This post is kind of a two-fer: it’s about Rotarycraft AND simple redstone devices.

When playing with Rotarycraft, one of the things you really want to make fully automatic is lubricant production, because you will need lubricant and lots of it. I’m sure there are many fantastic ideas out there about how to automate lubricant production. I’m not going to pretend that my system is the best or the fastest or the most economical. But it sure was fun to build, and it provides me with an opportunity to talk about the RS latch, one of a couple of kinds of redstone logic gates we call memory cells (because they “remember” an input).

An overhead view of a simple RS latch. The two oak planks blocks with buttons represent the inputs and the glowstone lamps represent the outputs.

When the left button is pushed, the far output is activated and remains on until the right button is pushed.

Conversely, when the right button is pushed, the near output comes on and remains on until the left button is pushed.

Back to lubricant production. This is a general overview of the system: I am using Rotarycraft’s Fans to automate the planting and harvesting of canola, the plant whose seeds when ground by Grinder produce lubricant. An Item Vacuum collects the seeds and sends them, via a Pneumatic Item Pump line, to a pair of Grinders that are powered by Wind Turbines. I use hoppers to distribute the canola seeds between the two Grinders. But my canola seed production very easily outpaces my Grinders ability to process the seeds, so I use a redstone comparator to read how full one of the hoppers is that distributes the canola seeds. When it is full, the output reaches a repeater that acts as one of the inputs on an RS latch and turns off a clutch connected to the Fans for my canola farm and cuts off production of the seeds. As the Grinders do their work and the canola seed supply within the hoppers dwindles (no longer being resupplied by the canola farm, for the moment), the comparator’s signal shrinks, eventually to the point that a NOT gate is no longer receiving a redstone signal. This NOT gate then sends an input to the other side of the above-mentioned RS latch, turning canola production back on. In this way, the canola farm only operates when it needs to but is still fully automatic in its turning on and off.

Now, let’s look at each element a little more closely.

I’m using Fans for canola harvesting and replanting. I realize I have more fans than I need, but I haven’t taken the time to streamline this farm, just yet. Notice the clutch in the middle left part of the screenshot. This clutch is turned on and off by an RS latch below ground.

Eight wind turbines produces 32 kW at 32 Nm, enough power, when converted using gearboxes, to power two Grinders.

In this small room just above the ceiling of my lubricant production room, I take the 32 kW at 32 Nm produced by the eight Wind Turbines and divide it into two equal lines (using a shaft junction) before sending it down into the lubricant production room.

The power of the eight Wind Turbines comes in via the two stone shafts you see on the right some of top-center. At this point, each line is 16 kW of power at 16 Nm of torque. I send each line through an 8:1 gearbox, transforming the torque into the required 128 Nm. Canola seeds from the farm above are sent into the hoppers through Item Pumps. The Grinders receive canola seeds from the hoppers and output lubricant directly into lubricant lines.

This is a fun little setup with four hoppers. The Pneumatic Item Pump line injects directly into the hopper on the left (behind the comparator). Notice that this hopper is directed toward the hopper to its right, which is itself directed toward the hopper to ITS right. The right-most hopper is pointed down toward the right Grinder. A fourth hopper sits below the first hopper and is directed into the side of the left Grinder. With this setup, the first hopper is able to eject canola seeds into two different hoppers and supply both Grinders.

This is an RS latch in room in front of the two Grinders. The comparator from the last image outputs a redstone signal whose strength is dependent on how full the first hopper is. When it is completely full, the comparator output looks like this. It has reached the repeater on the far end of this room and powered one of the inputs on the RS latch. The RS latch’s output now depowers the Fans in the canola farm above. Gradually, the comparator output will shrink. When it shrinks to the point that is only powering the piece of redstone that sits behind the cobblestone on the left side of this screenshot, a redstone torch on the other side of the cobblestone will no longer be de-powered and will send a signal through another repeater (middle left of the image). This signal is the RS latch’s second input, and this changes the output so that the canola farm above is activated and starts producing canola seeds again.

Looking at the RS latch from the other direction, back towards the Grinder room. The redstone torch in the middle of the image is a NOT gate. When the comparator signal weakens sufficiently, this torch will turn on and change the RS latch’s state, ultimately turning on canola production above.

This looks at the RS latch from above. The input associated with the hopper being full is currently active (on the right side of the screen). For reference, the room with the Grinders is to the left.