| Make your own cotton gin model
Things You Will Need:
2 thin plastic combs
Metal paper clips
Find a rectangular box, like those used for kitchen matches. Cut about 1/2 inch off the top of each the two long sides so the short sides of the box are taller than the long sides. This is the base of the cotton gin.
Set aside cut pieces from the sides of the base.
Cut a piece of cardboard to fit as a lid on your cotton gin model. Cut it longer than needed and fold a 1/2-inch flap on one end. Glue this flap to one of the short sides of your cotton gin model, allowing the cover to open like a hinge at the fold.
Measure the diameter of a thread spool.
Using a ruler to measure the long side of the cotton gin base, mark a spot about the same distance from the end as the diameter of the spool. Do the same on the other long side.
Make a notch at the marks using scissors.
Straighten a paperclip and thread through the hole in the middle of the spool.
Nestle the paperclip into the notches on the base, holding the spool in place in the center of the model. Leave one end of the paperclip longer to twist into a handle.
Cut the teeth of a plastic comb until they are about 1 centimeter long. Cut the length of the comb to fit widthwise inside the cover. Position the comb with teeth facing the front of the gin, angled slightly down, right over the spool. Glue in place.
Cut the teeth of a plastic comb until they are about 1 centimeter long. Cut the length of comb to fit widthwise inside the base. Glue this comb piece to the base next to the spool, teeth facing the back of the gin. The comb should be about halfway between the bottom of the base and the top. This is where the cotton would be caught after going through the first set of teeth.
Cut a piece of cardboard to glue across the top of the base over the second comb as a brace.
Add a third piece of comb about a centimeter behind the second, also halfway between the bottom of the base and the top, teeth facing the back of the gin. This is the final push for the cotton.
Cut a piece of cardboard for the back of the gin long enough to reach from the end of the last comb to the top of the back end. It will be at a 45 degree angle. Glue in place.