The mechanical training dummy in Dune always fascinated me. When I read Dune as a kid, the scene on Caladan in which Paul´s training dummy is described, very much defined Paul as a character for me. It made clear that he did not grow up like a normal child but instead lived under constant threat of being assassinated, always preparing to be ready and fight for his live to his best ability. Not much later, shortly after their arrival on Dune, the scene with the hunter seeker happens and confirms this impression.

I found these three designs for the dummy on https://dune.fandom.com/wiki/Dune_Wiki

The left and middle image are pretty close to the design described in the book if I remember correctly. While the left image shows the dummy in action, with lots of different rotating, hacking and stabbing blades, the middle image shows the dummy in standby, with retracted blades. Both designs were made for the movie adaption by Lynch.

The right image is an alternative approach, deviating from the design described in the book but in a way that fits canon well in my opinion. Suspensors are common tech in the Dune universe, just think of the omnipresent glowglobes that light so many scenes in the story. Therefore, sticking a suspensorglobe into a traing dummy seems like a pretty obvious thing to do. The person standing next to the “Suspensor Drone” is Gurney Halleck. The art is by Mark Zug, created for the Dune Collectible Card Game by Last Unicorn Games.