Do you have a castle in Minecraft? Do you want to build a drawbridge? Here's how, now we'll teach you!
Steps
Step 1. First of all, in front of your castle / tower of power or similar structure, drill a hole 4 blocks long, 6 wide and 4 deep
Step 2. Then create 6 sticky pistons
Place them 2 blocks away from the end in width. Also make sure they are 1 block away from the end in length.
Step 3. Now, place the blocks on top of the pistons
Then we will have to connect some redstone circuits to the pistons (but not to those in the center). Then, connect the 2 circuits together. Take a redstone repeater and place it where the 2 circuits connect.
Step 4. Now comes the tricky part
Take 2 redstone repeaters and place them 1 block away from where the central pistons are.
Step 5. Build the shape of a ladder and place a lever on top
Connect the redstone dust to the lever.
Step 6. Now, test the mechanism
If it works, cover it completely and get ready for the next step. If that doesn't work, try repeating the steps above or try to figure out why.
Step 7. Make or find some buckets (you can make them by putting 3 iron ingots in the shape of a bucket / bowl) and fill them with water or lava / magma
Step 8. Now, if it works, activate the bridge
If you covered the hole, then next to the bridge make 2 holes of 3x1 blocks and cover the base. This way you will get the shape of a pasture, if you have done everything correctly.
Step 9. Fill the two openings with buckets of lava / water
Fill the bucket and pour the contents from the opposite side. Continue bucket-filling the openings until they are full (but not overflowing!).
Step 10. You now have a nice drawbridge
Make sure it works, and if you don't understand the instructions, watch "Paul Soraes Jr's Survive and Thrive season 2" on YouTube.