This is a server, that has a plugin that lets them pick up spawners (such a feature is usually reserved for a donation rank, which is technically against Mojang's TOS). He's not asking how to build a grinder according to where existing spawners are placed, he's asking how to place spawners so that he gets the least amount of loss (the most skeletons in the least amount of time).
Cages are only active around the player in a 33x33x33 cube centered on the player, or up to 16 blocks away in all 6 directions. Assuming that a cage is placed in all 8 corners and that every single cage is placed with 8 blocks of space between its neighbors, this means we can have a 5x5x5 cube of cages with zero spawning or detection box overlap, minus 3 cages to give us space for infrastructure (access to the AFK chamber, space for the water elevators to move skeletons onto our sword, space to run redstone, and space for item storage). That's a grand total of 125 cages, with the only loss impact occurring from skeletons falling through lower cages' detection boxes (don't think there's a way to avoid that aside from just sticking with 25 cages on a single layer).
quote=joeychin01
I am in a survival server with silkspawners, and have 42 skeleton spawners. What is the most effective XP grinder I can make?
I've not personally played with SilkSpawners (or its non-bukkit equivalent) but it is my understanding that this mod doesn't effect anything other than allow spawners to be obtained with a Silk Touch pick.
The following is my analysis based on the known rules for behavior, not practical experience.
The main design constraint on mob spawners is getting the mobs out of the spawner detection area [a 9×9×9 area, centered on the spawner block] as quickly as possible.
[Note that mobs from spawners do count toward the mob cap (mobs will not spawn other than from spawners), but spawners are not limited by the the mob cap (mobs will continue to spawn from spawners).]
Placing an array of spawners so that the 9x9 horizontal areas touch (but do not overlap) guarantees no interference between spawners. [This may need to be expanded to 10x10 or 11x11 for spiders.]
Assuming your position is on the block 10 below the central spawner (10 = 4 blocks spawner detection range + 2 blocks for mob trans port {2 because mobs can bob in water} + 1 floor + 2 player space + 1 player floor), the maximum range on the cardinal directions [N,S,E,W] at spawner level at which other spawners can detect the player is 12.49 [ SQRT(16^2-10^2) = SQRT(256-100) = SQRT (156) ].
The central area spawner level would look like this (with more air extending a further four blocks at each edge):
SAAAAAAAASAAAAAAAAS
AAAAAAAAAAAAAAAAAAA
AAAAAAAAAAAAAAAAAAA
AAAAAAAAAAAAAAAAAAA
AAAAAAAAAAAAAAAAAAA
SAAAAAAAASAAAAAAAAS
AAAAAAAAAAAAAAAAAAA
AAAAAAAAAAAAAAAAAAA
AAAAAAAAAAAAAAAAAAA
AAAAAAAAAAAAAAAAAAA
SAAAAAAAASAAAAAAAAS
with the red spawners out of range [ 9^2 + 9^2 + 10^2 = 81 + 81 + 100 = 262 > 256 ]
If one assumes the standard glass pillars atop each spawner, one could move each of the corner spawners diagonally closer by one bklock bringing them in range, but causing a degree of overlap in the spawn areas.
The wiki states "mobs [are] more likely to spawn closer to the spawner than farther away [from spawners] ", so the increase from adding another four spawners would probably exceed any loss from spawner-spawner interaction.
I suspect that pushing this idea further would eventually result in the lost spawning spaces (due to the glass pillars needed to prevent mobs from getting stuck atop the spawners) costing more spawns than the marginal spawners add.
The spawner entry notes:
If the block fails to spawn any mobs because it did not pick any suitable locations, it will repeat this process every tick until it succeeds. Only when it manages to spawn at least one mob will it start waiting for the next cycle.
Combined with the ambiguity of the "mobs [are] more likely to spawn closer to the spawner than farther away [from spawners] ", both quite complex and dependant on the geometry of the air/spawner matrix.
If you wish to do a more thorough analysis extending to using all 42 spawners in one instalation, I would suggest designing your kill station first.
Note that the above does not account for such possibilities as using tamed wolves as the kill mechanism (possibly using slime blocks & pistons to move teh XP to the player as seen in some pigmen XP farm designs).
EDIT:
I've just realized that you can incorporate more spawners by moving the kill site to the top of the central spawner (standing on the 3rd block above it) and transporting the spawned mobs around the mob detection range of the spawner array.
The same principles will apply, but the maximum range on the cardinal directions [N,S,E,W] at spawner level at which other spawners can detect the player increases to 15.71 [ SQRT(256-9) ]
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"Why does everything have to be so stoopid?" Harvey Pekar (from American Splendor)
WARNING: I have an extemely "grindy" playstyle; YMMV — if this doesn't seem fun to you, mine what you can from it & bin the rest.
I am in a survival server with silkspawners, and have 42 skeleton spawners. What is the most effective XP grinder I can make?
Are all of the spawners in the same place? It would really depend on the arrangement of the spawners.
Check out my suggestions! Here is one of them:
This is a server, that has a plugin that lets them pick up spawners (such a feature is usually reserved for a donation rank, which is technically against Mojang's TOS). He's not asking how to build a grinder according to where existing spawners are placed, he's asking how to place spawners so that he gets the least amount of loss (the most skeletons in the least amount of time).
Cages are only active around the player in a 33x33x33 cube centered on the player, or up to 16 blocks away in all 6 directions. Assuming that a cage is placed in all 8 corners and that every single cage is placed with 8 blocks of space between its neighbors, this means we can have a 5x5x5 cube of cages with zero spawning or detection box overlap, minus 3 cages to give us space for infrastructure (access to the AFK chamber, space for the water elevators to move skeletons onto our sword, space to run redstone, and space for item storage). That's a grand total of 125 cages, with the only loss impact occurring from skeletons falling through lower cages' detection boxes (don't think there's a way to avoid that aside from just sticking with 25 cages on a single layer).
quote=joeychin01
I am in a survival server with silkspawners, and have 42 skeleton spawners. What is the most effective XP grinder I can make?
I've not personally played with SilkSpawners (or its non-bukkit equivalent) but it is my understanding that this mod doesn't effect anything other than allow spawners to be obtained with a Silk Touch pick.
The main design constraint on mob spawners is getting the mobs out of the spawner detection area [a 9×9×9 area, centered on the spawner block] as quickly as possible.
[Note that mobs from spawners do count toward the mob cap (mobs will not spawn other than from spawners), but spawners are not limited by the the mob cap (mobs will continue to spawn from spawners).]
Placing an array of spawners so that the 9x9 horizontal areas touch (but do not overlap) guarantees no interference between spawners. [This may need to be expanded to 10x10 or 11x11 for spiders.]
Assuming your position is on the block 10 below the central spawner (10 = 4 blocks spawner detection range + 2 blocks for mob trans port {2 because mobs can bob in water} + 1 floor + 2 player space + 1 player floor), the maximum range on the cardinal directions [N,S,E,W] at spawner level at which other spawners can detect the player is 12.49 [ SQRT(16^2-10^2) = SQRT(256-100) = SQRT (156) ].
The central area spawner level would look like this (with more air extending a further four blocks at each edge):
with the red spawners out of range [ 9^2 + 9^2 + 10^2 = 81 + 81 + 100 = 262 > 256 ]
If one assumes the standard glass pillars atop each spawner, one could move each of the corner spawners diagonally closer by one bklock bringing them in range, but causing a degree of overlap in the spawn areas.
The wiki states "mobs [are] more likely to spawn closer to the spawner than farther away [from spawners] ", so the increase from adding another four spawners would probably exceed any loss from spawner-spawner interaction.
I suspect that pushing this idea further would eventually result in the lost spawning spaces (due to the glass pillars needed to prevent mobs from getting stuck atop the spawners) costing more spawns than the marginal spawners add.
The spawner entry notes:
If the block fails to spawn any mobs because it did not pick any suitable locations, it will repeat this process every tick until it succeeds. Only when it manages to spawn at least one mob will it start waiting for the next cycle.
Combined with the ambiguity of the "mobs [are] more likely to spawn closer to the spawner than farther away [from spawners] ", both quite complex and dependant on the geometry of the air/spawner matrix.
If you wish to do a more thorough analysis extending to using all 42 spawners in one instalation, I would suggest designing your kill station first.
Note that the above does not account for such possibilities as using tamed wolves as the kill mechanism (possibly using slime blocks & pistons to move teh XP to the player as seen in some pigmen XP farm designs).
EDIT:
I've just realized that you can incorporate more spawners by moving the kill site to the top of the central spawner (standing on the 3rd block above it) and transporting the spawned mobs around the mob detection range of the spawner array.
The same principles will apply, but the maximum range on the cardinal directions [N,S,E,W] at spawner level at which other spawners can detect the player increases to 15.71 [ SQRT(256-9) ]