Modular Support Structure

To support a recovering community I wanted to make a rapidly deployable structure that could provide rapid aid for as long as they needed.

CAD (Fusion 360)

Computer

Internet

3d Printer

Laser Cutter

Plywood

Basswood

PLA+

Hammer

Drill

Knife/Blade for deburring

Before starting the design and even research processes, I first made a clear set of criteria that I wanted the design to accomplish.

-Must be able to effectively provide a wide range of aid to the community

-Must be modular

-Must be rapid to deploy and fairly easy to construct

-Must be easily moved or disassembled

-Must be able to last for as long as the community needs

Originally to achieve the modularity and rapid deployability that I wanted, I was planning on designing a universal "pod" that would be a renovated storage container. I liked this idea because there's already tons of infrastructure surrounding storage containers and they are designed to be stacked very easily.

Then, after researching, I realized that if I wanted to make openings in the walls of the containers that would be necessary to make them habitable, the structural integrity of the container would drop significantly.

So, eventually I found the answer, a better one at that! I discovered an open source project, WikiHouse. Wikihouse offers a de-centralized approach to construction where sheets of plywood or OSB are machined on a cnc router network spread across the world, anyone with a router can make the panels. The panels are then assembled into boxes that are filled with insulation. Once the assembled boxes are shipped to the building site, very little hardware is needed to assemble the structure because the skylark boxes use interference fit bowtie joints that are hammered together with a mallet.

This system was perfect, you can fit many of these pre-constructed panels in a 40ft shipping container to make multiple small structures to fit different needs. They also offer robust wind resistance as they are designed to make lasting 1 story houses, sheds, and now are being developed for 2 story houses.

Within the WikiHouse Ecosystem there's the Skylark 150, 200, and 250, these numbers refer to the thickness of each box (mm). I went with the Skylark 150 because it's plenty strong for what I need and going with the thinner option will keep weight and cost down.

I also visited the WikiHouse GitHub page (https://github.com/wikihouseproject) to download all of the wall, floor, opening, and roof blocks I thought I would need.

I also needed to think about a foundation to sit these structures on. A typical concrete foundation would take too much time, be too expensive, and too long term. So I landed on ground screws for a foundation. These work great because I can have multiple pods on the same level plane on uneven terrain without having to do any grading.

At this point I had to think about the size of each unit. I knew I wanted a 1:2 aspect ratio to achieve maximum modularity. I eventually settled on a 5m x 1.8m x 2.4m internal volume. These dimensions worked well with the WikiHouse system and meant that I could fit over 5 unpacked units in a shipping container.

If I wanted to be able to connect multiple units together, then I would need to design a standardized mating feature that ideally uses no metal hardware.

I started with just importing one floor and two walls so that I could experiment with the best and cleanest way to make an assembly with this system. I found that using mirror and pattern functions with rigid groups would save the most time.

Pretty quickly I had something that was beginning to look a lot like what I had envisioned. At this point I had decided that a 1200mm opening on each 5m side and a 600mm opening on the 2.4m sides would give the structure the most modularity. I also designed these openings with a WikiHouse opening frame that provides a way to add a door for a more long term structure, however in my design to keep the weight down I opted to use a curtain in the openings.

After the walls, floors, and openings were done it was time to tackle the roof. To use the 1deg flat roof that I wanted to use, I had to make custom panels on the ends (the grey ones) that would interface with the WikiHouse roof blocks.

I had to modify the outer floor panel to add a custom panel that correctly supported a Ground Screw. I then mirrored this across the unit/pod.

The corner screws were very simple to mount as they just used the existing edges of the floor to support the mounting plate.

After making a bare bones structure I made a concept layout for a medical pod and a shelter pod. The Medical pod uses two fabricated medical beds that I found on Grab CAD. The bunk bed is a model I also found on Grab CAD that uses a cot like mattress and 2"x4" lumber in its assembly which I liked a lot because it's a realistic model that could be made rapidly. Both use a generic storage rack to store supplies. I'm happy with how well the building size accommodates essential supplies.

I was happy with everything, however there was still one thing I had to solve. If I wanted multiple pods to be able to connect to make one big structure, I would need to find a way to connect them. I was struggling to find a way to solve this problem in CAD and decided that the best way to do it would be with a scaled prototype in front of me. I would need to make two models though in order to test connecting them. I designed a simple prototype that is made up of four laser cut panels and a 3d printed roof. The prototype was made at 5% of the unit size.

I made exported the panel sketch as a DXF and laser cut them at a local technical college's maker space. I used Basswood and Plywood.

I 3d Printed this simplified roof that uses compliant tabs to locate and connect to the structure.

The WikiHouse Notches at the edges of the panels scaled really well and made assembly much easier.

I drilled two holes in every corner of the panel. In one hole I embedded a magnet that would mate with an opposing magnet in the mating panel, this made for locating the panels relative to one another easier. Then the second hole is for a bolt that takes the actual loads of the two structures.

At this scale the magnets work great as locating features, however I don't know how scalable they would be.

I truly believe that this is a proof of concept for how powerful decentralized manufacturing is as a whole and how it can be applied to make a true difference. It would be awesome to see a more refined version of this actually be used and deployed at scale and I genuinely hope this idea can help people in some capacity.