How can I adjust part pattern spacing based on part geometry?

Lachlan_Barrell

I'm trying to pattern this part whose dimensions are subject to change. All the parts should be end-to-end, as in the first attached image. Doing this with a pattern seems logical, but I don't know how to drive that pattern's spacing with a variable defined in a Part Studio. If I adjust the length of the part, the pattern does not update accordingly and the parts have gaps/overlaps in their geometry (second image), rather than remaining in the end-to-end configuration. I am able to assemble them and mate their faces together, one after the other (third image) - but repeating the same action many times makes me think that this is a poor approach.

dirk_van_der_vaart

Maybe try this?

Lachlan_Barrell

dirk_van_der_vaart said:

Maybe try this?

Thanks for the answer, but this isn't quite what I'm after. If the part's dimensions get modified in the part studio, that wouldn't update the configuration table and the pattern would still have incorrect spacing I believe. 

matthew_stacy

@Lachlan_Barrell, you might play with DERIVED parts to see if that does what you need it to.  TRANSFORM using mate connectors and possibly even a dummy part or surface could be applied to define the pattern spacing. 

Share a link to your document (and make it public) if you want more eyeballs on the problem.

tim_hess427

@Lachlan_Barrell - Will the number of components change in the assembly often? I think the "pattern" tool is useful when you want to easily change the number of components in an assembly, but in your case, you may be better of mating the parts manually. If you do this manually, without the pattern feature, your mates will automatically adjust to the changing width. 

There really isn't a way to pass a variable "up" from a part to an assembly. If you really want to use the pattern, you could make your part's width configurable and then use an assembly configuration to set the width. 

Evan_Reese

I share your frustration around this kind of workflow. I hope something cleaner gets implemented eventually. In the near-term, I think the suggestion from @tim_hess427 is the way to go. Make the length of the component a configured variable in the part studio, and the assembly and link them. Here's a quick example. Notice I set the part variable to #length and the pattern distance to #length in the assembly.

lucas_johnson223

Is there any better way to do this now? I seem to have run into the same issue, and can't quite figure it out even with a variable studio.

_anton

One approach is to keep #length in a Variable Studio, then reference that from the Part Studio and Assembly. Assuming that the variable is not driven by the Part Studio itself, of course.

steve_shubin

Lachlan_Barrell said:

… but I don't know how to drive that pattern's spacing with a variable defined in a Part Studio

https://cad.onshape.com/documents/8c0cfad7c0c938dd1492e5f6/w/ce4e2077de9274d5b93f1c3a/e/f55131f50969e4529221f2ab
 
In this document, I am not dealing with multiple parts. But I am dealing with a pattern's spacing with a variable defined in a Part Studio. I haven't thought this through, but you might be able to adopt some of what is in the document in this post.

I also am using the variables to adjust numerous aspects of the groove shape, where the shape can be independently adjusted from one end to the other.

Take a look at what has been entered into the various fields of the various dialog boxes

Notice how the pattern is not running wild off the ends of the part. But rather, look how it adjusts for the size, which you can tell by the horizontal shelving on the left and right sides.

And note how when I change the size of the part, the pattern adjusts automatically

So to @lucas_johnson223, MAYBE there is something in this doc that will help

shawn_crocker

@Lachlan_Barrell
Try this.  The replicate feature combined with @Evan_Reese linear pattern plus feature are a great marriage for this type of dynamic assembly requirement.



https://cad.onshape.com/documents/cf12ccf90d79b8f1dd0e8a50/w/e1ecd84c182cea790ebae04d/e/ec9342d6f652aea45939838c?configuration=legnth=1.143+meter;size=0.254+meter&renderMode=0&uiState=63540f833a5a7b44bd771872