OpenNest is a Grasshopper plugin with tools for unrolling, packing and of course nesting curves directly inside your definitions. With OpenNest, enhance your configurators with price computation, bills of materials and stronger links with your manufacturing process.
What Is Nesting And When To Use It?
Nesting is an important step for optimizing fabrication processes. As an example, take a chair made of several plywood pieces assembled together.
In order to fabricate this chair, CNC machines will need to cut its individual pieces from the same raw material. During this operation, the goal is to use as few plywood sheet as possible, so as to optimize cutting times and reduce waste.
A nesting algorithm will find a way to place as many individual pieces as possible in a minimal space.
The different pieces of this plywood chair were efficiently nested in order to use a single plywood sheet for manufacturing. (credit: Chairfix Junior)
CNC Machining is perhaps the most common fabrication process where nesting is important. Other applications include packaging, printing and even cutting fabric and composite materials. Efficient nesting has a direct impact on consumers because it strongly influences the price of the end product.
Nesting And Mass Customization
In the context of Mass Production, nesting only needs to be done once for tens of thousands of products. In that case, one could manually prepare the nesting at a relatively low cost, compared to the volume of production.
On the other hand, customizable products need a different nesting solution for each configuration. In that case:
Automating the nesting process is a key step on the way to mass customization.
As a consequence, a nesting algorithm is also a powerful tool to include in a product configurator.
OpenNest: Free Nesting Tools In Grasshopper
Petras Vestartas developed OpenNest as a way to finally bring a reliable and affordable nesting algorithm to Grasshopper. Indeed, OpenNest is completely free. Petras is also planning to open source the code in the future.
The plugin consists of a few useful Grasshopper components. The main one, simply called OpenNest, performs the nesting algorithm. The others consist of various helper components. Those components make it easier to unroll, project and pack curves in a plane before nesting them.
The inputs of the nesting component will not feel like a surprise to the designers who are familiar with nesting algorithms. First, specify polylines for the containing sheet of material, as well as a set of objects for nesting. The plugin supports curves of course, but also meshes and breps. Then, play with a series of options regarding tolerance, minimal spacing between elements, number of iterations of the algorithm, and more...
Combine It With Other ShapeDiver Features!
Of course, nesting is only useful if the results can be used for manufacturing. For that purpose, the ShapeDiver plugin contains export components to various formats, including DXF.
You can also specify additional properties such as names, layers and colors using the ShapeDiver properties components. Furthermore, exported files can include annotations using Fabtools, for example. Fabtools is also supported on ShapeDiver.
Finally, you can send data to the ShapeDiver API regarding the results of the nesting operation. For instance, the nesting density, material waste and number of sheet of material can be used for pricing calculations and to start planning the manufacturing steps.
Demonstration On ShapeDiver
Check out this very simple demo where panels defined by a Voronoi graph on a freeform surface are projected to a plane and nested in rectangular sheet. The exported DXF files include file names and different layers for the sheet and the nested parts.