How to Use the Crafter in Minecraft 1.21 for Autocrafting

In Minecraft 1.21, the new Crafter block has introduced an exciting way to automate crafting processes. This tutorial will guide you through setting up an auto crafting system using the new Crafter, along with a simple Redstone circuit to provide the necessary pulse for crafting automatically. We'll also incorporate overflow protection to ensure your system runs smoothly.

For this tutorial, we'll start with a single item auto crafter, meaning it can auto craft any recipe that uses just a single item in it's recipe (in one or more slots). Therefore, it's a Single Item, Multi Slot auto crafter.

There are other designs for two and three item auto crafters, as well as single item, single slot auto crafters. We'll cover those in a different post.

There are hundreds of single item recipes in Minecraft, such as paper or sugar from sugarcane, planks from logs, slabs from planks, bonemeal from bones, iron blocks from iron, and vice versa. A single item auto crafter is a powerful way to take your farms one step further to process the output into something useful. For example, sugar cane itself isn't terribly useful. You can now process it automatically into paper or sugar.

Another example, put one of these on your iron farm to compact the iron into blocks. Add another after the iron block storage to get iron ingots back out, saving storage space by compacting your iron into blocks.

If you put one of these on the end of a sugar cane farm, and depending on how you configure the crafter, you can get either sugar or paper. By clicking on the slots, you can configure the crafter to only fill specific slots.

Here's a crafter configured for sugar

And this crafter is configured for paper

By putting a button or a lever directly on a crafter, we can activate it manually to get a single recipe crafted.

However, the crafter has some interesting Redstone characteristics that make it easy to automate. At first, it may seem confusing, but let's break it down.

If you put a comparator on a crafter, it outputs a Redstone signal equal to the number of slots with an item in it, blocked slots count as an item. So a full crafter will output a Redstone signal of 9 through a comparator. This is useful because we can use this event of the crafter becoming full to trigger a pulse to itself to craft the item.

In the above example of a paper crafter, if there are three available slots with a single sugar cane, that will output a signal of 7. If our simple Redstone circuit activates only on 9, then it will wait for three sugar cane to make paper rather than sugar.

Here you can see we have a signal of 7 coming out of this crafter.

Building a Single Item, Multi Slot Auto Crafter

Let's make this simple single item, any number of slots auto crafter. At the end, we'll add on overflow protection.

FootprinT

This is the space required for the entire system

Materials Needed

• 1 Crafter
• 2 Chests (for a double chest output, or any storage block)
• 1 Hopper
• 3 Comparators
• 3 Repeaters
• 6 Redstone Dust
• 1 Redstone Block
• Redstone Lamp
• 2 building blocks
• 1 Lever
• 1 Composter (plus several hay bales to compost)
• Materials for crafting

Step-by-Step Guide

1. Place the Crafter

Start by placing the crafter where you want your auto crafting system to be. Ensure you have enough space around it to build the Redstone circuit.

2. Set Up the output chest

Place a chest in front of the crafter. This chest will store the output of your crafting process. It has to go on the front, or the face. The crafter can input directly into a chest.

3. Add the Hopper

Place a hopper connecting to the side of the crafter. The hopper will feed materials into the crafter. Ensure the hopper is pointing into the crafter by crouching and right-clicking on the crafter with the hopper in hand.

4. Configure the Crafter

Right-click the crafter to open its interface. Place the recipe items in the crafting grid as you would in a crafting table. For example, if you're crafting paper, place three sugar cane in a horizontal line. Click on the other slots to close them.

5. Build the Redstone Circuit

Now, let's build the Redstone circuit to provide a pulse for the crafter. Here's the entire setup. Note that while you're building this, all of the Redstone will be lit up if we have the crafter full like above. By the time it's all built, the paper will get crafted and it will look like this.

1. Put a Comparator coming out of the back of the Crafter.
2. Right Click the Redstone output of the comparator to put it into subtraction mode. The output side of this Comparator will light up. This is critical!
3. Put a block on the output of the comparator. When the Crafter is full, that signal coming out is 9.
4. Put a piece of Redstone next to the block
5. Put a Repeater aiming to the front of the setup
6. Put a block next to the crafter with the Repeater pointing into it. Once you place this block, the crafter will craft the paper. You'll see the Redstone change now that the Crafter is empty. Don't fill it up again yet.
7. Put the second Comparator pointing into the side of the first Comparator
8. Put a Composter on the input side of that Comparator and fill it all the way up so it is ready to harvest for bonemeal. Don't click it again so the bonemeal comes out. You want it to look like the picture above.

The composter thing is weird and confusing, but the reason for this is that a full composter will pretty uniquely output a Redstone signal of 8 (like a half-full chest). By putting a signal of 8 into the side of the other comparator in subtraction mode, when the crafter is full, a signal of 9 - 8 = 1 comes out of the first comparator. This signal of 1 ensures that the crafter only gets activated when the crafter it is full.

We could have instead just extended the signal coming out of the first comparator, but that would have required a line of 10 redstone wrapping around over the final block we placed. Like this, which is exactly the same. It's just less compact and much more fragile as Redstone tends to get broken.

That's it! put sugar cane (or anything that crafts with this three-in-a-row pattern, like wheat or planks) into the hopper and it will craft the items as they go into the crafter. Put a chest on top of the hopper, or put this on the output of a farm!

It's important to note that if the crafter becomes over-filled, like with more than one item in each slot, it will stop automatically crafting. This can happen if the circuit is broken while there are items in the hopper. If this happens, you need to clear it out. The auto crafting only works if the crafter is emptied after each crafting activity.

6. Add Overflow Protection

To prevent overflow and ensure the system stops crafting when the chest is full:

• Place a comparator facing outwards from the chest.
• Put this comparator into subtraction mode. When the chest is full, a comparator outputs a signal of 15.
• Put a repeater on the output of the comparator
• Put a Redstone lamp on the output of the repeater. You can use any block, but the lamp will give you an indication that the chest is full.
• Put a repeater pointing into the hopper
• Put two Redstone next to the lamp going into the repeater that's pointing into the hopper. When the lamp is activated by the comparator/repeater when the chest is full, that will turn off the hopper and prevent more items from going into the Crafter
• Put a Redstone block two blocks away from the side of the comparator and connect them with Redstone on top of the Redstone block to the side of the comparator. This puts a signal of 14 into the side of the repeater. A full chest is 15. 15 -14 = 1. Anything less than a full chest will not output any signal to the hopper.
• Add a lever to the Redstone lamp to override and turn off the hopper automatically. This is useful when reconfiguring the Crafter!

Here's the entire setup

How to Use the Auto Crafter

Put the crafting recipe ingredients into the hopper and watch it work. Remember that if the crafter gets over-filled it will stop working. It relies on the Crafter being emptied after each craft to properly create the pulse that activates the next cycle! If it stops, pause the input with the lever on the overflow and empty the Crafter, or put a button on the block next to the crafter to trigger it manually to clear it out.

Use the auto crafter on your farms

Tuck this under the end of a farm, like this sugar cane farm. In this example, the chest is not yet full.

Here's another setup at the end of a hopper minecart collection system on a much bigger sugar cane farm. In this one I moved the Redstone lamp to another spot and replaced it with just Redstone in the overflow circuit. In this picture, the output chest is full, so the lamp ls lit up.

By following these steps, you can use the new crafter in Minecraft 1.21 to automate your crafting processes with a reliable Redstone circuit and overflow protection.

Here it is in action on a sugar cane farm