What does it take to build a an auto Wither Farm?

[MikW]

I'm currently moving on to the more advanced stuff... I need a lot of nether stars for Draconic Evolution. So what does it take to build a Wither Farm? I know it needs some kind of auto placer, a wither skeleton farm, and some kind of mob grinder. The mob grinder part shouldn't be hard... the Draconic Evolution mob grinder is made for that purpose.

Any advice on the other things though? I have a ton of resources available, so don't worry about the cost.

Also, I'm on the DW20 1.10.2 pack.

P.S. Don't suggest mystical agriculture for the wither skulls, it's not in the pack.

 

[Cptqrk]

If you followed DW20's let's plays for that pack, he makes a fairly simple, yet power hungry wither spawner/killer system.

Look at the season 8 episode 45 and 46 for his setup.

 

[Cpt_gloval]

Well an octadic ender io spawner with with skeletons feed to a tinkers large sword with as much beheading as you can get will get you the needed skulls.
Lots of soul sand.
Mechanical users from extra utilities to put the stuff in world.
Ender io blast proof block setup in 2 flat 7x7 plains 2 blocks apart with the users build into the bottom one with a timer to tick the user's into action about every 30 seconds, 200 ticks.
Setup the system to build the wither laying down on the bottom plain.
The wither will form stood up and stuck in the upper plain of blast proof blocks.
Draconic grinder to kill him off once fully spawned.
Some form of vacuum hopper to pickup the goodies.

In my dw20 pack I set this up about 50 blocks above my base with ender chests to feed and return materials.
Stack and sand and 48bskulls in, 16 stars out a fresh minutes later.

 

[Nuclear_Creeper0]

Draconic Grinder, with like 8 spawners 1000s of stars per hour. You need the draconic portal to teleport them into a little box.