The Automatic TNT Miner will throw a massive amount of TNT on the ground. It is used for mining and destroying the area completely.
This guide will let you know to make an Automatic TNT Miner.
Place a dispenser on the right side of quartz blocks and add two more smooth quartz blocks on the left side. Then you have to remove the first two quartz blocks as shown in the image below.
Place one smooth quartz block at the bottom and add a redstone repeater at the top of it. Add one more redstone repeater on the upper redstone and set both the repeaters to maximum delay.
Add more smooth quartz blocks at the bottom and use redstone dust to connect the redstone repeaters.
Place five more smooth quartz blocks on the right side and add redstone repeater at the top of them. After this, add four smooth quartz blocks on the left side of these repeaters and use redstone dust on them.
Place dispensers alongside these redstone repeaters and fill all the dispensers with TNT. Add some smooth quartz blocks on the left side as shown in the image below.
The next thing you need to do is to make a redstone clock on these quartz blocks. Set the repeaters of cloak to 3 tick delay.
Add more slime blocks just next to the previous one and place a lever at the right bottom part.
You have successfully made an Automatic TNT Miner, it is the time to check that out.