how to make a mob crusher
To make a mob crusher, first you make a 2 by 1 doorway. Make sure that you make it two blocks thick. Next, on the back put a block on the bottom and a sticky piston on the top. Make sure that the sticky piston is facing the doorway. Now you have finished the cage part. Next, put a block on the right side. Next put a button on the block and put a redstone torch behind it. Next go three blocks out and put redstone on two of them and five blocks out from that. Next put a sticky piston facing inwards. Next put a block of redstone on the next block. Next put a sticky piston facing the first one with redstone behind it. Next put blocks beside the other blocks till it touches the sticky piston on the back of the cage. Next put a block next to the redstone behind the sticky piston. Next put a redstone comparator facing the block. Next put two hoppers facing into each other. Next put a redstone comparator facing a block. If crushing skeleton put four blocks in a L-shape from the second hopper. Next put a redstone comparator facing a block. Then put a redstone repeater facing into another block. Then check the timing below. The first number is how may blocks you need to put in the hopper. The second number is how many times you click on the repeater. Then, you can start crushing away!
Timing
ONE TALL MOBS:
Guardian: 18+3
Silverfish: 5+0
Endermite: 5+0
Spider: 10+0
Cave Spider: 7+0
Chicken: 2+1
Pig: 6+0
TWO TALL MOBS:
Zombie: 12+1
Zombie Pigman: 12+1
Skeleton: 12+1
Creeper: 12+1
Blaze: 12+1
Villager: 12+1
Snow Golem: 2+1
Cow: 6+1
Sheep: 5+0
THREE TALL MOBS:
Iron Golem: 62+2
Wither Skeletons: 12+1
Enderman: 25+0
Here's a video you can watch. Skip to 3:05 to start building
Timing
ONE TALL MOBS:
Guardian: 18+3
Silverfish: 5+0
Endermite: 5+0
Spider: 10+0
Cave Spider: 7+0
Chicken: 2+1
Pig: 6+0
TWO TALL MOBS:
Zombie: 12+1
Zombie Pigman: 12+1
Skeleton: 12+1
Creeper: 12+1
Blaze: 12+1
Villager: 12+1
Snow Golem: 2+1
Cow: 6+1
Sheep: 5+0
THREE TALL MOBS:
Iron Golem: 62+2
Wither Skeletons: 12+1
Enderman: 25+0
Here's a video you can watch. Skip to 3:05 to start building