Preheat oven to 350 degrees. In a mixer with a paddle attachment, cream butter then add the sugar and vanilla and continue creaming till well combined. In a separate bowl stir together the flour, cream of tartar, baking soda and salt then add to the mixer and mix on low. Then add the cornflakes, pecans and coconut and gently mix to combine. Roll into 1 ¼ inch balls and place on an ungreased cookie sheets spacing them 2 inches apart. Bake for 10 to 12 minutes, or until very lightly browned. Cool 2 minutes before removing from the cookie sheet.