[Animats]

Shopbot has a closed loop stepper on some models [1], but Tormach says they don't.[2] Tormach just has a big enough stepper and enough gear reduction to avoid missed steps by brute force.

[1] http://www.shopbottools.com/mProducts/ShopBotdesign.htm [2] https://www.tormach.com/technical_questions.html