Instructables “21 Projects Guaranteed to Keep Your Kids Occupied This Weekend” is a free Kindle book, that I picked up to have a read of; there are some cool projects in it that would be worth a look at doing with the Cub Scouts
21 Projects Guaranteed to Keep Your Kids Busy This Weekend give you full step-by-step instructions for 21 amazing kids activities that your family will love. Learn how to entertain your kids with the DoodleBot360, LED Throwies, Grow Your Own Magic Crystal Tree, the Marshmallow Shooter and other projects that are sure to hold your child’s attention for hours! All projects come from Instructables.com, are written by kid-fun experts, and contain pictures for each step so your children can easily do it themselves. Have fun!