Homebrew 3-D printer

I built my own 3-D printer from parts that worked great until it melted itself.

It was 2018 and I found myself in a robotics + AI Meetup. Talking to real mechanical/electrical engineers gave me maker fever. All of these years of engineering and I had never actually built anything.

If you stack bricks to make a wall, what happens at the edges? If you make four walls for a house, does the fourth edge just line up? I wouldn’t know: I’ve never built anything!

My wife expressed a reasonable amount of concern. This sounded expensive and dangerous, until I found that 3-D printer kits could be purchased from China for $150. Then it only sounded dangerous. After months of discussion, I decided to take the leap and order a kit.

A month later, the kit arrives in a cardboard box. One of the things I unpacked was a cord with a wall plug on one end and three bare wires on the other. What??? A feeling of fear and regret washed over. I was most worried that I would be out $150 and/or burn the house down. I didn’t like the idea that, even small mistakes, could cost something material. Working in the realm of bits means that you can only lose time, but working in the realm of atoms means that you can lose a circuit board or a finger.

This is the point where I started to think that I would be permanently injured

In hindsight, I should have taken some classes or read a book on electrical engineering. Fortunately, there were some very detailed videos explaining how to build the printer step-by-step narrated in Mandarin. After a few evenings of assembly, it was ready to rock. Without a multimeter to guide me, it was a leap of faith to plug the cord into the wall. I hold my breath and plug it in.

Nothing happened.

Then the screen turned on.

Then it went off again.

Then I smelled burning plastic, and saw smoke rising out of the circuit board.

I unplugged the cable and my heart sank. All of that back-and-forth to get approval, all of those days waiting for the package to arrive. I looked at where the burning came from, and noticed that some copper strands from the wires that went into the circuit board were touching. This caused the plastic cap to melt, but the board itself looked fine. With some electrical tape as shielding, the system booted fine and worked! It came with an schematic to print, a small cylinder with a Chinese symbol on it.

Does anyone know what this means?

The Good

The printer lasted for several years and is a part of a few successful and many failed projects. Building a 3d printer from scratch was an amazing experience and a cost-effective way to get into 3d printing. Being able to make almost anything is extremely satisfying.

The Bad

Cheap printers require constant maintenance because the prints stick to the cheap levelling plate, the parts are janky and weak, and the amount of assembly means that there will be things that aren’t aligned. In hindsight, I should have upgraded to a better printer much sooner. Because I didn’t:

The Ugly

Years later, while I was asleep, the heat finally melted away the tape I had forgotten about and the circuit board was completely annihilated by 120 volts of raw, sustained energy. This caused the entire garage to fill with toxic smoke and an acrid smell that never fully went away. This is probably what the fifth circle of Dante’s Inferno smells like.

The Takeaway

Beyond the satisfaction of building an electrical appliance from parts, I still have this awesome set of screw-puzzles.