In the past few weeks I’ve been doing two main things:
1. Prototyping the housing module at a larger scale (1:4 instead of the previous 1:20).
2. Material sourcing for both, the module and the construction drone.
I decided to work on a 1:4 scale because, first, it will allow me to spot structural inconveniences with the housing module second, because I couldn’t find any place suitable for me to be able to work at real scale and third because the prototyping price at this scale is still “reasonable” for my current resources.
In the beginning of february I started working on the scaled up module. The material of choice this time was foam core board because it would resemble the lightness of large scale panelling filled with insulation foam and it’s also remarkably fragile, so if there were any weak spots, they would be very easy to find. You can see the prototype in the images below.
In this prototype I was able to observe something that will save me lots of headaches in the future. Some of the seams (the ones to both sides of the largest panels and the central seams of the roof panels) have a very large surface area and, in the smaller scale prototypes it was undetectable, but in this prototype I could clearly see that they will need to be structured with rigid elements. In the expansion process there’s no visible problem, but when the modules are to be compressed for storage, the larger seams have too much freedom, allowing the panels to “eat” them in random folds, creating deadlocks in the compression mechanism. To correct this I’m going to have to add rigid elements within the seams to reduce their freedom and guide them straight to where all materials need to be when the module is compressed.
Another interesting behavior of this module is that of the side doors. By having their own hinges, their expansion is not consistent, so for future prototypes I will have to lock them to the surrounding panels in order for them to work harmoniously with the others and help to strengthen the lower panels that might be compromised if they move by themselves and try to compensate the force of the other panels levering against them.
For the next prototype, I will also add the corner male/female locks so that the module can fit together with others like itself. The mechanism will be very simple (see image below) and will take advantage of the fact that the construction drone already counts with a lifting mechanism. In that scenario, the drone only has to run into a previously assembled module, lower the new one and release, and the two modules will fit together like a glove. In order for this mechanism to work properly, the front and side panels need to have 4 female hooks (one per corner) and the back panel will have 4 males. We’ll see more clearly how it works in a further iteration, and when it does, I plan to make the locks conductive so that electrical networks can be created by just putting the structures next to one another.
In terms of the material sourcing, I’m focusing in two main areas right now: finding key electrical/mechanical components for the drone and finding the right panelling material for the modules. In the electrical part, I already found some 12VDC geared motors that will be able to get the job done for the drive train, lift and drill mechanisms and a power supply strong enough to power them all and the microcontrollers that may be necessary. On the panelling side, I’m still inquiring around the five boroughs in order to find exactly what I need and for the right price, but that should be done by the middle of next week.
My next steps will be to acquire the plastic for the module panels and the drone’s chassis, design the drone around the new components, test the power supply with the motors and the logic simultaneously and build both, the drone and the module’s new iterations as fast as possible.