Set down a piece of wood that is 4 inches by 4 inches by 2 feet so that a 2-foot side is facing up. Use the measuring tape to mark two points for two holes -- one above the other -- which the PVP pipes will fit into. Flip the wood over and mark the same spots on this second side.
Drill two holes with the hole saw through the block of wood, one hole at each mark. The holes should be as wide as the pipes are. Vacuum up any sawdust.
Assist the child in sliding a pipe through one of the holes, until there is enough pipe through the other side to use as a handle for turning. Repeat with the second pipe.
Assist the child with sliding the empty wrapping paper tube onto one of the pipes. Crumple up pieces of newspaper and stuff them inside the empty wrapping paper tube to brace the wrapping paper tube so that it turns with the pipe. Repeat with the full wrapping paper tube on the other pipe.
Unroll enough paper from the full wrapping paper tube until the end of the paper touches the empty spool. Tape the end onto the empty spool with the packing tape.
Begin to turn the pipes so that the paper begins to wind around the empty spool. Experiment with different speeds for each pipe to see which should be faster, if any.