Select metal coffee cans with sturdy lids. If the lid is loose or cracked, it will not make a suitable ice cream maker.
Wash the coffee cans and lids with soap and water. Rinse and dry.
Combine 2 cups of evaporated milk, 1/2 cup of sugar and 1/2 tsp. of vanilla in the 1-lb. coffee can, or use your own recipe or add a little fruit or nuts to the recipe.
Place a lid snugly on the 1-lb. coffee can.
Set the 1-lb. coffee can in the center of the 3-lb. coffee can.
Pack the larger can with crushed ice, surrounding the smaller can with the ice.
Cover the top of the ice evenly with 3/4 cup of rock salt or ice cream salt.
Place a lid snugly on the 3-lb. coffee can.
Roll the can from one person to another, such as across a table or on a flat concrete surface, for 10 minutes. Allow the youngsters to do this, instead of hand cranking. Don't turn the game into kick the can, which can knock off the lids, thus spilling the ice cream mixture and salt.
Open the can and carefully remove the smaller can. Be careful not to get salt into the smaller container.
Stir the ice cream mixture thoroughly. Replace the lid, and repack the smaller can into the larger can, adding crushed ice and more salt.
Place the lid on the larger can and roll for five more minutes to finish the ice cream.