CAD Battle #2 - March 2026 (4 Dimensional Modeling Competition)

Now that's a provocative title, huh?

If you've followed my recent posting of featurescripts and my general posting around the forums, you'll know that Onshape's simultaneous sheet metal engine is one of my favorite things about the software and that it drives most of the projects and products I put out in one way or another. The ability to see the folded and unfolded states at the same time is so much more intuitive than other sheet metal systems in other software I've used. You might then assume that sheet metal fabrication itself is also my jam - and while partly true, that's not the full story. The thing that actually interests me about sheet metal fabrication is that you can take a model in a complex folded configuration, flatten it out into a different state to prep it for manufacturing, and fold it all back up in reality to match the original model and get highly complex parts via some forming operation that would be difficult or impossible in other manufacturing methods. There are other manufacturing processes that this also describes, here are a few examples:

Laser Cut Tube Bending

Kerf Bending Plywood

ACM Origami

Foldable 3d Prints

I tried to find a video link but couldn't find one that demonstrated the use case well enough.

These are all manufacturing methods which deliver extra complexity in the final product and make it easy to fill out a larger 3d volume with fewer steps in fabrication, less material needed, and one single part performing the job of many. But there's something else common among them all: modeling for any of these things is hard. Or at the very least, tedious. So you're substituting fabrication labor for modeling labor. That can be okay if you've got a product that manufactures at high volumes but I'm all about the 1 of 1 unique parts, and I like solutions that can scale that way. The other commonality among them is that the flattened or unrolled states of these flexible parts are 3 dimensional themselves, and cannot be represented with pure 2d linework alone. Even the example of the ACM has 90 degree bevels cut into the sheet which, while possible to represent as a .DXF, would abstract away the true geometry of the parts and result in inaccurate renders or worse, potentially allow for you to send out bends past that 90 degree angle that won't fit correctly when machined. Onshape has plenty of solutions for getting a 2d unwrap of geometry, but comparatively few solutions for a 3 dimensional deform. I'm looking to explore that landscape with this competition.

🚩The Goal

This 4D modeling challenge is an open ended hunt for procedural workflows that can allow you to create complexity in your non-sheet-metal parts without introducing it to the modeling stage, and simultaneously without compromise for the render. Show me your best foldables and flex on the other competitors.

🚫 Ban List

None this time. All features are fair game, but there are likely many you should steer away from. There's a Flex feature in the wild that might seem like an attractive proposition for this competition but it's probably a trap for more complex builds.

🏆 Criteria for the Winner

This competition has no explicit target model. Instead we are looking for:

1. Folded and Unfolded States of Geometry: The obvious. This competition is about showing off parts which are intended to be produced to fit a final product state but need to be unrolled or flattened for manufacturing. I suppose you can also show intermediate stages of manufacturing model for bonus points, but only the 2 are necessary.
2. Geometric Parity Between States: The geometry of the unfolded state must have corresponding geometry in the folded state. Something like @NeilCooke's new Unfold Frame feature, while an excellent tool would not pass this criteria because the final folded state of the frames post-manufacturing should show the bend geometry. Presume you need to create a render of the final parts, and missing geometry would be inaccurate to the final product. (We won't actually be doing renders but that's an example of why this would be necessary)
3. Complexity of Geometry: The unfolded manufacturing state of your parts must be more complex than a simple 2d sheet. Surface Flatten and sheet metal workflows are impressive but this competition is specifically an exploration of parts that must be exported in 3 dimensions, or at least 2.5.
4. Practicality of Modeling Practice: There are lots of ways you could painstakingly achieve manufacturing models by pure sketch horsepower and drafting diligence but this is a workflow exhibition and blatant featurescript bait of a competition so these kinds of solutions will be rated less highly than ones that use other solutions to achieve their geometry.
5. Document Creation Date: This being an exposition type competition without a target model to reference, you could theoretically submit any existing document as an entry. To level the playing field your submission must be created after March 1st this year. You can use existing workflows but you gotta start from the same starting line as everyone else. This includes any Derive shenanigans.

Submissions will be open for the month of March and then the first week of April we'll take a forum poll of submissions for whichever submission impresses us the most. The best one will once again get mailed a Shapey.

Hall of Fame:

Winners of previous CAD Battles: 

• Winner of CAD Battle #1 - January 2026 - @EvanReese