The TwitterKnitter2 August, 2013
Back in the mists of time, Paul brought his knitting machine into TOG. We had a play with it, examined the punchcards and the reader, and had a conversation along the lines of “hey, wouldn’t it be cool if* we could knit our own patterns instead of using these cards? We could even knit tweets and stuff**.”
Fast forward to the Friday night before the Dublin Mini Maker Faire. The knitting machine now has a contraption bolted to it. There are 24 servos, wood, laser cut plastic, string, electronics, an Arduino and a laptop. The machine has just knitted the letter A for the first time in its 40 years, and I am dancing around the hackerspace with glee. It works! It actually works!
What’s going on here? The laptop is running some Python that searches for tweets with a particular hashtag, and lists them. When you choose one, it creates a black and white image of the text and sends the image data to the Arduino. The Arduino detects when the knitting carriage is pulled across (via a cunning microswitch wedged into the punchcard advancing mechanism), reads the next row of image data, and operates the servos to pull the plastic dibblers up or let them drop. In essence, the hardware is just simulating the punchcard and the knitting machine knits the pattern as usual.
We took the TwitterKnitter to Dublin Mini Maker Faire along with many other TOG projects. At the start of the day, the knitting still had a few glitches: stitches here and there stuck on the wrong colour. Some of them were caused by a loose string, others by stuck parts on the machine itself, but by the end of the day the text was coming out perfectly. I was delighted. We knitted all day until we ran out of wool…
The great thing about the hackerspace is that if your project is blocked by a missing part or some problem, chances are someone can help you out.
- Paul brought in the machine in the first place.
- Tríona showed me how to work it (and how to unjam it).
- Paul brainstormed ideas to control the pattern.
- Robert lent me some servos to test the idea.
- Tríona laser cut*** 24 dibblers and bought half of the servos.
- Gary and Paul provided electronics advice.
- Jeffrey lent me an Arduino Mega.
- Cheryl lent me a laptop to use at the Maker Faire.
Each of these represent something that would normally have held up progress; waiting for parts, or shopping, or bashing at a poorly understood problem. Instead, someone wandered over and offered parts or expertise, and suddenly the project was moving again (and I was a little wiser, too). Thanks all!
Now then. Wouldn’t it be cool if we could knit pictures?
* This is a dangerous start to a sentence.
** Unbeknown to us, there was another Twitter Knitter project in 2010. And as usual when I have a project idea, I find that my nemesis Becky Stern has already implemented it, but her machine was already electronic.
*** Took a look at the wooden prototype, went to work the next day, designed them by eye from memory, and handed me the laser cut bits a few days later. I thought, there’s no way these are going to fit, and they were perfect. Clearly she missed her calling as an engineer.