Here is a youtube of a sock knitting machine in operation. they are fun, but can have a steep learning curve to making a heel & toe successfully. After you learn, it becomes smooth sailing. Never thought I would have more than one machine, but its like SMAD, they start multipling! Mine are all antiques, but I know of 2 companies that are making new ones......1 in New Zealand and 1 in Cape Girardeau, MO.
https://www.youtube.com/watch?v=8uvL_KUq7Pg