Roombas don't use any servos. Just a couple of regular brushed DC motors. They do sell a blank chassis for classroom stuff: https://edu.irobot.com/what-we-offe

Roombas don't use any servos. Just a couple of regular brushed DC motors. They do sell a blank chassis for classroom stuff: https://edu.irobot.com/what-we-offer/create3 https://edu.irobot.com/what-we-offer/create3