Boom! Canon in Minecraft

Welcome to my first one! Here is how to make a safe-ish boom cannon that will send you flying!!

Make a 7x9 out of obsidian or Gold

Add TNT along the inside of the 7x9 then add a three block stair case on one of the longer sides

Put redstone on top of the 7x9 all the way around put some on the stairs as shown in the picture.

add two fences in the middle then put a bottom on the side of the top brick on the stairs.

Stand on the fence and press the bottom BOOOOM!!