Can You 3D Print Legos? Should You Do It!


Over 600 billion lego bricks have been produced since 1949 when the Lego Group first started making toy bricks. Legos as they’re affectionately known are the most iconic toys appearing in everything from books to blockbuster movies. 

Made by injection molding molten plastic every single brick is checked for consistency in color and size by human inspectors. Only eighteen out of every million bricks fail to make the grade.

Lego bricks have to be precise if they are to easily fit together. The machines used to make them have tolerances as low as 10 micrometers. 

It is possible to 3D print Lego-compatible bricks using a 3D printer. You will need a 3D printer, a suitable filament , and a 3D model of the Lego brick. While 3D printed Legos may not have the same level of precision and quality as commercially produced Legos, they can be a fun and creative way to make custom bricks.

With such a need for accuracy, is it possible to make functional legos with a 3D printer? How much would it cost compared to just buying a set? In this article, we take a look at how practical it is to print your toys versus buying them. 

Can I Make Legos With A 3D Printer?

Conventional store-bought lego bricks are made from ABS (acrylonitrile butadiene styrene) through injection molding. ABS is one of the most commonly used raw materials in 3D printing. Making legos from a 3D printer is possible and there are several advantages to doing so, one of which is the ability to customize the design. 

Should you decide to make your legos, you would have infinite freedom to try out new designs you wouldn’t find in manufactured legos. 

You might decide to use a glow-in-the-dark filament to make luminescent legos for example. There is almost no limit to what you can do in terms of design if you decide to 3D print your legos.

The Lego Group owns the rights to the brand name and trademark. The basic bricks themselves are not under patent so you can print them to your heart’s content without fear of litigation. Some of the shapes and designs are more proprietary so you want to check before you print. Source

Lego also has the LEGO Digital Designer which is a free program you can use to design and print your own Legos. With that said, while you can print legos for personal use, you cannot call your bricks legos or advertise them as such. 

Disadvantages Of Printing Legos

While printing legos might seem like an attractive alternative to buying them, there are a couple of reasons why it might not be prudent. 

First, 3D printers are not designed for mass production. You can make a handful of legos with a 3D printer but this would quickly become unsustainable if you needed to make a couple of hundred bricks. Compared to injection molding, 3D printing is agonizingly slow. 

Speed and volume are the Achilles’ heel of 3D printing. This is where traditional manufacturing still has the edge. You can produce thousands of items in the time it takes a 3D printer to produce just one. Source

The second challenge you will face with printing your own legos is accuracy. Lego molds are made to within a tolerance of up to 20 micrometers to ensure the bricks fit together. This type of precision will be hard to replicate with 3D printing. 

Is It Cost-Effective To 3D Print Legos?

From a purely monetary perspective, 3D printing legos is cheaper than buying them. Printing involves only the cost of the material whereas the cost of overheads like marketing is added when buying. Printing can save up to 50 percent off the final cost. 

However, looking at it solely from a monetary perspective tells only half the story. You also need to factor in costs in terms of time and effort expended to produce a 3D printed lego. You will highly likely spend a lot of time on post-processing to improve the accuracy of your lego. 

What you thus save on money you lose in terms of time spent. This is especially so if you plan on producing a large volume of legos. The return in terms of money saved diminishes with each brick you print. Source

How Long Does It Take To 3D Print A Lego?

The time a 3D print takes depends on several variables including shell thickness, infill density, and layer height. A smaller layer height for example will increase the time a print takes. Conversely, decreasing shell thickness reduces the print time, but a single piece will likely take more than 10 minutes.

You can calibrate your printer settings this way to increase or decrease your print speed. The size of the print is also another factor to consider as the bigger your prints are, the longer they will take. 

Another important factor that will determine how long you will take to print your legos is post-processing. Due to the precision you need to achieve with your bricks, you are likely to take more time post-processing than you would with other prints that don’t require any precision. 

What Materials Not To Use In 3D Printing Legos?

One of the advantages of 3D printing legos is there is greater freedom in terms of what material to make them from. While in theory, they could be printed from almost any filament, it would be more practical to print using standard filament like PLA, ABS, or PETG. 

PLA is easy to work with. It is also odorless and is food safe. If you are worried about plastic ending up in your toddler’s mouth then PLA is the safest option. 

PLA however, is not as strong as ABS. If you need something that will not break easily when someone steps or sits on it, then ABS is a sturdier option. Another reason to use ABS is conventional legos are made from ABS so you would be using materials that match up.

PETG is an effective alternative to either PLA or ABS. It is as strong as ABS while being as easy to print as PLA. 

These are the best options for printing with filament. There is the option of resin printing. A resin printer would allow you to create legos with greater accuracy as resin printing produces more finely detailed parts than printing with filament. 

The biggest downside to resin printing is that it requires more post-processing so this would increase your print time.

Is It Cheaper To 3D Print Toys in General?

3D printing toys can be up to 90 percent cheaper than buying them. Printing does not carry any additional costs that are factored into the final price of a store-bought toy. The cost of printing a lego for example is up to six times less than buying one.

In a recent study, researchers from Michigan Tech found that printing toys using filament reduced the cost by as much as 75 percent. Costs went down as much as 90 percent when recycled filament was used. Source

We also highly recommend that you check out our post “How To 3D Print Logos (Or Anything)? Step By Step

sherifjallad

I am a very well experienced techie civil engineer who's extensively interested in 3D printing technology and even more captivated by the potential of 3D printing livable structures

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