topic Re: Cellular array rib creation in 3D Part & Assembly Design

Cellular array rib creation

tbraxton — Sun, 10 Dec 2023 20:14:37 GMT

Creo 7

I am looking for an automated way to create a cellular array of ribs and have run into what seems to be a limitation with trajectory rib functionality. The first pic below illustrates an example of what I want to create but I am not able to use the projection of the patterned hex curves in the sketch for a trajectory rib without manually selecting each hex.

I am able to generate a pattern of cells that "should" be available for use when defining a sketch for trajectory ribs. So far, I am not able to select the cell array with a pick box or intent reference selection. Am I missing something with sketcher selection or in the projection tool within sketcher?

Is there a better way to approach this from a modeling standpoint if I want it to be more automated? Using a fill pattern, I can generate the array from a single sketched hexagon and a few feature relations. It would be nice to leverage that and generate the ribs based on this pattern.

I need a way to select all of the cells using "all curves in feature" or similar when defining the sketch for the trajectory rib for this approach to work.

Re: Cellular array rib creation

Michael — Sun, 10 Dec 2023 20:23:11 GMT

You could do this with creo lattices. Requires AMX though. It does this and more.

Re: Cellular array rib creation

tbraxton — Sun, 10 Dec 2023 22:12:08 GMT

I have a superficial knowledge of AMX capability and while it may create the cells quickly, the ROI is not likely good for just this problem. Assuming the cells were created using AMX features, can those features be parametrically modified without an AMX license, e.g. change the wall thickness of the cell?

I am looking for methods to automate this using core Creo modeling (without extensions other than advanced assembly). The parts in question run 10 million pcs/year and are not made with AM. The model in the first pic was built using a method not involving trajectory ribs and is "automated" but CPU resource intensive due to pattern regeneration times. We have methods of dealing with this limitation but are exploring alternatives.

Re: Cellular array rib creation

tbraxton — Mon, 11 Dec 2023 12:53:23 GMT

Creo 7 test case model for reference. I am trying to use the cell array to generate trajectory ribs in the shell.

Re: Cellular array rib creation

aputman — Mon, 11 Dec 2023 15:30:14 GMT

The way I would do this would be based on the method of patterning in this video. It's a patterning of quilts versus features, which significantly reduces the regen time. You will need a larger bottom "plate" to solidify against but that is easily removed after pattern is created.

https://www.youtube.com/watch?v=6d2eIY6CLY4

Re: Cellular array rib creation

aputman — Mon, 11 Dec 2023 15:45:37 GMT

Most of the rounds can be added as well, using this method. I would share the file back to you but I'm using CREO 8.

Re: Cellular array rib creation

tbraxton — Mon, 11 Dec 2023 15:58:33 GMT

We are well versed in using quilts to speed up large patterns and the current approach to deal with this is using quilts to create the cells and reference patterns to complete the ribs. The issue with this method is bounding the cells where they intersect the perimeter of the "shell shape". This is something that trajectory ribs handle quite well as long as there is a closed wall around the entire perimeter of the solid when the ribs are created. If the trajectory rib can be exploited it would likely be more robust to geometry changes in the shell.

Quilt based array for fully drafted and rounded cell geometry.

Re: Cellular array rib creation

MartinHanak — Mon, 11 Dec 2023 17:37:23 GMT

Hi,

I didn't think much, I just tried it.

Re: Cellular array rib creation

tbraxton — Mon, 11 Dec 2023 18:38:30 GMT

@MartinHanak thanks for the model. What you had to do to pattern this was exactly why I submitted this query. It requires the manual selection of patterned curves to be used in a sketch for a trajectory rib. I am looking for a way to select all curves in the array for use in the sketch which may not be possible currently.

From PTC documentation on sketch for trajectory rib:

Sketch one or more lines, splines, or arcs to define the rib feature trajectory. The sketch can contain any number of open, closed, and self-intersecting curves.

Re: Cellular array rib creation

MartinHanak — Tue, 12 Dec 2023 18:22:53 GMT

@tbraxton wrote:

@MartinHanak thanks for the model. What you had to do to pattern this was exactly why I submitted this query. It requires the manual selection of patterned curves to be used in a sketch for a trajectory rib. I am looking for a way to select all curves in the array for use in the sketch which may not be possible currently.

From PTC documentation on sketch for trajectory rib:

Sketch one or more lines, splines, or arcs to define the rib feature trajectory. The sketch can contain any number of open, closed, and self-intersecting curves.

Hi,

this is my last reply ... during testing I found that following sketch created inside Trajectory Rib definition is not valid. This means that it is useless to try to put all the hexagons into one sketch.

Re: Cellular array rib creation

tbraxton — Tue, 12 Dec 2023 18:59:14 GMT

Agreed, in Creo 7.09 it is not working. Based on my interpretation of the documentation it should work and appears to be a bug/not to spec. I have opened a call with support on this.

Re: Cellular array rib creation

tbraxton — Wed, 13 Dec 2023 13:58:40 GMT

@Michael Can you apply a 2.5D hex cell structure using AMX to mimic the geometry I posted? I ask because I was online with PTC support yesterday asking if this could be done and they were not able to get the geometry into the model which I provided to them. They are still investigating. If it is easy and quick I am interested to see how AMX implements adding this type of rib.

I would do it myself but do not have AMX license.

Re: Cellular array rib creation

MartinHanak — Wed, 13 Dec 2023 19:47:34 GMT

@tbraxton wrote:

@Michael Can you apply a 2.5D hex cell structure using AMX to mimic the geometry I posted? I ask because I was online with PTC support yesterday asking if this could be done and they were not able to get the geometry into the model which I provided to them. They are still investigating. If it is easy and quick I am interested to see how AMX implements adding this type of rib.

I would do it myself but do not have AMX license.

Hi,

in uploaded video you can see single lattice feature.

Re: Cellular array rib creation

tbraxton — Wed, 13 Dec 2023 19:57:24 GMT

@MartinHanak Thanks for posting that. It certainly looks like it works nicely. Can drafts and rounds be added to the lattice geometry? Can the lattice feature dimensions (cell size and rib thickness) be edited without an AMX license once the feature is in a model?

Re: Cellular array rib creation

MartinHanak — Wed, 13 Dec 2023 20:13:59 GMT

@tbraxton wrote:

@MartinHanak Thanks for posting that. It certainly looks like it works nicely. Can drafts and rounds be added to the lattice geometry? Can the lattice feature dimensions (cell size and rib thickness) be edited without an AMX license once the feature is in a model?

Hi,

1.]

Lattice features are related to 3D print, Maybe because of this it lattice cannot add draft to faces of hexagonal shape. Also it cannot add rounds to edges at the point of contact with the bottom of the model.

2.]

YES, lattice feature dimensions (cell size and rib thickness) can be edited without an AMX license once the feature is in a model.

Re: Cellular array rib creation

tbraxton — Thu, 14 Dec 2023 12:57:47 GMT

Thanks to @MartinHanak for confirming that the AMX lattice feature does not appear to be a replacement for trajectory ribs. If drafts and rounds cannot be applied to the lattice features, then it is not useful to design molded or cast parts.

Since the AMX module is made for 3D printing process this is not that surprising.