I'm thinking of investing in a knitting machine, mainly to make illusion knit scarves. I understand there are programmable knitting machines out there, but are they just for intarsia? Or can they cope with knits and purls needed for illusion knitting?
Knitting machines come in a wide variety of types, with vastly different capabilities. You can do illusion knitting on a knitting machine with what's called a garter carriage (something only Brother ever produced, so only Brother machines can do this).
It is possible to do illusion knitting on a single-bed knitting machine without a garter carriage (instructions here
), but it basically involves knitting a bunch of stitches, undoing them, and manually reforming them. Very time-consuming! It would honestly be faster to knit by hand.