3D Printing & Parametric Design

Creating 3D objects with Grasshopper

Selene & Lilli

Day 1: Brainstorming

3/23/23

Our object requirements: Voronoi + Flexible Object.

We decided to create a lap desk with a flexible Voronoi sponge base and wooden top made with the cnc printer. The sponge squares will be 8inx6in and have a locking mechanism to create a total of area of 16inx12in.

Day 2: Grasshopper and prototype print

Mesh prototype in Rhino and the components in Grasshopper

We followed a Youtube tutorial to create the voronoi cube. Unfortunately, the mesh yielded a bunch of naked edges, so we added a Weaverbird thicken node, which made it slightly thicker, but fixed that issue. We also had to flatten the unify normals component to invert what the voronoi was applied to.

Changing filament to flexible TPU

We set the onloading filament to the wrong type, so we had to unload and load it again.

Day 3: Prototype reflection and reiteration

When slicing the first protype, the supports were acidentally set to extruder 1 instead of extruder 2, so the entire thing printed in TPU, and we couldn't remove the supports. The print was still pretty squishy though. We are currently problem solving for complications when attempting to slice our final piece.

Day 4: Failed print and redesign

The printer had an error with extruding the TPU and was only able to print a few layers before having a "Material error". We then worked on scaling up the size of the sponge (although we will not print that until we have a successful prototype) and making the protoyupe thicker in rhino.

Day 5: Redesign

The print was semi successful, however the sponge was too thin and the outer walls fell apart. We are trying printing again with a higher infill (80% instead of 20%) and walls twice as thick.

Model with thicker walls

New print settings

updated nodes in Grasshopper

We ordered a translucent pink TPU to print our final model with, but it was 1.75mm, not 2.85mm which the Ultimaker requires, so we're unable to use it.

We plan to use these acrylic scraps to lasercut a tulip design to inset in wood.

This prototype wasn't quite as squishy as we wanted and was still pretty fragile on the edges where the print wasn't as thick. However, the middle was super dense and made it stiff, probably because of the high infill.

We reduced the number of the voronoi cells to make room for increasing the thickness of the walls. We're going to try 2 more test prints of this wall with 40% infill and 20% infill.

Day: Many prototypes later...

The photo on the left represents four unsuccessful prototypes. The problems range from failed structure to lack of flexibility. The farthest block on right was successful structurally - we decreased the number of voronoi cells and increased the density. However, it proved to have no "squish" at all. The edges were plenty flexible, but the collumns in the middle connecting the cells were too thick to allow squish.

Movie on 4-21-23 at 1.41 PM.mov

Full prototype #5 was by far the most successful. The structure was what we wanted, but the squish was minimal. As seen in the video, it takes a good bit of force to cause the cube to bend in any way. Although this prortype fufills the project requirements, we wanted to go for something squishier

3 newest (kind of failed) prototypes

same number of cells, 2% infill

somewhat squishy, but still very stiff in the middle

increased number of cells, 10% infill

doesn't break easily, but pretty flexible, even in the middle—we're going to try a full print of this

same number of cells, don't remember infill

somewhat flexible, broke in the the middle (kind of brittle)

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