So you’re playing Rotarycraft, you’ve got the blast furnace, the worktable, a fermenter or two, and grinder. What do you do next? Farming? Heck, no. You go directly for the machine that will help you tear apart the earth’s core in search of filthy lucre and non-sustainable natural resources: the boring machine.
The Boring Machine
Contrary to a misreading of its name, the boring machine is really quite interesting. Power requirements are not static but dependent on what the boring machine is trying to dig through. To give you some idea of what is minimally needed, though, in order to dig a 5×7 tunnel through smooth stone, a gasoline engine can’t manage by itself. If you use a steel 8:1 gearbox in torque mode, it will work. You need steel because a stone 8:1 gearbox will explode, since this exceeds the torque limit for stone shafts. This information is in the Rotarycraft in-game manual.
Let me take a moment to commend Reika on his in-game documentation. More and more, modders of large mods are putting some kind of in-game user manual into their mods, and I welcome this. Not only does it provide an easy, centralized location for me to learn about the mod (rather than scouring the Internet for scattered and often out-of-date information on incomplete wikis, forums, Reddit, and YouTube), but, for me, it contributes to game immersion. In real life I learn from books, and now I can in Minecraft, too. The problem with some mods’ in-game documentation, as well-intentioned as it is, is that it can often be difficult to use or browse, or else it is incomplete at a really critical point. Rotarycraft’s in-game manual is unusually polished and easy to navigate. If I were to find one fault with it, it’s that it isn’t searchable (or it has no index, if realism is desired). This means that I either have to remember what category Reika put a particular machine in, or I have to skim through the manual to find the machine. I could say the same thing, though, of virtually every in-game manual I’ve encountered. The only in-game manual I have encountered that is significantly easier to use is Thaumcraft’s Thaumanomicon, which has no pretension of working like a book.
So, returning from that tangent, in theory, you can make the boring machine work with a gasoline engine. For our purposes here, however, I would suggest you go ahead and get into AC electric engines. An AC electric engine produces twice the power of a gasoline engine (appr. 131 kW) at four times the torque (512 Nm). I, personally, have had great success merging the energy of two AC electric engines (for a total of 1024 Nm of torque) and sending it through a worm gear. A worm gear multiplies torque by 16, like a 16:1 gearbox set in torque mode, but with a little loss to rotation speed. The advantage? No need for lubricant. This increase in torque is especially helpful as you bore nearer to bedrock, where you’re more likely to encounter obsidian. Obsidian blocks take, I think, 512 Nm of torque each. This means that if you are using two AC electric engines and your boring machine tries to take on two pieces of obsidian at the same time, all you’re going to get from your boring machine is sound and fury, signifying nothing. However, by first sending the energy through a worm gear, your boring machine should be able to handle essentially anything except a solid wall of obsidian (which would be pretty rare). It’s not terribly fast, but when digging a 5×7 tunnel (that’s 35 blocks at a time), it’s fast enough.
The AC Electric Engine and Magnetizing Unit
Okay, so let’s figure out the AC electric engine. To work, it requires two things: 1) a magnetized shaft core and 2) a rapidly alternating redstone signal. The magnetized shaft core loses its magnetic charge over time, so this item work’s kind of like a rechargeable battery. To magnetize or re-magnetize a shaft core, you have to place one inside a magnetizing unit. The easiest way to power a magnetizing unit at this point is to use a gasoline engine and a 4:1 gearbox (stone will work just fine) set to speed mode (so you’ll need some of that lubricant you’ve been making). A half stack of ethanol crystals will charge the shaft core to 120 microTeslas, which lasts a lot longer in an AC electric engine than the 32 minutes the half stack of ethanol crystals ran the gasoline engine.
However, before you put those ethanol crystals into the gasoline engine you need to set up the alternating redstone current (AC means “alternating current” for the electrically challenged), because the magnetizing unit needs it just like the AC electric engine does. All this alternating redstone current is is a redstone clock. The faster the redstone clock, the more consistent the power output of the AC electric engine (and, it seems, the faster the magnetizing unit will charge a shaft core). There are two good ways to create this clock (without other mods, that is). The first is the two repeater clock.
The other is the comparator clock.
The comparator clock is faster and so produces a consistent output, but the difference in consistency isn’t usually meaningful on a practical level. What an AC electric engine can do with one clock, it can do with the other. One note about the AC electric engine: the slight fluctuation in power resulting from the two-repeater clock makes it impractical to link more than a handful of them together with shaft junctions (sparks and noise and stuff). Two work together just fine. Because of its faster rate, a comparator clock should enable you to link a lot more AC engines together in a chain than a two-repeater clock can, but I haven’t tried this out, so don’t quote me on that.
Putting It All Together
With two AC electric engines, two charged shaft cores, a boring machine, a shaft junction, a couple of chests, and the material necessary for a redstone clock, you are ready to start digging holes like Honeydew the Dwarf. If you have the steel, you may want to make a worm gear at this point, too. But once again, unless you are encountering a lot of obsidian, the two AC electric engines alone should suffice. You’ll need to set up your redstone something like this:
One last note: you will probably have noticed that I have a single chest on either side of the boring machine rather than one double chest on one side. This is because the boring machine will only output into one half of a double chest. The way I understand the problem (I’m no modder), this is actually some weirdness in the way the vanilla double chest works. So do yourself a favor and put a single chest on either side of the boring machine, or else use Rotarycraft’s scaleable chest (a post for another time, there) or something like CPW’s Iron Chests mod.
* Correction: an earlier version of this post had imperfect models for the comparator clock. This resulted in my stating that power fluctuation in the AC electric engine was inevitable. The optimized comparator clock shown in the present version of this post, however, makes the AC engine’s output perfectly stable. I also incorrectly stated that the difference in clocks had no effect on the magnetizing unit. In my experiments, the magnetizing unit charges a LOT faster with the comparator clock.