Introduction: GLaDOS Potato Replica (with Lights)

Portal 2 is one of the greatest puzzle games of this century. It takes a very simple principle, two linked portals that you can pass through, and applies it to increasingly complex puzzles. However, it owes its success in part to its witty and engaging storyline, the highlight of which is when GLaDOS, your tester and tormentor, gets transformed into a potato. trapped in such a simple form, your longtime enemy is forced to work with you, providing sarcastic commentary along the way. Turns out, it's incredibly easy to recreate potatOS, so let's get started!

(Acerbic personality not included)



- 3mm red leds (x2)

- 5mm yellow led (x1)

- CR2032 button battery

- 1kohm resistor (x2)

- Medium nail* (x2)

- Alligator jumper leads (x2)

- No. 2 wire

- Electrical tape

- ~5g of white PLA 3d printer filament

- ~2g of black PLA 3d printer filament

- A single potato

*pick the size based on your potato


- 3d printer

- Soldering iron, solder, sponge, helping hands (optional)

- Pliers

Step 1: 3d Printing

The most time-consuming task in the project is 3d printing the plastic parts on GLaDOS. I designed them in tinkercad to fit most potatoes. I found 35mm to be the best looking on the majority of the potatoes I used, but it may need to be scaled up or down based on your potato. They can be printed at any layer thickness, I used 0.2mm, and only the centre eye needs supports. I've included two ready-to-print collections of all the white and black parts, and also have them individually if you need them.

Once both sets are printed, superglue the chip legs to the chip as shown.

Step 2: Finding a Potato

While this may sound like an incredibly simple step, it's worth mentioning for two reasons: first, the closer the match to the game model is, the more recognizable the finished prop will be. Secondly, the experience of going through checkout with nothing but a single solitary potato is incredibly amusing, and the cashier will likely get a good laugh out of it.

Step 3: Wiring

If you want GLaDOS to light up (and honestly, why wouldn't you,) you're going to need to include a simple circuit, consisting of 3 LEDs. To power it, we're using a common CR2032 cell battery. This gives us around 4 hours of battery life. It would be possible to use more than one of these batteries in parallel, but it's somewhat difficult to fit them all into the enclosure, so one is ideal. To start with, bend the legs of a 3mm led 90 degrees, then firmly press it into the hole in the chip. I had to drill these holes out slightly to make the LEDs fit. Once it's in place, cut off the long leg (positive,) and solder a 1k ohm resistor onto it to dim it.

Next, bend the legs of the yellow led so that it forms a kind of a C shape (see photos.) The aim is to create a cradle for the battery. Solder the negative leg of the LED to the top (negative) face of the battery (see photos.) You might have to try a few times to get the solder to stick

Finally, solder the negative end of the chip LED onto the same spot as the negative leg of the yellow LED. The third LED is connected the same way. I accidentally burnt out my second red led by holding the iron on it for too long. Don't do that; I screwed up so you wouldn't have to.

If you've wired it right, you should be able to touch the positive leads of the LEDs to the positive face of the battery and be rewarded with pretty lights. If they don't light up, double-check your connections, and make sure that the LEDs are the right way around.

Step 4: Putting It All Together

Almost at the finish line now, all that's left is to assemble everything and add the finishing touches. The led assembly needs to be hot glued to the center eye. Be careful here, I managed to melt the thin layer of plastic that the LED shines through. Finally, take some electrical tape and stick the bottom led contacts firmly to the battery. Use tape instead of solder so that there's one less thing to disconnect when you swap the battery.

Once that's held in place, we need to make space in the potato for it. Mark out an area the size of the battery, and carve it out using a small paring knife. No need to go all the way through, just so the battery fits snugly. When enough room has been cleared, slot the battery in place. Firmly push the chip into place, the legs will penetrate the potato and stick there. Push the short legs of the staples through the holes of the eye and into the flesh of the potato to secure it.

Step 5: The Finishing Touches

All that's left to complete GLaDOS is the alligator clips and nails. Find two suitable nails and press them into the potato, so they stick up about 2cm, one just below the chip and another at the bottom of the potato. That's where the clips will go.

Now, bend some baling wire into the approximate shape of a bent U (see pictures.) We need three of these. Insert one into the potato just above the chip, and another midway between the bottom nail and the center eye. The third one goes on later.

Cut the alligator leads long enough to loop to the center eye, and loop them through the baling wire. The final u shape of wire goes right up close to the red clip (see photos.) Use a drill bit that's slightly smaller than the wires to create two holes, then push the wires into the potato.

Now, while it looks alright as it is, to really complete it we need to color in the recessed parts of the center eye. This can be done with a regular sharpie and some finesse. And with that, we're done!

"So, how are you holding up? Because I'm a potato!" - GLaDOS

Potato Speed Challenge

Runner Up in the
Potato Speed Challenge