topic Re: Unable to pattern a shell design - program always crashes in 3D Part & Assembly Design

Unable to pattern a shell design - program always crashes

IS_9417601 — Mon, 20 Mar 2023 00:52:53 GMT

Hello, I have not used CAD in a while and was trying to copy a plant tray I had at home to get back to ease myself back into the program; however, I have run into problems. Perhaps I am using the pattern feature incorrectly, but when creating a new pattern based on simple extrusions and a chamfer, the program runs quite slowly.

As a result of this, when I try to create a shell pattern creo always crashes and is unable to complete the action. Does anyone have any advice for me please? I have attached the file.

Thanks.

Re: Unable to pattern a shell design - program always crashes

tbraxton — Mon, 20 Mar 2023 01:45:00 GMT

You are using an educational license so most here will not be able to open the file. Post a picture of the plant tray and someone may offer a method to create the geometry.

If you need help with your specific model, then post pictures of the geometry and the model tree so we can see what you are doing.

Re: Unable to pattern a shell design - program always crashes

IS_9417601 — Mon, 20 Mar 2023 02:15:46 GMT

Thanks for the reply, I did not know this was a thing. The design is a 13x13 cell plant tray. I've attached two renders plus the model tree of what I currently have so far.

In render 1, the cell bottom centre nearest to the user is what the tray is meant to look like. Unfortunately I am unable to "shell" the other cells though. Interestingly I am able to perform the procedure manually once, but when I try to do it manually/through pattern a second time, the program will crash.

Thanks 🙂

Re: Unable to pattern a shell design - program always crashes

tbraxton — Mon, 20 Mar 2023 03:18:34 GMT

Here is one way to do this very quickly using two bodies and patterns. The first pattern is of the center point of each "cell". The second pattern is of a body that defines a unit cell. The cell body is used to cut out the tray web plate and then the cells are merged to the plate. The only "trick" is to select all of the open faces in the cells when creating the shell feature. This shell could be reference patterned with a more sophisticated modeling approach.

See the video for process and features:

(view in My Videos)

Re: Unable to pattern a shell design - program always crashes

IS_9417601 — Mon, 20 Mar 2023 03:21:47 GMT

Is there a way to do this in creo 6 without bodies? Otherwise I will look into updating my creo to the newest version. Thanks!

Re: Unable to pattern a shell design - program always crashes

tbraxton — Mon, 20 Mar 2023 04:04:28 GMT

Yes, it can be done without multibody functionality. You can create it with construction features (surfaces) to create the shell of each unit cell in the solid model. If you create a group consisting of the closed quilt needed to shell a cell and a solidify cut using this quilt, then you can pattern the group to hollow out each unit cell.

This is one example of how to do it. This shows the group of construction features used to create the shell of a cell. Extrude 2 forms the solid cell and then the construction geometry is used to "shell" it out using a cut.

Before the solidify cut you have these quilts, one of which will cut the shell thickness of a cell. Copy the outer surfs of the shell, offset to the thickness needed, extend the open side to clear the plate and then solidify the quilt.

Pattern this group using reference pattern:

Re: Unable to pattern a shell design - program always crashes

kdirth — Mon, 20 Mar 2023 12:41:06 GMT

The issue with how you have started to create your model is that when trying to pattern the shell feature the program is trying to shell the entire body again. I would pattern the shape of each cell then shell the entire model.

Another option, that is newer and based on an old work around, is to use geometry pattern. For a geometry pattern, you select all of the geometry that defines the feature on the model then select geometry pattern. This is also a lighter model as the values and calculations for each member of the pattern are eliminated as they are simply copies of the shape.

Re: Unable to pattern a shell design - program always crashes

MartinHanak — Mon, 20 Mar 2023 16:09:20 GMT

Hi,

my tip ... 3 Extrudes, 2 Identical Direction Patterns.