week 8 - Open Source Hardware
Exploration of the open source hardwares in the textile field.
How to take advantage of digital fabrication and open source technology to come up with an open source machine for knitting, weaving and invent new techniques.
Hacking a machine
For this assigment I worked together with Wei Cheung and Gerantina Hoxha. We chose to automate the movement of a manual weaving loom, shown in the image.
First we studied the movements needed to create a textile with this machine, which are four: half of the threads are moved up and half down, creating an empty space. Then, a thread is passed from one side to the other through this empty space. This thread must be pushed and tightened with a comb. After that, the up and down threads are reversed creating again the empty space in which the combed thread is passed again.
As a team we decided to automate the up and down movements, which could be done by servo motors. We used an existing open source loom that was laser cutted and assembled by Thu and Adriana, following the instructions in this link.
We wanted to convert the circular movement of the servo motor helix to a straight up-down movement. As a first trial we used cable ties to act as needles. Since they are made of a flexible material, the bottom part could bend following the servo motor movement, while the upper part could move the thread up and down, guided by a vertical channel. For that we added a vertical support in the structure and attached a straw to function as the channel.
We were concerned about the number of threads we could use in our machine to create a textile. We have as many as possible we decided to keep half the rows stationary (level 0) and connect only half to servo motors which would move to level +1 and -1 to form the gap needed to pass the weaving thread. This decision was taken to use a minimal amount of servo motors and also because the movement of the helix didn't allow the threads to be close enough as needed.
We tested movement of the "needle" connecting the servo motors to the Arduino and using two buttons which would move the helix 180 degrees, back and forth, connected as illustrated in the fig 8.4. The code worked well as shown in the video in the fig 8.5.
To continue the idea, we designed the automation with 8 servo motors, which would result in a total of 16 threads. To sustain the movement of the needles we designed horizontal guides as illustrated in the image 8.6. Ideally we designed needles that could be laser cutted but due to the lack of time to finish the assigment we continued to use the cable ties as needles.
We screwed the servo motors on the wooden support, measuring the distance between them so the blades would not clash each other. We passed yard threads through the needles using different colors to identify the stationary and the movable ones.
We connected the 8 servo motors to the Arduino, ground to ground and VCC to 5V, and used pins 5,6,7,8,9,10,11 and 12.
As a result me manage to automate the up and down movement with buttons as our initial intention, altough there is a lot o room for improvement.
The results can be seen in the video below.