Hello every one! I have been offline for a while, and hadn't been able to make instructables since. But I'm back now, and will show you how to make the infamous minecraft tnt cannon! you don't really need too many recources to make this, but thanks to the 0.8.0 update, I can demonstrate in creative. Now, let's get started!
Step 1: materials
obsidian, flint and steel, tnt blocks, a slab, and a bucket of water.