Modern knitting machines have a large rack of latch hooks, one hook for each stitch in a row. It can knit and purl, and even be programmable, but it’s not scalable. You can’t increase or decrease the number of stitches in a row, unless you do it manually, like this guy does for the shoulders of his sweater. If someone made a machine that could knit like a human, with just two hooks, and all of the stitches held on a cord, the machine would be able to make as many stitches as the cord was long, and cord could be made arbitrarily long. Plus, one could coerce it to knit twice in the same stitch for an increase in row size, and to hook adjacent stitches together for a decrease.

How it works

Knitting is essentially pulling new loops through loops on the previous row. The mechanism has a hook to pick up a loop from the previous row, another hook to pull a new loop through, and a third hook to put down the new loop.

Challenges I ran into

Jordan's suitcase was lost by Air Canada until Saturday night, so for the beginning of the hackathon we were doing everything with wires and duct tape and no tools. We also ran into a snag when we realized that the motor we used for the yarn loader was not a continuous servo. We thought a stepper would be too heavy, so we disassembled a servo to transform it into a continuous servo, but this did not give us the precision we needed. Thankfully Jordan's suitcase was delivered, and we used his dremel to mount a stepper for the yarn loader.

Accomplishments that I'm proud of

Tony did all our electrical work with only 2 months of electrical experience. What a boss!

What I learned

Bring everything you think you might need for a hardware hack to the hackathon, and don't fly Air Canada.

What's next for Knitwear Printer V2

Knit a row Knit a row in reverse direction Make a scarf


  • NYC Resistor (special thanks to David for teaching me how to use the 3D printer and Widget for helping me gather parts for the project)
  • The original Knitwear Printer team Michael, Oleh, and Bryan from MHacks 5, who helped design the mechanism and 3D printed parts (
  • Adam from Apes in Space, Ryan from Toptal, Eric, and many others for mentoring us throughout the hackathon

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