Hi beginning of this year March to be precise I put up a mob farm which has been downloaded over 100 times. Recently I thought I might update it here is the result. There are various features that I thought those of you that were interested might appreciate. There are too many features that I have adapted from others to give them all due credit. Suffice it to say none of the Redstone mechanisms in this are in fact my own but are adaptions. In the collection part I have added witches and found they are very difficult to kill. Tried squashing them with pistons immersing them in lava but these did not reliably work so only choice is the big drop. This created collection complications so there is an item elevator that will automatically transport items about 33 blocks upwards into the sorters. You may be wondering why I persisted with the lava for other mobs the catch is the behaviour of slimes a large slime will drop 30 blocks but just plagues up the works because it breaks into four of slimes not into slime balls. Once the lewd gets into the sorters obviously it is separated into various categories. These are then transported with chest carts to the final storage. The design has three large chests per item. Depending on your rail system you could transfer your loot a long way from the farm. Final note there is a peculiar mechanism at the bottom of the upper collection hoppers. This is there because of baby zombies they go through the system get trapped in that area and clog the works up I have put a water stream which moves them into a lava pit. PS Position spawn height at level 55 and make sure biome is swapland.