I’m very new to Sketchup. My apologies if this is an elementary question.

Suppose I model a simple dinghy: 2 sides, bottom and stern, along with all the resultant compound curves. I now want to unzip the intersections and unfold the model in order to cut the 2-d shapes out of plywood.

Or seen in reverse. Suppose I model all the 2-d plywood shapes needed to make my dinghy and then wish to join the edges together to model the resulting 3-d shape. How would I go about doing this?

All advice gratefully received. :)

Hello, I think the best way to come up with the Sketches is by use of a software. The ideal one is the AutoCad 3D and the AutoCad 3D its very simple and you can model all the 2-d plywood shapes needed to make my dinghy and then wish to join the edges together to model the resulting 3-d shape.

This is a pretty hard one with sketchup. It doesn't do "unfolding" very well. Especially when it's something like thin plywood bent over a complex shape. I've played with several other CAD packages and don't recall seeing anything that might do better. You can easily model thin "shells" in Fusion 360 but I'm not sure how you would flatten it after that. I would probably start with modeling the support structures. I'd add a few intermediate ribs to then put a skin of polygons on. Your polygons can be unfolded relatively easily to approximate your actual skin pieces. I assume that you would then trim the skin material to fit on the actual frame. I'd probably try to keep the skin shapes pretty simple so trimming is easy.

Now, one thing to consider is Fusion 360 has a new feature called sheet metal that allows you to define the actual sheet material and specify some details like K factor, bend radius, relief and such. Don't know if it can do curves but might be worth playing with. You might be able to make it work by defining a shape, unfolding it, trimming, refolding, ... in an iterative process to get closer to what you want. Might work but will probably take a lot of trial and error.

Sketchup, while relatively easy to use and get your head around, its unfortunately not very powerful in terms of autocad or autodesk. Most of the "big boy" softwares have "slice" or silhouette

For this type of project, I would clone each panel and paste it to the side on its own, thus allowing you to have both available right there. Simple as ctrl+C then ctrl+v

so like youre making a "box" of each panel, just copy and paste each object to the side and there you have it. edit: I understand you're looking to do curves, and the process is identical here, you can manipulate the copy pasted objects independently of the main project.

edit: adding a more relevant image.

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