I am curious if a flat shape can be deformed around a sphere. I saw this bell image and that is what made me think of it. I am using MoI v4



In Moi

Hi Don, it is possible to deform a flat shape onto a curved surface using the Transform > Deform > Flow command, there is some information on it in the help file here:
https://moi3d.com/4.0/docs/moi_command_reference8.htm#flow

However it's kind of difficult to deal with areas where things pinch down to a single point. The regular sphere surface that you draw from Draw solid > Sphere has "pole" areas where the sphere surface's control point net collapses down to a single point and that will cause the flow result to also pinch down there as well.

- Michael

Thanks for taking time to reply.

Hi Don, I was experimenting a bit with this, I think it will help if the flat base surface for the flow mapping is also a revolved surface with a pole in it as well like this:


That way the center of the object will map to the bottom pole of the sphere and the outer edge of the flat base surface will map to the top edge of the sphere, with this result using Transform > Deform > Flow:



If you use a plane surface (for the base surface in Flow) that only has 4 corner points instead of a radial control point layout it won't map well because an edge in the 4 corner point plane will map to the sphere pole and it will get squished down a lot.

For this case a revolved base surface matches up to a revolved sphere better.

One note - the revolve command replaces revolved horizontal lines with 4 point plane surfaces because those can get special treatment in booleans and fillets so to make a revolved flat disk you have to revolve angled line with no end cap to make an open cone first and then squish it flat.

- Michael

that's cool michael

Great tip, thanks Michael! (nod)

Thanks Michael!

For an experiment this was interesting, but I think it would just be easier to make the 3D bell in a different fashion, since just trying to figure out what might derform just right seems to be too difficult - for me anyway.

I always appreciate how you take a personal interest in user questions!

Hi Don,

You perhaps already know that ref but, just in case, here's the link to How Bells are Made -How it's Made :
Jingle Bells machine making starts at 1'15" .

https://www.youtube.com/watch?v=DfJC-0s8qIo

Like you, I also think that there is a lot of testing to get a good looking result.
And the resulting blank shape would probably not suit press forming process, 3 steps press mold bending.

Where you thinking of designing blanks for a mold to make some jingle bells ?

Happy Holidays !

Thanks for the link to the video. I always enjoy seeing the manufacturing process.

No, I was not thinking about making bells. I just stumbled across the image I shared in the original post and wondered if MoI or one of the other CAD apps I use could form it. I thought that if any could, it would be MoI.

Hi Don,

Here are 2 other interesting links to Jingle Bells making, this time traditionally forged :
https://www.youtube.com/watch?v=N2mamR4CBKo
https://www.youtube.com/watch?v=kZRVbCWbTOU

I don't think it would be possible to use the blank used as ref to get the bell shaped in one step in Moi as it doesn't take into account the 2 steps process to make the bell.

The 3 Youtube refs, either by machining or handforging, treat the bottom and the "petals" part separately, in order to prevent stretching the "petals" while constricting the center part.
In the Flow process, the blank is stretched all the way to the top and gets elongated.

We would need to take the "plasticity" of the metal blank into account.