Have you looked into Rhino Panelling Tools? (Google "Rhino Panelling Tools")
#7 By: Martin Selby, August 21st, 2013 10:38
I'm not sure if paneling is the way to go, it's a non-uniform grid of holes.
#8 By: Mitch Heynick, August 21st, 2013 11:16
Well, the most important thing is how the 2d geometry is going to get "wrapped" to a spherical surface (especially near the poles). If you do a straight UV NURBS mapping of a flat pattern (like FlowSrf) everything will get bunched up near the poles.
So somehow you need to get the distribution of points on the surface that is non-UV. Grasshopper has a component that does this, but if you distribute the points on the surface and then put circles around them, there is no easy way to prevent collisions.
My feeling is you might need to create a spherical Voronoi and make your circles stay within the cells...
#9 By: Willem Derks, August 21st, 2013 11:32
Could you be more descriptive on what this wrap is? Is it an Autocad type functionality or an image file?
Is the initial DWG file correct in the placement or do you need to remap a new pattern in Rhino?
I have modeled the project below with varying diameter holes. In the end I even send axis and diameter information to directly use for the programming. It might be I have some scripts from that project that can be of help to you. You can also contact me in a private message of you do not want to disclose the model in the public discussion.
#10 By: Mitch Heynick, August 21st, 2013 17:38
I know this is probably not what you want, but since I was fooling around with this, here are a couple of GH defs for making random but more or less evenly distributed holes on a sphere. One does just the curves, the other carries it through to a wall thickness solid. The second is pretty slow to update... Just for laughs...
Hmm, new form for Swiss cheese?