Hi fellas. These are a lot of great suggestions, and I'll give several of them a try. I thought, probably incorrectly, that backlash was the problem since there is less on the craftsman 109, and that lathe cuts and cuts without breaking tools. I'll try tightening up the gib screws and reducing the rake on the tool. I ran it upside down and in reverse on the Jet 1440 at techshop, since it has a di6 chuck mount and is safe. I've unscrewed a threaded chuck once, and no matter what anybody says, I am not trying that again. Even at only 200 rpm, things happened fast and can really go south. The tool is held in a purpose made block and is close to the hold down bolt so there is less of a lever arm and better rigidity. I found that things improved if I manually held the cross slide back as I was feeding it, but this isn't a good solution. Looking at the above picture, the cut outs have a lot less rake than my tool. I'll seek their geometry. I think there's a picture of the parting tool in the craftsman section. I'll see if I can find it and link it. Thank you for all the suggestions.