2 weeks ago

The Knitting Network Printer

What can you do with a vintage 1980s knitting machine? You can turn it into a ‘Knitting Network Printer’, that’s what!

Knitting is an ever popular pastime that has spanned the decades, but Sarah Spencer has arguably propelled that craft well and truly into the 21st century, using her ingenuity, a slightly dated piece of knitting equipment, and a Raspberry Pi. Sarah has made a hobby of turning a dusty old domestic knitting machine from yester-year into something very special: a Knitting Network Printer that can produce some rather amazing FOs (that’s knitting terminology for ‘finished objects’ for the non-knitters among you.)

This article first appeared in The MagPi 75 and was written by Nicola King

Knitting: 21st century style

Sarah’s interest in hacking domestic knitting machines began several years ago. As a software engineer, she was keen to investigate the possibilities of marrying current technology with old, and her 1980s Brother KM950i knitting machine (no longer in production) has undergone something of a transformation over the past few years. The original machine came with an on-board scanner to scan knitting patterns, and a floppy drive to back them up. Sarah explains, “By using a floppy drive emulator written in Python and a web interface, I can send an image to the Raspberry Pi over the network, preview it in a knitting grid, and tell it to send the knitting pattern to the knitting machine via the floppy drive port […]. I call this setup OctoKnit, in honour of a more famous and widely used tool, OctoPrint for 3D printers, another popular application for Raspberry Pi.”

Sarah showed off her stellar work at an REA Group hackathon in Australia

Taking several years to perfect, Sarah has made various modifications to her machine over that time, and explains, “With the addition of a motor arm and an automatic colour changer, my knitting is getting very close to being hands-free.” The machine has also had to become much larger since she began tinkering, as Sarah adds that she has “specialised in knitting multicolour work using a double-layered technique called double jacquard which requires two beds of needles.”

Sarah’s approach is nothing less than practical: “I made a thing that can make things, so I need to make something with it, right?” The items that she has made are impressive, including laptop covers and scarves that she sells via an Etsy store.

Her pièce de résistance, however, is extraordinary and on a very different scale… Stargazing: a knitted tapestry.

Out of this world

A huge undertaking that is 15ft (4.6m) in width, this celestial map of the night sky features all 88 constellations across both northern and southern hemispheres. Sarah explains that this heavenly piece of work was “knitted in seven panels stitched together by hand. The pattern on the Raspberry Pi is 21 times bigger than the memory available on the vintage knitting machine, so it’s knitted in 21 separate but seamless file transfers. It took over 100 hours of work, and weighs 15 kg.”

“When I first picked up a Raspberry Pi,” says Sarah, “I never imagined in my wildest dreams what I’d end up doing with it.” Well, she’s done something pretty amazing with it, and whether you’re a knitter, hacker, or simply an admirer of cleverness, knitting never looked so good.