I doubt it would be difficult to make. You can buy the knitting machine on amazon. They usually have a handle you can crank unless it is electric. Just attach a turbine to the handle.

you could, but the (original) website is from 2009...so probably not enough interest to keep that up. The old link is dead: https://windknittingfactory.bigcartel.com/

I'd be surprised/impressed if the knitting machine itself was a DIY project.

I know this is art, but to be overly reductive, it's the same as buying your electricity from a wind farm and using it to power your knitting machine.

I'm disappointed it doesn't make socks.

Every HNer knows your startup needs to maintain a moat /s