Ideally, the media should enter the printer from directly behind the printer through the fanfold media slot in the rear of the printer. See Printing on Fanfold Media.
Lower the print speed to decrease the chance of motor stalls. The roll typically has the highest inertia when trying to start the roll moving. Larger media roll diameters require the printer to have more torque applied to get the roll moving.
The media should move smoothly and freely. It should not slip, skip, jerk, bind and then move, etc. when mounted on your media stand.
The printer should not touch the media roll.
The printer should not slip or lift up off the operating surface.