Myth's Mk1 40,000 items per hour piston mob grinder for Minecraft 1.9beta5

Uploaded by Mythtri on 10.11.2011

Myth's 40,000 items per hour un-optimised modestly proportioned piston mob grinder
The surrounding area is lit up for 250 blocks in each direction both above and below ground,
giving mobs very little opportunity to spawn outside of the tower. This area is much larger
than needed: Lighting up a 180 block radius should be ample. I should also mention that
anywhere mobs aren't supposed to spawn in this tower is lit up. This isn't always obvious
in the video due to annoying void fog.
The roof looks a bit odd. It's made up from stone half-slabs. The extreme over-hang keeps
the glass sides of the tower in darkness allowing mobs to readily spawn inside, while allowing
a good view of what is going on from outside.
Note: Spiders cannot spawn in this tower. This is intended. Spiders rarely fall, meaning
that over time the tower would otherwise become full of living spiders, with other mobs being
excluded due to the spawn cap being reached.
Here we can see one of the two grinders placed at the base of the tower. Each grinder is
a combination of a gravity grinder and a lava blade. The gravity part speaks for itself:
Mobs fall from above and expire when these meet terra firma. However, it is probably
worth mentioning that the water at the base of each abyss is resting on top of fence posts.
These make the water shallower than if the water was flowing over a block of stone or
The lava blade deals with any mobs that spawn too low to fall victim to the effects of gravity.
A lava blade is just a wedge of lava with the shallowest edge held up by ladders. Water
pushes mobs inexorably towards it. All of the items are then channelled to a collection
point using water streams.
The collection point has a fairly essential garbage disposal lava pit. Without this, the
number of items rapidly builds up causing decreasing frame rates down to single figures
within a few minutes.
You may notice that items are flowing particularly quickly. This is because most of the water
streams are flowing directly over ice blocks (the obvious exception being where the heat
of lava would probably melt it). Likewise, light sources are kept a good distance from
the water streams for the same reason.
This cutaway shows two of the pressure pads present in the tower.
Each pressure pad is connected to its own dedicated piston via 2 red-stone torches.
If a mob spawns on a pressure pad, the piston pushes them down in to the abyss. I've used
wooden pressure pads here so that I can show how it works with a bag item. The ones in
the tower are stone, basically to stop any mob remains unintentionally activating a piston
half way up the tower.
This arrangement is repeated to form a line of 32 pressure pads. A second line is then
created facing the first to form a broken "U" shape with a couple of air blocks between
them. Each pair of lines is then repeated back-to-back to form 4 separate spawn areas,
making up 1 of the 27 floors. This gives a total of 6,912 pressure pads in the finished
Thank you for watching.