Skip to Content

Why Do 3D Printers Still Use SD Cards? 7 Reasons

USB drives are used for almost all our day-to-day technological needs, so it can be surprising to find out that many 3D printers can't read external USB drives. Instead, they rely on SD cards.

Written by:
Last updated:

USB drives are used for almost all our day-to-day technological needs, so it can be surprising to find out that many 3D printers can’t read external USB drives. Instead, they rely on SD cards. 

3D printers use SD cards because they’re easier to implement than USB drives. Reading USB drives implies extra development costs. SD cards are also smaller, cheaper, and more convenient to leave in a printer for a long time. Today, SD cards are the de facto standard in many devices. 

If you don’t understand why using SD cards would benefit 3D printers, this article will clarify all your doubts. You’ll learn about some of their advantages and whether USB drives are actually better than SD cards. 

Why 3D Printers Use SD Cards

You can connect most 3D printers to a computer via USB cable. But when it comes to reading external hard drives, only a few can handle USB drives. You’ll see SD slots much more often in 3D printers. 

Although not as powerful as USB drives, SD cards offer a few advantages that make them a default choice. Let’s go over a few of them: 

1. SD Readers Are Easier To Implement

If you’re going to remember only one reason, let it be this one. Implementing a USB drive comes with extra work and investment in both the hardware and software departments. 

SD cards can be accessed using a protocol called SPI. Most microchips, like the ones inside 3D printers, have that functionality built-in. That means that manufacturers have to spend very little work and money to make their printers read SD cards. 

On the other hand, USB drives can require extra hardware to make them readable by the 3D printer. The printer will also need a software driver that lets it access that information. 

For these reasons, many manufacturers decide not to incur the cost of developing a printer that can read USB drives. 

But this wouldn’t work if SD cards weren’t so convenient. SD cards have other advantages that make them even more practical than USB drives in many situations. 

2. SD Cards Let You Print Without a Computer

We already saw that adding the feature of reading USB drives can be a hassle. You can use your computer to send files to your 3D printer, be it via USB cable or wireless. However, this comes with its issues. 

Using your computer to print means it has to remain turned on during the entire process. If you’re using a laptop and a cable, you won’t be able to move it. It also increases the chance of an accident. 

Some 3D printers can receive files over a Wi-Fi network, but they’re usually more expensive. Besides, it still means your computer needs to be working. 

SD cards are a cheap solution that lets you use your 3D printer without a computer. If you’re printing a lot of stuff for a long time, it’s good to know that there aren’t other variables that can make the process go wrong. 

3. 3D Printing Is Slow

3D printing can be very slow. Complex objects can take a lot of hours to print without any interruption. This means that if you plug in a USB drive, you won’t be able to use it during the whole process. 

If you’re printing a lot of stuff in a row or using your printer frequently, you’ll need an external drive dedicated only to the printer. In this situation, an SD card is often handier than a USB drive. 

Since SD cards are cheaper and better adapted to a single-use, you can just leave the card in place and forget about it. However, you might want to use your USB drive for something else. 

4. SD Cards Help Avoid Accidents

SD cards fit entirely inside the 3D printer. That means there’s no risk of accidents. 

If you were to use a hard drive plugged in with a cable, there’s always the risk of it falling or disconnecting by accident. Remember, the hard drive is going to stay there for a long time. 

A small pen drive doesn’t have that issue, but it’s still slightly more likely that someone unaware that it’s in use will disconnect it. 

Disconnecting your drive or moving your 3D printer while it’s at work is something you’ll want to avoid at all costs. One slight shake could ruin the print and make you start all over again. 

multiple sd cards

5. SD Cards Are Cheap and Convenient

SD cards are cheaper than USB drives. If you need several external hard drives to use for 3D printing, going for SD cards will save you money. 

Beyond that, 3D printers use SD cards for the same reason other devices do it: they’re small and convenient. They’re merely the width of a couple of credit cards, and MicroSD Cards are only 15 mm (0.6 inches) long. 

6. 3D Printers Don’t Need High Speeds or Large Storages

Even if SD cards are easier to implement in the printer, it could be worth it if it improved the process in some way. After all, USB drives can be faster and hold more storage. 

However, heavy 3D models for printing might not go over 10 MB. You won’t get much benefit from plugging a 4TB hard drive into your 3D printer, even if there’s an entire collection there. 

Regarding transfer speed, we already talked about how slow 3D printers can be. Speed isn’t an issue. And in any case, SD cards and USB drives show roughly the same transfer speeds in the low and mid-end. 

Since 3D printers don’t benefit that much from the advantages USB drives may offer, many manufacturers don’t bother adding the feature, especially if they’re trying to cut corners to create an affordable machine. 

7. Many Devices Use SD Cards

SD cards are used throughout a variety of devices like:

  • Cameras 
  • Smartphones 
  • Video game consoles 

Using many high-end cameras requires having a large number of SD cards at hand. 

This makes SD cards easy to find and widely available. Any 3D printer user who doesn’t have an SD card can buy one for cheap. 

Of course, many recent computers don’t have an SD card slot. This can be slightly inconvenient, but buying a USB dongle with an SD card slot is just as easy. 

In all likelihood, the user of a 3D printer will have at least one SD card lying around. This being the case, many manufacturers might decide they’re better off saving themselves the trouble of implementing USB connectivity. 

What SD Cards Are Used for in 3D Printing

It helps to understand why 3D printers need SD cards at all. The process of printing a 3D object starts with modeling it on a computer. 

Some of the most popular modeling programs used for 3D printing are:

  • Tinkercad 
  • CraftWare 
  • Astroprint 

However, you can also use general 3D modeling software like Blender. 

However, the 3D printer can’t interpret the model and print it as it is. This is because 3D printers function by dropping plastic into a print bed to create the layers. It puts layer over layer until the object is finished. 

So, the 3D printer needs a “sliced” version of the model that can be printed this way. 

Slicing software does precisely what its name suggests. It slices your 3D model into hundreds or thousands of layers. Since 3D printers can’t print plastic in thin air, the program also adds any necessary latticework and columns, so all the layers are always connected and supported. 

Now you finally have a file that the 3D printer can decode. The only thing left to do is move the file to a 3D printer. 

There are a few ways to do that. Most 3D printers have worked with at least one of the following: 

  • Plugging a USB cable. Some printers offer the possibility of connecting a USB from your computer to the printer. This will work just fine, but it means you won’t be able to move your computer, and there’s always the chance of accidentally unplugging the cable and shaking the printer. 
  • Wireless connection. A few 3D printers offer wireless connectivity. The main disadvantage is that transferring files might not be as fast as with a physical connection. Also, the computer needs to stay on during the whole process. 
  • External drive. This includes USB drives and SD cards. This method adds the additional step of transferring your files to the external drive, but the convenience of not needing a computer is usually worth it. 

As you’ve seen, SD cards can be the best choice of external drives in many cases. You can connect most printers via USB cable, but only a few 3D printers can read external USB drives.

Printing wireless can be more convenient for occasional, short jobs, but an external drive is overall more reliable. 

Are SD Cards Better Than USB?

SD cards and USB drives have different uses, and thus it doesn’t make much sense to proclaim one is better than the other. They don’t compete with one another and are chosen for different reasons. 

SD cards aren’t necessarily better than USD. USB drives are at times faster and can have larger storage sizes. SD cards are smaller, cheaper, and easier to implement in a device, though. USBs drives are better for moving and storing files, but many devices benefit from using SD cards. 

If you’re going to move your files, want very fast transfer speeds, or need large-capacity storage in the long term, then USB drives are undoubtedly the better choice. These are the most common situations for storing files, so USB is more commonly used than SD cards. 

On the other hand, if you’re using a portable device without much space to spend on a hard drive, then SDs can be much more practical. MicroSD occupies almost no space and is optimized to stay inside a device. 

In some instances, managing files is more efficient when using SD cards since you can have many without spending a fortune. 

Take the case of high-end cameras. Raw video can take up space very fast. Instead of having to move your files out of the device each time you run out of space, you can just switch your SD cards.

Are SD Cards Outdated?

The short answer is no. Plenty of devices still use SD cards, including cameras, smartphones, video game consoles, and smart devices. For the most part, these are devices that require storage in a very small footprint.

As we saw before, SD cards can outdo USB drives when it comes to their size. SD cards are easy to store once they’re inside a device, and they’re less prone to having their connection pins damaged. 

SD cards aren’t outdated. Older models are discontinued, but their technology is still improving to achieve faster speeds and larger storage sizes. Many devices like cameras, smartphones, and video game consoles still rely on SD cards to function. 

However, there have been a lot of changes in SD cards throughout its history. Each version has improved its capacity and transfer speed. SDSCs, the oldest type, are mostly discontinued today. 

These are the five families of SD cards: 

Card TypeMaximum SizeMaximum Bus Speed
SD Standard Capacity (SDSC)2GB25 MB/s
SD High Capacity (SDHC)32GB50 MB/s
SDXC (SD eXtended Capacity)2TB312 MB/s
SD Ultra Capacity (SDUC)128TB985 MB/s
SD Input/Output (SDIO)Used for adding functionalities rather than storage

As you can see, SD cards are powerful enough to handle the needs of many modern devices. 

The current highest transfer speed rolled out in 2018, and an upcoming protocol allowing up to 3938 MB/s was announced in 2020. 

It’s safe to assume that SD cards will keep improving and won’t become outdated anytime soon. 

Final Thoughts

SD cards are far from being outdated. They’re getting faster and more capable every year, all without abandoning their conveniently small size. 

Implementing the necessary hardware and software to read USB drives in a 3D printer can be costly. For that reason, many manufacturers decide to take advantage of the small footprint and low price of SD cards. 

3D printing is a slow and delicate process, so you’ll benefit from being able to use your printer without having to plug it into a computer. 

Written by:
Last updated:

About Ben

I started 3D printing since 2013 and have learned a lot since then. Because of this I want to share my knowledge of what I have learned in the past years with the community. Currently I own 2 Bambulab X1 Carbon, Prusa SL1S and a Prusa MK3S+. Hope you learn something from my blog after my years of experience in 3D printing.