How can I simply create a repeating pattern?

kyle_miller

Hello all,

I've been working for the last few days, pulling my hair out, trying to create a simple repeating pattern that I can place into some open slats in a grill I'm creating.

I tried the linear pattern, but it gives no indication of alignment. What I mean is that it doesn't specify any snap lines or points, nor does it indicate your current angle relative to the piece you're repeating. As such, things end up out of line, and I have to go in point by point to snap everything together. This is not only tedious, but often times will cause lines to start splaying off in all directions or red lines to consume the sketch.

With the linear pattern function incapable of producing the effect I want, I also found a link in the forums to a Feature Script called Fill pattern. While it seemed like the right tool for the job, I cannot get it to work for the life of me. Not sure if my pattern is too complex or what, but a 0.01" change in the distance either creates too many instances (>2,000) or less than 2. Either way, I cannot seem to make it repeat my pattern.

As such, I have taken to copy-pasting the pattern, aligning everything, defining everything, and it is not only excruciatingly tedious in nature, but is also pushing my CPU up around 40% @ 4.38GHz, so every line I tweak takes 4 to 5 seconds to load, and when you're talking thousands and thousands of lines....

Therefore, I once again must return to the brain trust to see if someone out there in OnShape land knows of a way to repeat a pattern quickly & accurately, or alternatively how to group sketch entities so that it is not so computationally abusive to copy and paste.

To give you an idea of what I'm trying to do, here are a couple of images.
Grill w/ open slats (no pattern filling them).


The insane number of definitions.



The pattern close up.



Finally, the extruded end product...with a long...long...long way to go.


Thanks,
Kyle

konstantin_shiriazdanov

hi, try this approach - less sketching, more high level operations
https://cad.onshape.com/documents/f10204aa10d2bbfffb901440/w/2b4f74ba225afb77672c06aa/e/807059c9e67a066915005c1c

create several patterns like this as separate parts and then union or sutract it with your main shape. the advantage is that you may have one simple sketch with only 6 lines in it per one "ray" and it will work in wide range of parameters. you can even try to parametrize it to refference one sketch for all the rays

mahir

As @konstantin_shiriazdanov suggested, try utilizing booleans along with linear and circular part patterns. Here's an example similar to your design.

https://cad.onshape.com/documents/57acdfaae4b005c413ed9b6f/w/3fd585a46d3af1b3ba413c53/e/87b3fb5a4cc4836d6b5384d0

kyle_miller

Hey guys,

Just wanted to say thanks for the help. I downloaded both files and tinkered around with the features and settings to try to figure out exactly how you did what you did. In both cases the path to victory utilized a whole host of features I never knew existed. As such, I'm going to have to go in again and see if I can replicate what you did. My CAD skills a paltry, so it will probably take me a while, but I really appreciate all the help, files, and most importantly proof that it actually is possible. Now all I have to do is make it happen.

Much appreciated once again,
Kyle

konstantin_shiriazdanov

hi, try this approach - less sketching, more high level operations
https://cad.onshape.com/documents/f10204aa10d2bbfffb901440/w/2b4f74ba225afb77672c06aa/e/807059c9e67a066915005c1c

create several patterns like this as separate parts and then union or sutract it with your main shape. the advantage is that you may have one simple sketch with only 6 lines in it per one "ray" and it will work in wide range of parameters. you can even try to parametrize it to refference one sketch for all the rays

mahir

As @konstantin_shiriazdanov suggested, try utilizing booleans along with linear and circular part patterns. Here's an example similar to your design.

https://cad.onshape.com/documents/57acdfaae4b005c413ed9b6f/w/3fd585a46d3af1b3ba413c53/e/87b3fb5a4cc4836d6b5384d0

owen_sparks

Hi guys.

Interesting problem and great solutions guys.

Another point if I may.  Please don't be hesitant to ask for help if you're struggling.  Give it a go first, but in general if it's taking you more than 10 minutes to build reference geometry then there is almost certainly an easier way.   Lots of helpful folks here who have probably gone through what you're banging your head against and are willing to jump in and help.

Oh and as ever a link to the document is always helpful.

Cheers,

Owen S.

John_P_Desilets

 kyle_miller

A quick tip that you can use to help see problem areas in your model is the "show regeneration time" tool. This excellent tool shows you what features take the longest to regenerate. This allows to you isolate the computationally stressful feature so you can plan for a better design approach.

Here is the link to our help documentation for the show regeneration time(s)
https://cad.onshape.com/help/#feature_list.htm?Highlight=time



 konstantin_shiriazdanov
mahir     
 owen_sparks     and the rest of the Onshape community is here to help make you successful! Please reach out to us any time you need assistance. 

kyle_miller

Hey guys,

Just wanted to say thanks for the help. I downloaded both files and tinkered around with the features and settings to try to figure out exactly how you did what you did. In both cases the path to victory utilized a whole host of features I never knew existed. As such, I'm going to have to go in again and see if I can replicate what you did. My CAD skills a paltry, so it will probably take me a while, but I really appreciate all the help, files, and most importantly proof that it actually is possible. Now all I have to do is make it happen.

Much appreciated once again,
Kyle