I constructed a Wither Skeleton Skull Farm in XYZ 400,54,2675. It uses 6 Flying machines on 3 platforms to push mobs into a grinding area down below (24+ blocks). I have also put buttons in an exterior area to avoid spawning outside the fortress zone. I know mob rates are low in the server but, I hardly get mobs to appear. And, even more, when killing them manually without the flying machines running it seems to be more productive. I do not know if anything is not working properly...
Can anybody point my errors? Thank you!