Project Overview

Problem:

The state of the art method for bamboo construction requires power tools and is very time intensive. Given the intention of constructing bamboo homes in Haiti (see the "Affordable Bamboo House" page for details), there is need for a tool that requires less time and electricity.

Solution:

I created a manual bamboo processing tool that splits and cores the bamboo at the same time. I then created a novel way to bind the bamboo together into an interlocking section so that it doesn’t require the notching and individual wire wrapping that was very time consuming in the original roofing prototype. This interlocking bamboo section can be oriented horizontally to act as a roof, or vertically to act as a wall. Therefore, an entire house can be built using the pieces made from the bamboo processing tool. Additionally, given that 80% of ground water in Haiti is infected with cholera, I additionally designed a mechanism to collect rain water from the roof of the house. I believed that this would incentivize locals to adopt the house, which was important given the foreign nature of bamboo houses in Haitian communities.

Video of the first bamboo splitter prototype in action!

Final Prototype of the Bamboo splitter in action!

Design Process

State of the Art Technique

To first understand the problem, I researched and tested the state of the art technology for bamboo coring and splitting.

A jig is used to cut the bamboo in half (1), and a chisel is then utilized to remove the core of the bamboo (2). A saw is needed next, to create notches in the stalks (3). The bamboo can then be latched together with a perpendicular piece of wood, and the construct can be bound with wire (4).

Alternative Splitting Method

A manual splitting device exists, but it splits the bamboo into many small pieces that would not be suitable for the design of the house. Additionally, it does not core the bamboo.

Preliminary Designs

At first, I thought it would be most efficient to core the bamboo first, and split it later.

1. I split the end of an aluminum pipe and created sharp edges, and used it to remove the nodes of the bamboo. Unfortunately the hole was too small, and the splitter device bended during use.

2. I modified the shape of the splitter to make it stronger and broader. This succeeded in removing the nodes, but it cracked the bamboo in the process.

Further Iterations

Given the results of my second iteration of the splitter design, I decided to make a tool that could split and core the bamboo simultaneously.

1. This first idea succeeded in splitting the bamboo and removing part of the nodes, but it did not completely core the wood.

2. After widening the component that cut through the nodes, I landed with a tool that could effectively split and core the wood at the same time. However it was challenging and time consuming to center the tool, so I kept iterating to optimize the design.

Modular SolidWorks Prototype

In SolidWorks, I created a prototype whose modules could be added, removed, and rearranged to optimize function in a variety of bamboo pole diameters. I machined and assembled the parts out of aluminum and spring steel.

Final Tool Prototype

The final product would be mounted on a sturdy pole, and would be inserted into the bamboo from above. The product consists of four key components:

1. Tip: The tip pierces the nodes and begins the coring process.

2. Centering Springs: These spring steel pieces center the tool in the bamboo, allowing it to core and split the bamboo evenly.

3. Splitter: The blades on either side of the tool split the bamboo in half as the user pushes it down.

4. Corer: This component completely cores the bamboo, so that water cannot accumulate and cause rotting in the final construct.

Bamboo House Prototype

A 20’x30’ bamboo house made from split bamboo using my splitter tool would use only 260 twenty foot poles. It costs $300-400 to purchase the raw bamboo poles, treat them with a sap displacement method, and build a concrete footer. Not only does this house hit the ambitious $300 price point, but it is 5% of the $8,000 price to build a concrete block house of that size in Haiti. The house also incorporates running potable water in order to persuade the Haitian community members to accept this unconventional building material.

Bamboo Roof and Wall Design

Oriented horizontally, the bamboo section becomes a roof. The interlocking modular design is important for allowing water to flow down the bamboo. It also shows why the bamboo needs to be cored, in addition to being split.

Oriented vertically, the interlocking bamboo section becomes a wall. While rain can’t penetrate the walls, air can still flow through the walls making the entire house “breathe” which was a big concern for the Haitians due to the sweltering heat they experience. The twine for binding would be replaced with bamboo fibrous rope, making the entire house completely sustainable, and able to expand and contract at the same rate as the wood itself.

Water Filter

The attached water filter is made from a cored bamboo pole, and uses pebbles, sand, and bamboo charcoal as the filtration mechanism. It is gravity fed from rain water collected from the roof.

Bamboo Processing Tool