Parametric Offset in a Sketch

russell_dunlop

I have designed a machine, whose width is configurable, such that the tines on it work themselves out to the correct amount automatically etc.
I am coming undone, however, on the implementation of an adaptive pattern on the front plate.
As shown in the screenshot, the pattern radiates out from a center point, rather than being a linear pattern.
Consequently, I am unable to do a linear sketch pattern on the part, and am instead using the offset tool.
The issue with the offset tool is i can't define a number of lines to create, meaning i can't parameterize the pattern.
Is there a solution to this? Preferably it wouldn't involve me making a custom FS function😅, but if there is no other choice then that's what it will have to be I suppose.

PS. Sorry, i can't share the document as it is proprietary.

NeilCooke

I think the easiest thing to do here would be to create the pattern at the maximum size, then fill in the slots with an extrude. You might have to make the plate huge, then cut it down afterwards.

David_YL_Nguyen

You could also look into how to drive your sketch with variables in a pattern. This Tech Tip could be helpful for that: https://www.onshape.com/en/resource-center/tech-tips/tech-tip-how-to-use-variables-in-patterns-to-vary-features

The smallest cutout, towards the outside, should probably have it's own sketch in that case.

EvanReese

@russell_dunlop I favor the approach @David_YL_Nguyen is proposing. You don't need to do the patterning in the sketch itself. Instead you can (with some clever setup) pattern the sketch feature and the extrude cut feature in a way that it updates flexibly. Here's an example of what that can look like.