This is a compact arrangement of the item thieves, and the machinery which makes it all work.
Guide to Item Thieves
The best tip for making an organized base, is to make a subfloor, or a basement. Just like real buildings, where pipes and wires are hidden in basements and walls, this same principal can make your base neater looking. I've created a platform 6m in the air to demonstrate the concept. If I were actually building this in a game, these thieves would be 1m apart. But for clarity in screenshot purposes, I spaced them 3m apart and painted black lines so you can see how far everything is spaced. Once everything related to these machines is built, you should never need to visit this basement area again, so it's alright if you want to make it compact as possible.
I've labeled the first two thieves to be worked on, the Garbage Thief and the Organic Thief, and how to power them.
When you stand on these thieves, they will draw a lot of power. Coal is the appropriate power source because the generators will store 1000 power in them. You would need 5 MK1 Power Storage Blocks to equal that capacity. There just isn't enough room down here to place all those blocks.
Coal will come up a belt and hit the turntable. The reason to use turntables, and not a hopper, is to ensure coal will distribute to the other thieves a little faster. So, why use a priority spliter to fill up the Organic Thief with coal first? No good reason. It looks a little better in a screenshot. A turntable is cheaper.
Next, I've placed 8 Minihoppers on the bottom of the thief. That's not a lot of storage, however, there shouldn't be that many bug parts lying around in the first place. To keep the build costs low, always use logi/mini hoppers, just to get something working. Then you can upgrade later. Don't use the high build cost of Storage Hoppers as an excuse not to automate. There's no good excuse not to at least get the thing working.
Place belts so that everything merges into one conveyor and meets at a turntable 1m off the floor.
The turntable will feed into 4 macerators. Again, if you don't have enough to build 4 macerators, make at least one and get the system working.
Macerators only work if they can output their contents to a hopper. We can use that diagonal trick again to get the contents out of a hopper, and diagonally input the ground up ore back into the macerator for complete destruction. Alternatively, the ore can be sent on to a smelting system. But for the purpose of this guide, I'm demonstrating a compact macerating layout which fits in the 3x3 footprint of the thief.
The Garbage Thief layout is similar to the Organic thief. The difference here being I'd use Storage Hoppers if I could, because you probably have a lot of junk that has been dug up so far. Again, minihoppers are better than no thief at all. The belts here flow into a hopper set to Remove Only Because we're going to attach paste builders on the 5 remaining faces.
It should look like this. Notice that this minihopper that we attached all the paste builders to has 2m of belt to drop it down low enough so when we attach Storage Hoppers here, they're not touching the conveyor belts, which would make paste loop back into the minihopper and jam up the system.
All that remains to do here, is attach the H.E.I.S.T. units to your hoppers and paste will be given to you each time you stand on the thief. As you can see, this only holds a few hundred paste. This system is only meant to clear your inventory of junk. If you need thousands of paste, your best option is to mine veins of coal and turn that into paste.
This is what we have so far:
We can take what we've learned up to this point, and duplicating the hopper setups from the previous two thieves. On the left side of the screenshot is the Bar Keeper. For this guide, there isn't much to really show on this thief. The bars can be conveyed anywhere you need them to go. Into a mass storage, back through a production line, etc... All I can really do in this guide is dead-end the line right here. Moving on...
Storage Hoppers would be a good choice for the Ore Thief. Again, duplicating the layout from the previous thieves, the belts need to merge into one hopper with a Remove Only permission.
Again, coal is going to be the power source for the mini-smelting operation. We can use 2 generators to power 4 smelters by siphoning off the coal used to power the thief.
While it will probably be the case the basic smelters will be used, for this guide I built it with standard ore smelters as a demonstration of how to build it with future expansion in mind, in case you wish to add induction coils to the smelters. Although, most likely, you won't even have ore in your inventory anymore by the time you get to standard smelting.
The final step, is hooking up the output of the smelters, to the same line as the Bar Keeper, and you're done. What we should end up with, is nice and neat on the surface as we run over the thieves.