gilotine door?

yes i built a 4 x 4x8 coal bin , i made it out of all 3/4 plywood with a 2x2trap door , but i would like to put a gilotine door in the bottom of it so i dont have to climp up and in it to shovel out coal , , what would be the best way of making one of these? the whole box is sheeted and complete, i was wondering how high from the ground to make it, and a safe one ,soo the coal dont come flying out and cant close the door , the roof lifts up and is sheeted with roofing tin

Hello first-timer well if your front corners uprights are shaped like a L all you will have to do is get two 1x3 4ft screw them on the side inside make a 1 inch channel then if you have a piece of 4x4 playwood cut it in half so you have two 2ft pieces then just slide one in from the top to the bottom then the second one in when the coal gets low take one out that is how I made mine 12 to 15 years ago still using it have fun good luck