I have trained many colts on a machine, I have a PRO-CUTTER, which is a pully system but mine does have a cow body, but alot of people just use a flag, they are extremely easy to set up and if you look on EBAY you can find a good deal on them! It takes a time or two for colts to get used to them, but we have both broke colts on them and tuned up show horses and they work incredible.