Ok, do ya put any type of resistance other than a chain. I've seen some where the wooked up a house door side ways and another that had a tarp I guess for wind resistance once the dog runs.

FrostyPaws, how do you get your dogs to run the jenny better than a mill, curious because I've heard some say the contrary of what you just said, that it's hard to get a dog to run all out in a jenny compared to a mill. I have no experience with either a mill or a jenny.