The Dogs vary in length relatively, each Catcher having long, short, and medium length Dogs. The riveted construction eliminates the possibility of missing set screws by loss or neglect.
The object is to get the basket over the junk and cut a core. To do this, run the basket in the hole a few feet above the fish and put the pump on. Circulate with full circulation and clean the hole. Slack off to the fish and try to wash it clean. Pick up five or ten feet, then cut the pump back to minimum circulation so you will not pump junk to the outside of the hole. Lower the basket slowly while rotating until you are over the fish. You may have to pick up and start several times before getting over the fish. Sometimes you can tell when you are over the fish because the rotary will level out and the basket will rotate smoothly. When you think you have the fish inside the basket, apply the weight that is needed to make a hole and cut a core (one or two feet).
When you have completed this, shut the pump down and continue to rotate while adding weight for two or three minutes. This will burn the core so it will stay in the basket.