Leitner Boxes: When 3D Printing Gets Useful

Sometimes the best projects are the ones that help your family

My 3D printer has been sitting idle for a while now. Not broken, not forgotten – just... waiting. Between work and life, I hadn't found a project that sparked that creative itch. Until this Christmas holiday, when my son mentioned his upcoming English exam and a pile of irregular verbs to memorize.

The long road here

I've been into 3D modeling and printing for more than 15 years now. It started with a very specific goal: printing custom Blood Bowl figurines. Back then, owning a printer wasn't really an option, so I used Shapeways – uploading my designs and receiving them in the mail weeks later. The anticipation was part of the magic.

Eventually, I got my hands on an Ultimaker. No tutorials, no safety net – just trial, error, and a lot of failed prints. But with each failure came understanding, and slowly, I learned the craft.

Some years ago, just before the pandemic, I bought an Ender 3 v2. That printer saw a lot of action – mostly printing Playmobil accessories and vehicles for the kids. Little cars, tiny furniture, custom pieces that brought their imaginative play to life.

But these last couple of years? The printer gathered dust. Too busy, too distracted, too many other priorities.

Enter the Leitner box

For those unfamiliar, a Leitner box is a brilliantly simple learning system. You organize flashcards into compartments based on how well you know them. Cards you struggle with stay in the first compartment and get reviewed frequently. As you master them, they graduate to later compartments with longer review intervals. It's spaced repetition made tangible.

My son had already prepared index cards with irregular verbs. He just needed the box system to make the learning method work. And suddenly, I had my project.

OpenSCAD and 15 hours of printing

I fired up OpenSCAD – my modeling tool of choice – and started designing. The beauty of parametric modeling is that you can adjust compartment sizes, wall thickness, and dimensions until everything just works.

Fifteen hours later, the Ender 3 v2 delivered. The box came out perfectly – sturdy compartments, smooth walls, everything fitting together as designed.

The best reward

The look on my son's face when he saw it? Worth every minute of design and printing time.

But then my wife looked at it. "This is really useful," she said. "Can you print two more? All three kids should have one."

And just like that, my printer is back in business. Not printing toys or novelties – printing tools that help my family learn and grow.

Sometimes the best projects aren't the most complex or the most impressive. They're the ones that solve a real problem for the people you care about.

What's next?

The Ender 3 v2 is back on active duty. I'm already thinking about what other useful things I can design and print. After years of printing fun accessories, it feels good to create something genuinely practical.

Plus, I have two more Leitner boxes to print. My printer and I have work to do.

What projects brought your maker tools back to life? I'd love to hear about useful things you've designed for your family!

Cheers,

Horacio Gonzalez - LostInBrittany