Hello all. I'm very new to this. Last year I done a little welding course. And iv finally got around to buying a entry level welder. Wolf 140 mig weld gas no gas welder. All was going well until I changed rolls. I got the wire in. Fed the wire through tightened everything up. Not to tight. But the wire just doesn't feed. You can here the motor going. But the wheel just doesn't move. If I loosen it off it works but obviously it's to loose to feed the wire. Can anybody tell me what I'm doing wrong.