How to build a Minecraft Mob Grinder

related article:
online voxel sphere generator
for Minecraft
A Minecraft mob grinder will gather, trap and kill mobs collecting their drops such as arrows, sulphur and string. This guide will show you step by step, complete with screenshots and interactive floor plan, how to build one.
Update: check out my Minecraft Piston Mob Grinder
How the mob grinder works
The mob grinder is a tower with floors where there is no light so Minecraft mobs such as spiders, zombies, and skeletons will spawn, even in day time. The mobs walk around and drop through holes in the floors. On reaching the first floor, water traps channel them through holes to their fate, a water ride into lava where they die and their drops are collected.
How to build the mob grinder
1. Start by building a base, 23 x 23 blocks. The base dimensions come from the first floor which will be made of:
- 1 block for the outer wall
- 2 blocks for the drop hole through which mobs fall
- 8 blocks for the flowing water which carries mobs to the drop hole
- 1 block spacer (to separate the next flowing water)
- 8 blocks for the flowing water which carries mobs to the drop hole
- 2 blocks for the drop hole through which mobs fall
- 1 block for the outer wall
2. Build a water channel. Mobs fall from the first floor through a 2 x 2 hole in each corner. They fall to the ground floor where a 2 wide by 8 long water channel pushes them to their doom. Water flows over 8 blocks and then stops, but items will carry on and fall if there's a drop at the 9th block. Collect and place water using buckets made from iron. Here's 1 of my water channels:
3. Build a lava trap. The mobs are killed using lava. To prevent the stuff they drop being incinerated you use a 'feature' of the game where lava will flow over an empty block if a ladder is placed on an adjoining block. In the screen shot below, see how the lava juts out over the 'empty' block allowing items from the mobs that die to fall. Collect and place lava using buckets made from iron.
4. Make a water collector. Add another water channel to collect fallen items from the mobs that die like below.
5. Now you'll need to repeat steps 2-4 to build the water channel and lava trap for each corner. Join the wall up around the side and you have built the ground floor of your mob grinder tower. The hardest bit is over.
6. Build the collecting floor. This floor extends beyond the grinder to allow 4 water channels around each of the 4 corners of the floor below. Mobs on this floor will wander around and eventually end up in the water which will channel them to the corners and down to the ground floor. Note this floor is 2 blocks deep to allow a solid block for the water flow to sit on.
7. Build as many other floors as you like. The floors above the 1st floor do not need water channels. They just need to have holes in the floor through which mobs can drop. Mobs will happily drop down holes with a drop of 2 or 3 blocks. DO NOT have any overlapping holes from one floor to another otherwise the mobs will not drop. I've found a checkerboard pattern of 4x4 solid then 4x4 holes very successful giving plenty of space for mobs to spawn as well as a good chance for them to drop to the floor below. If doing this, alternate the solid and holes on each floor so that mobs only have to drop 2 blocks to the floor below. These floors should have 2 blocks high space for mobs to spawn and walk around in. The roof of your top floor must be completely sealed so all floors are dark and mobs can spawn there, even in day time.
The completed mob grinder in action! A spider burns to death on the lava. Items dropped by other mobs that have died have been carried by the water channels to the middle.
Some final notes:
- Mobs will only spawn more than 24 blocks away from you OR 24 blocks away from your spawn point. Don't stand too close to your tower otherwise mobs won't spawn there. Don't build too close to your spawn point either.
- More floors means more chances for mobs to spawn so add as many floors as you like.
- I built my mob grinder out to sea hoping that mobs would be more likely to spawn in my tower than outside it as there is no land for them to spawn on. I don't know if this is true.
- Put torches on your ground floor to stop mobs spawning there. Add a door for easy access.
- A ladder up the side of your tower with filled in holes on each floor will provide easy access for maintenance or building more floors.
Have fun!
Related articles
Comments(112)
i have a big problem and no solution yet: parts of my tower are not dark, preventing monsters to spawn. theres no torch or lightsource nearby. i looks like the tower has a hole in the ceiling or something although everything is closed, any suggestions? sry for my bad english :D
I am having the same problem as this person, I built it in survival on pc, no torches or holes inside as well but it is still so bright inside. Tried adding a second layer of stone on top but it still comes through like this. anybody else have this problem or any solutions to it?
http://i.imgur.com/kwvklf2.jpg
as you can see, its all as it should be except for the light. I'm not getting many mobs from this which is really annoying, spent 5 hours on this to grind some gunpowder but hardly any so far =/
The solution? I got rid of the lava and opened up holes for the mobs to plummet to their death. For grins I built a second mob grinder from a 30 square high pedestal and the loot is rolling in. Fun to see them all fall too
Secondly, on the xbox version, would this still work if the floors had a 3 block gap between each other so as to spawn Endermen? Would the other mobs drop drop the same or is 2 the limit?
And last of all, anyone wanting to turn their grinder into an EXP grinder (aswell as its default item grinder), just add some sticky pistons above the last lava block (not the blade that sticks out), add some wiring and a lever and you've got an EXP and item grinder with minimum work! Stick one of these on each and you can have three of the grinders getting you items whilst you sit there and mash some creepers for EXP or if you have friends you can each pick a grinder and wail away on the bad guys!
More things like this please. Good work.
And for Edge yes making one wall glass would count as sunlight
It works tho
Now for those slime traps.
It seems to speed things up over the original design a little bit.
It took me two attempts to build this on Xbox 360 edition. The first attempt went horribly wrong because the channel system was off because i didn't remember to make the next floor 40x40. The second time was perfect. Amazing drops per hour and lots of fun to watch. Thanks for the tutorial!
Trollz
Just made a tower with water to kick out the mobs and they will die for fall damage. Example:
l=dirt\cobblestone O=Mob
O
llllllllll
l O
l O
l O
l O
:D
took all my study time tho :(
Thanks,
Ubersmartypants
but any idea of where or howfar i should put the item pickup, so spiders wont follow you and other mobs still move.
the guide i was using before didn't say anything about the mobs on the Level before the grind.
So they kind of just wander around, and eventually kill themselves.
Might need to think and try and reconfigure if possible for the water channels on the bottom level. Though i've got ten levels up this is going to be a puzzle.
I only have one harvester and collector. But it seems to work fine.
Unfortunately, in 1.8 this is a nightmare : Endermen have enough space to spawn (since above the spwaning platforms there are actually 5 blocks of air) and cannot fall (since max. 2 height to "drop" to platform below). Moreover, they pickup blocks from everywhere including below their feet, and place them elsewhere randomly, breaking the whole structure.
Too bad :(
It does still work in 1.8.1, but Endermen will remove your blocks from the inside. You will need to repair every so often to stop the light getting in. I don't know if they can take up the floors or canal sides, but water will kill them so there is that.
May have to refine it for later versions, Kev. But many thanks!
If you don't want to repair the ground floor all the time, re-work your water canals so that they are located in spots where there are 2+ vertical blocks :)
Word of advise: make sure the water channels on the second floor are all 8 blocks long so the water goes right to the edge but doesn't spill through the hole or you'll have a bunch of mobs hangin in the jacuzi and not falling through.
Tried the signs instead of ladders but still getting very little string. Going to try to incorporate cacti in there somehow...
just stand in middle of spawner to kill spiders since the can see through blocks (use their x-ray vision against them :D
goo.gl/rl5Oq
After that, I dug a central hole to channel all the flows into, and led it through a small tunnel underneath the floor of one of the main holes, seemed to help a lot, the spiders don't clog up anymore
Got back to find minecraft seriously lagging, and when sound was switched back on, sounded like there was around hundreds of spiders loitering and blocking the entire system up.
Soon as you go near any of the corners, they just start jumping down in swathes.. but if you stay in the middle, they must just all stick above your head, which I suspect also starts to affect other mobs spawning.
Going to try experiment with a central trap of some kind to hopefully stop the spider infestation so they don't keep blocking off the other mobs
I definitely get way less string, the only way to really kill spiders and guarantee string is a drowning trap which is slow. I'd say if you really need string, find a spider mob spawner in a dungeon and setup a trap there. I got lucky and found one spider spawner only 5 blocks above a 2nd spider spawner, i get tons of string now :)
"I've built it like you said, but I had one question. When the spiders die, they end up jumping up into the lava so that the strings they drop burn as well, is there a way to avoid that?"
I'd like to resolve that problem too if possible, string is kind of important to me :P
right now i'm working on a peaceful mob grinder, the goal is pork. spawn rates for peacefuls are low though, so it's frustrating. right now it's just set as a falling trap, a 23x23 spawn floor with water sucking to a fall. i wait in a pit dug below, out of the 24 block exclusion zone. the whole thing is surrounded by water and land with grass stripped away. if i add floors, how many blocks of air in between?
For "6 collecting floor 1" I made that layer as you suggested, however I was having MOBs jumping out of the collecting streams and basically just hanging out in the tower.
So i made a 2nd layer of "6 collecting floor 1" except without the water, this way when mobs fall in the collecting stream they have no way out.
I'm still having some problems with spiders, the majority of them can still avoid the collecting holes, once i get near the hole 3 or 4 of them will suddenly jump down, then i simply walk them to the lava.
Other than that this has finally made me capable of stocking up on gunpowder to finally make some TNT, woot. Got a basic 5 level version running, done all with stone i mined myself woot.
thanks for the posting, your interactive schematic thing helped tons!