Lattice by shelling

[Chris3]

Before I open up an idea on this does anyone know of a way to shell a part but replace the shell with a lattice? Or convert the remove shelled volume to a body so I can use that for a lattice?

[Dale_Rosema]

I sat in on a presentation at the recent PTC User's conference about Additive Manufacturing. They were presenting ways to do this and then to optimize the pattern to reduce the need for structural supports. You may need to have an add-on to do this. I do not use this where I work.

[Dale_Rosema]

https://community.ptc.com/t5/Creo-Parametric-Tips/Creo-Additive-Manufacturing-Tips-Techniques-Session-Recording/ta-p/820811

This may have been the demo used.

They start with an open body and a shell body if I remember correctly.

[Chris3]

They aren't using a shell feature in that demo.

[MartinHanak]

Hi,

see attached model (Creo 7.0).

[Chris3]

This is close, but you had to create a surface to cap the shelled area. That is easy to do when you have flat surfaces. Its harder to do with more complex geometry.

[tbraxton]

The demo provides the methods that should be readily extrapolated to use with the shelled geometry. Can you post your model or at least a picture of your shell geometry? You can use a copy feature to capture a closed shape of the shell before any holes are in the shelled geometry. Apply the lattice to the unblemished continuous closed copy of the shelled geometry core quilt.

It sounds like you may have a geometry that is problematic with respect to reducing the lattice to practice but without seeing it I am not able to offer much specific input on how to deal with it.

[Chris3]

To be clear, I know how to make lattices and I am not having a problem making them.

The question was if there was a technique that people are using to make the subtracted volume into a body that can then be used for the lattice. @MartinHanak's technique of using seed and boundary surfaces is probably the best thing we have right now.

It would be convenient if the shell command had a button to turn the subtracted volume into a body that could be used for the lattice without needing the steps of the seed surfaces (Creo could do that for the user in the background). I will submit an idea for this.

[tbraxton · Accepted solution]

@Chris3 The documentation regarding the definition of a lattice region (domain) is lacking. It is confusing and needs clarification. The lattice tool supports what I think you are asking for already, see the enclosed video for a trivial example of how to do it.

Taken from this link:To Define the Lattice Region (ptc.com)

The term "closed" here is misleading in the context of surface modeling in Creo. Closed volume in the context of Creo surface modeling (core or ISDX) has always been presented to mean a watertight quilt without any gaps or openings.

"The selected surfaces, quilts, and datum planes should create a closed volume. The arrow should point toward the inside of the volume."

[MartinHanak]

Result of my test ... procedure described in video works for following model (Creo 10.0), too.

[Chris3]

I will mark this as the solution, @MartinHanak should get credit here too. I understand this solution but it still doesn't provide me completely what I am looking for.

In Martin's Example and in this example the "top" surface that you click after the seed and boundary are flat planes or in Martin's example below one continuous surface.

In my situation the "top" surface was made up of multiple surfaces. So to make this work currently, after I shell, I need to do the seed and boundary and then I need to select all of the "top" surfaces to close out the "closed area". The seed and boundary doesn't always work with multifaceted "top" surfaces because it doesn't know where to stop (or maybe I just need more practice). My use case is probably a small sliver of the pie since a lot of geometry people make fall into one of the buckets shown as examples in this thread. I haven't had time yet to create an idea for a one click shell to body but at least in my use case it would have some clicks.