JUKI AMS Texprocess Movie. - YouTube
Take a look at the machine shown at 4:33. They have taken a standard sewing machine that has a top shaft and bottom shaft that is usually linked via timing belt. If the rotation of the bottom shaft is just slightly off, it won't sew right. I am amazed at the speed obtained and accuracy that has to be there.
Is this pretty standard for electronic gearing or is there something special going on? I have several applications a machine separated from top and bottom shafts would be an easy solution.