topic Re: Is variable length extrusion in a parametric pattern possible? in Fusion Design, Validate & Document Forum

Is variable length extrusion in a parametric pattern possible?

rcautodeskGGQ52 — Thu, 17 Jul 2025 16:52:01 GMT

I am modeling a case to hold my machinist parallel set and have built it to be fully driven by user parameters. That way I can change the number of parallels (pairs) in the set, their size (width/length/thickness), the spacing between them, etc. in the future. I have the box bottom fully built out and everything is working perfectly when I vary the parameter values. Now I am trying to model the parallels themselves and am running into issues getting that to be driven from the same parameters.

I would like to define a sketch for the first pair of parallels (smallest one) in the set, repeat that pair "NumParallels" (user parameter) times (using rectangular pattern), then extrude each item in the pattern a variable amount equal to something like "MinParallelHeight + (ParallelHeightIncrement * <# in pattern>)". I built a small test bed design (attached) to experiment with (uses the BaseLength to drive # of parallels) but I haven't figured anything out yet that works since access to something like "# in a pattern" doesn't seem possible (that I have found so far) and/or I can't figure out how to select all items in a pattern such that varying the number of items down/up works. I can manually go through each item in the pattern and extrude them using my formula and a hard-coded # (how I got the "desired result image" attached) but that all falls apart as soon as you start messing with the number of parallels.

I also experimented with defining a sketch plane that extends between the leading edges of the first two parallel pairs and then extruding up to the plane but that doesn't fit the bill either since the tops of each parallel pair are now slanted and I have the same problem with selecting everything in my pattern.

Is what I want to do possible?

Re: Is variable length extrusion in a parametric pattern possible?

davebYYPCU — Fri, 18 Jul 2025 03:05:37 GMT

Slightly different preparation will do it.

Let me know if you get stuck,

Might help....

Betreff: Is variable length extrusion in a parametric pattern possible?

g-andresen — Fri, 18 Jul 2025 09:04:29 GMT

Hi,

I have created a pattern of parallel pairs on the basis of @davebYYPCU

(view in My Videos)

günther

Re: Is variable length extrusion in a parametric pattern possible?

rcautodeskGGQ52 — Fri, 18 Jul 2025 18:34:25 GMT

Very cool Dave. I hadn't thought about sketching the parallel pair tops along a rising path and then extruding down to the base. But since the base surface/plane is constant that makes perfect sense. You even managed to work in some Pythagoras 😂 I messed up some of the dimensioning/constraints in my test bed (parallels weren't properly "anchored" to the base) but after correcting that I can adjust the base size (and thus the number of parallels) willy nilly and everything works perfectly. Exactly what I needed. Thank you!

Betreff: Is variable length extrusion in a parametric pattern possible?

rcautodeskGGQ52 — Fri, 18 Jul 2025 18:38:38 GMT

Thank you Günther. I was actually lazy with my test bed file (as well as my original case project) and modeled everything as parallel pair rather than individual parallels. My NumParallels user parameter would be better called NumParallelPairs but I didn't for some reason. I may change things up to model the individual parallels though so this may still prove useful. Thank you again for the ideas.