#39 - A New Project

Leaf-Inspired Trunk Pt. 1

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When I was picking which idea to work on next, I was looking for something that would build on what I’ve learned while also challenging me. That way, I’d get to refine old concepts while also exploring new ones.

The project I chose was a composite trunk for my Saab 96. The old concept I’ll refine is the natural composite recipe that I came up with during my last project. And the new concept I’ll explore is a leaf-vein inspired stiffening structure.

The idea came from Bcomps' powerRibs™, which I stumbled across when I was looking for technical linens to buy. I thought their idea to mimic leaf veins was fantastic. I’ve always been a sucker for biomimicry -- especially when it comes to composites. My gut feeling is that there’s still a world of unexplored possibilities within composites, and that biomimicry might help us break out of our limiting, metallic frame of thinking.

So how is this project different from the powerRibs™? The powerRibs™ arrange the stiffening “veins” as a grid. I’m going to take the concept a step further and replicate the branching in leaf veins.

Why could this be interesting? One of the advantages of composites is being able to tailor the material to align more of its strength in a particular direction -- something not possible in metals. That means less of the material is dead weight. However, that ability to tailor the direction hasn’t really been true for stiffness. 

The common solutions allow you only to change the overall stiffness, not how forces travel through your part. With these leaf veins, I might be able direct those internal forces and, because of that, carry material (weight) only where I need it. In other words, I might make a lighter part. If none of that made sense, don’t worry. I’ll explore these concepts more thoroughly later in this series.

Why do I want to lighten the Saab? Because I intend to race it in rallycross and a lighter car is a faster car. (And I need to maximize the power -- 65hp from the factory, 50 years ago.)

The Plan

To make a part, I’ll first need to make a mold. For the last project, I used epoxy and fiberglass. This time, I’ll try to use something more natural or, at least, more pleasant to work with. Once the mold is sorted, I’ll get into small scale tests to try to understand the advantages and disadvantages of this idea compared to more traditional solutions. And finally, I’ll use what I’ve learned in those small scale tests to make a full size trunk and install it on the car. Of course, along the way, I’ll be sharing my successes and failures and everything I learn from them.

The Goals

As I mentioned in my six month review, I’m going to list out my goals so I don’t hold myself to a different standard a few weeks from now. The goals are intentionally achievable. I’ll be satisfied if:

  1. I come up with a mold making process that allows me to be my usual messy self. (In other words, it uses relatively non-toxic materials.)

  2. I get a good understanding of the pros/cons of the leaf vein concept.

  3. I make a trunk with veins. It doesn’t have to be the lightest possible solution; just something that opens my mind (and hopefully yours) to new ideas.

Let’s see how I do!

Corrections? Questions? Comments? I’d love to have your input. Leave a comment, email me at surjan@substack.com, or find me on LinkedIn.

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