Last post I made the tech-tree leap in Rotarycraft into bedrock dust and all of its wonders. But the way I did it, using Industrial Coils, was not really ideal. Even though it works, the Industrial Coil solution has some pretty serious inherent problems: 1) it only goes so long before it needs to be recharged, and 2) it’s really expensive in terms of iron. As I noted, the expense in terms of iron isn’t a deal-breaker, since Industrial Coils are super useful in a lot of different contexts (I’m working on a couple of models for Rotarycraft tree farms, one of which will use Industrial Coils). But the best solution for powering the Bedrock Breaker (and the solution that Reika really intended) is the Microturbine.

The Microturbine produces 2.097 MW of power at an astounding 131,072 rad/s, but with only 16 Nm of torque.

Using the Microturbine, though, requires some things I haven’t talked about, yet, namely jet fuel and diamond gearboxes (though there is a way around the latter, which I will show in a following post).

Making Jet Fuel

Nothing I’ve shown in Rotarycraft so far has required any materials from the Nether. That changes with the need for jet fuel. Rotarycraft jet fuel is made in a block called the Fractionation Unit.

The Fractionation Unit converts six different fuels and nether materials into jet fuel, which is needed to power the Microturbine and the Gas Turbine.

The Fractionation Unit uses blaze powder (use the Grinder for more blaze powder per blaze rod), magma cream, netherrack dust (made by processing netherrack in a Grinder), tar sand (made by processing soul sand in a Grinder), coal, and ethanol. It also needs one ghast tear as a catalyst (so the ghast tear won’t ever be used up). Fortunately, the Fractionation Unit uses up these materials (except the ghast tear) somewhat slowly (one or two items among the six are used each cycle), and every cycle appears to make between 1.5 and 2 buckets of jet fuel. So a stack of each kind of item will make a lot of jet fuel, and pretty quickly.

The Fractionation Unit’s GUI. If you’re observant, you will have noticed in the background that I have liquid pipe rather than fuel line above the Fractionation Unit. It no work.

Powering the Fractionation Unit is a piece of cake. It needs 65 kW of power at 8.192 krad/s, so a Gasoline Engine with a 16:1 gearbox on speed mode does the trick. To pump jet fuel out of the Fractionation Unit (into a reservoir, for example), you need to use fuel line rather than liquid pipe (6 obsidian and 3 glass make 16 on the worktable). The Fractionation Unit pumps out from the top and receives power from the bottom.

A Fractionation Unit powered by a Gasoline Engine and a 16:1 gearbox in speed mode, outputting jet fuel through fuel line into a reservoir.

To power the Microturbine with jet fuel, you can either feed jet fuel directly into it using a fuel line or you can right click on it with buckets of jet fuel (I recommend the latter, at least at first). Unlike the other engines we’ve dealt with so far, the Microturbine takes a little while to spin up to its top speed. During this “warming up” period, it uses jet fuel at an alarming rate. However, once it has fully warmed up, the Microturbine’s consumption of jet fuel slows way down. This means that the Microturbine is not best suited for small jobs or things that demand immediate power. Rather, it should be used for processes that are either ongoing or are going to take a while.

Transforming the Microturbine’s Speed into Torque

The Microturbine produces 2.097 MW of energy, which is what the Bedrock Breaker needs, but it’s completely the wrong kind of energy: high speed, low torque, where the Bedrock Breaker needs very high torque. You need to change the Microturbine’s 16 Nm of torque into 8.192 kNm of torque (or 2^4 into 2^13). In other words, you need some combination of gearboxes that equals a multiplication value of 512 (= 2^9). Some options include: 1) nine 2:1 gearboxes; 2) four 4:1 gearboxes and a 2:1 gearbox; 3) three 8:1 gearboxes; or 4) two 16:1 gearboxes and a 2:1 gearbox. Any one of these combinations will work just fine.

BUT, you can’t use steel gearboxes, at least for the first and last parts of the series. This is because, with the exception of bedrock shafts, each kind of shaft material (wood, stone, steel, diamond) has a limit to the speed or torque that can enter or leave it. The speed limit for steel shafts (and gearboxes) is 55,207 rad/s – less than half of the speed of the Microturbine (= 131,072 rad/s). This means that a steel shaft or gearbox cannot receive shaft power with a speed above 55,207 rad/s, nor can it transform its input into anything faster than 55,207 rad/s.

To illustrate this last point, say a steel 2:1 gearbox is receiving power whose speed is 32,768 rad/s. If that gearbox is set in speed mode, it will try to multiply that speed by two, making an output speed of 65,536 rad/s. This is higher than the steel shaft limit, though, so just as the gearbox will explode if it receives power at 65,536 rad/s, it will also explode if it tries to output power at 65,536 rad/s. Unfortunately for us, 131,072 rad/s far exceeds the limit for the steel shaft. Furthermore, steel’s torque limit (6711 Nm) ) makes it so that we cannot use steel at the end of the conversion. We’re going to have to look into diamond gearboxes for at least the first and last parts of the conversion.

Now for a little confession: a small part of the reason why I didn’t talk in-depth about the Microturbine solution in the last post was that, in my survival world, I don’t have many diamonds. I’ve been tunnelling the bat guano out of the bowels of the earth beneath my base (using the Boring Machine) and have encountered a remarkably small number of diamonds. Plus, I was under the false impression that the diamond gear recipe was essentially the same as the steel gear recipe (5 steel ingots = 3 steel gears). If that had actually been the case, to make two 16:1 diamond gearboxes and a 2:1 diamond gearbox would have cost me 56 diamonds. Iron I had tons of. Diamonds, not so much.

But this is not the case. The diamond gear recipe in fact uses 5 diamonds to make 8 gears, not 3. Moreover, you don’t have to use diamond gearboxes for the whole transformation. You can, in fact, get by with as few as 11 diamonds (leaving you two extra diamond gears, too). Here’s how.

First, use 2:1 gearboxes instead of anything denser. One 4:1 gearbox may do the same thing as two 2:1 gearboxes, but it does so at an extra cost of  two diamond shafts (= two diamonds), even if the steel cost is lower (by 5 steel ingots). Second, you only need diamond gearboxes until your speed is below 55,207 rad/s. The first 2:1 diamond gearbox reduces the speed to 65,536 rad/s, and the second to 32,768 rad/s, at which point you can use steel until the last 2:1 gearbox (whose torque output of 8,192 Nm will exceed the steel limit). So I suggest this setup, or something like it: Microturbine – 2:1 diamond gearbox – 2:1 diamond gearbox – 4:1 steel gearbox – 16:1 steel gearbox – 2:1 diamond gearbox – Bedrock Breaker (or Bevel Gear(s) – Bedrock Breaker). The diamond gearboxes do need lubricant to operate (one bucket), but unlike wood, stone, and steel, they never use it up. And now that gearboxes retain their lubricant when broken (as of v25), you only ever have to lubricate a diamond gearbox once!

Probably the cheapest way to use a Microturbine to power a Bedrock Breaker: (from right to left) Microturbine – 2:1 diamond gearbox – 2:1 diamond gearbox – 4:1 steel gearbox – 16:1 steel gearbox – 2:1 diamond gearbox.

With this setup, you’re ready to do some Bedrock Breaking for a much more extended period of time than the Industrial Coils allowed. Just make sure the Bedrock Breaker is pointed horizontally, give the Microturbine 15 to 20 buckets of jet fuel (at least), and wait for the bedrock dust to come wafting in.

A Final Note: Using the Microturbine for Making Tungsten Ingots

The Microturbine is also the intended way to power a Friction Heater when smelting Tungsten flakes. To do this you would need at least another 2:1 diamond gearbox to produce the minimally required torque of 32 Nm (this is a use for those two extra diamond gears I mentioned earlier). But this by itself, won’t get the Friction Heater up to the required 1350 degrees centigrade, because the Friction Heater works best when its input torque and rotation speed are close to equal.

I’m using a Microturbine and a 2:1 bedrock gearbox to power a Friction Heater outside in a forest biome. The temperature only gets to 990 C because the torque and speed are so far from each other, even though the total power in Watts is identical to that of two Industrial Coils on max output. More gearboxes would be needed to make this work.

You can use a series of gearboxes to make the Microturbine work, but I actually prefer using two Industrial Coils for this task. Aside from the fact that I don’t have to use gearboxes with Industrial Coils, the main reason is something I said earlier in this post: the Microturbine doesn’t lend itself well to small jobs. But the rarity of Tungsten flakes means that smelting Tungsten ingots is always going to be a small job. The way I play, I cannot imagine that I would ever find myself in a situation where I have a stack or two of Tungsten flakes and need to smelt them all at once. You neither acquire nor use Tungsten in this way in Rotarycraft. I think the two Industrial Coil solution fits this particular need just fine, while I feel like I would have to go out of my way to use the Microturbine. It’s a matter of personal preference, I think. Or, if you play Rotarycraft in a fundamentally different way from what I do, you might find that the Microturbine is precisely what you need. It just isn’t what I need to smelt Tungsten.