Noob needs help. - mapping a sketch to a hemisphere..

Hi,

Im not sure my terminology is correct, but will try and describe what
I need to do as best as possible.

I have a hollowed hemisphere, with a wall thickness of 10mm, I wish
to cut a pattern through the face of this, but I need the edges of the
pattern that will form the cut to be at an angle (coinciding with the
centre of the hemisphere) rather than vertical. Is there a way to map a
sketch to the surface of my hemisphere, so I can just cut-extrude my
pattern through the hemisphere?

Cheers,
Scott.

 

You might be tempted to use the Wrap command, which will do what you
ask, but only on cylindrical and conical surfaces.

You're probably limited to a projected curve, split line or trim, all of
which do a straight projection rather than a wrap. Here's one thing I'd
try to get a radial cut:

- make an offset surface of the outside of the hemisphere at 0 distance
- use your sketch to trim the offset surface
- insert, cut, thicken

There are a lot of possible problems, but that's one place to start.

 

I would take the following steps:

1) Draw a 3d sketch from the origin of your sphere to the point you
want to be the center of your cut profile.
2) Make a plane at the endpoint of that line using the "normal to
curve" option.
3) Sketch your cut profile on your new plane
4) Make a sketch of a single point at the origin and create a cut loft
from your previous sketch to this point..

This should work for most simple profiles.