March 19, 2023

Portal 2 PotatOS

(Sorry… STL Files for this project are not available at this time.)

So if you have no idea what this is you probably grew up under a rock (or are not a gamer).  This is a character from one of my all time favorite video games… Portal 2.  (Spoilers incoming)  For those of you who grew up under the rock the main antagonist in the game is a computer called GLaDOS. (Genetic Lifeform and Disk Operating System) and during the game your other adversary Wheatley turns GLaDOS into a Potato Battery hence the nickname PotatOS.

I’ve always wanted to make one of these but never got around to it…  recently my girlfriend bought a bag of Science Lab related stickers for a function at her work and this is what I found in the bag. The sticker was a sign to me that it was finally time to make one of these for my desk to go along with some other Portal stuff I already have.

Plus with my recent discovery of these cheap  sound module that I used on my Bomb Release Switch project it got me to thinking I can actually make it more than just a static display piece….

Now there are a few files kicking around online to print these already but I really didn’t like any of them as I wanted something a little more potato’e looking.  So to start I imported the original game files into Fusion 360 and set out to design my own version just using the original as a baseline.  My design is about 95% accurate, somethings were changed to make it easier to print and well lets face it… game files don’t always conform to real life physics (so to speak) so somethings just needed to be changed to make them actually fit.  I only designed the bits that were to be 3D printed… some of the parts like wires and clips will be real so I didn’t bother with those pieces in Fusion.

The first thing I printed was the little micro chip. I printed everything separate (because of color changes and it was just easier) and then just super glued the parts together.

The main piece of the chip was painted with a rough finish to make it look old and used. This part in the game had two LEDs but I just painted the tiny one on to make life easier.

The chips legs were then glued to the bottom into tiny recesses in the part.

Add added a black base for looks and to hold the legs in place a little better.

A tiny LED and wires are then glued in place.

Here is what the finished chip looks like.

Next it was onto the Processor (or Eye?) This was printed in two colors so finishing would be easier. This part should also have two LEDs, the main center would will be yellow and at 2 o’clock there normally would be another tiny red LED but this is where I chose to put a switch. If you haven’t figured it out (the sound module) she will talk.

I gave this a rough coat of paint too but may go back and clean it up a bit still.

For the main yellow eye part I will be using a Piranha LED and I made a hollow lens to go with it.  I printed the lens out of clear filament then scuffed up the front and will paint it yellow later on.

The Lens and LED will be glued into the back of the Processor piece along with some alignment pins and maybe some magnets.

The switch to activate the sound module is a small micro push button type switch…

… which will also get glued into the processor piece as shown.

I will paint the button red later to simulate the original LED.

Next it was time to print the Potato. The main piece has a lot of holes designed into it so we”ll have to see how well it prints.

I printing this in clear filament just to use up that roll as it was getting old but this turned out to be a bad idea because it was hard to see all of the holes and where all the other detail parts will go.

A quick test fit to check how everything fits so far.

After some sanding, filler primer, more sanding, then some spot gazing putty, then some more sanding… it is ready to paint.

I used some Raw Sienna lightened with some white for the base coat. (Notes for me in case I make another one.)

I did use a real potato as a color reference… at least to get close enough.

Not to bad for the base coat I guess.

Next to add some detail I used Burnt Umber.

This is the first Potato I’ve painted so it’s not the best but not to bad for a first try I guess.

I missed some layer lines but they show up more on camera than to the naked eye.  I also sprayed on some clear coat after so it has a shinny finish.

For the little sprouts I made these with some black PLA filament by just heating it up with a lighter and pulling until it stretched out.

Now it was time to start adding detail. The wires are bend from .041 stainless steal wire.

The nails I just had laying around.

I forgot to design in a hole for the chip’s LED wires so I just drilled one before installing the chip to the body.

I glued on some small magnets to the body and the processor. Hopefully these will be enough to hold it in place, I want to be able to remove it if I ever need to fix the wiring or something along that lines. We’ll have to see if it holds up with all the wires attached though.

For the all of the cables I will be using a variety of different wires.  I am sacrificing a few test leads (well at least one anyway) for the clips,  I have some other yellow 22 AWG wire for the straps,  and a piece of stiff solid core Romex wire for at least one of the leads that go to the one of the nails.

These are tiny 3D printed simulated connectors that will go onto the wires leads that go to the nails.

Here are the finished wire leads ready to be installed.

After thinking about things…  instead of the yellow wires going into the side of the processor I went back and redesign it to add some groves into the bottom.  This way I can hopefully glue the yellow wires to the potato body and then the processor can sit on top of them allowing me to later remove it if the need arises.

The wire I used is great in that it is super flexible but unfortunately it has a silicone rubber insulation and the super glue I am using will not stick to it… so its on to Plan B.

Lucky enough I had some Yellow PLA filament and with a little help from a heat gun and a lighter I could heat it up and bend it to fit the shape of the potato pretty well and the super glue should hold this stuff in place.

One down… two more to go.

Well it was a bit of a challenge to form and glue on all three with out screwing up the paint but I did a pretty good job of it.

Getting the processor to fit required a bit of filing as I didn’t align the wires as well as I would have liked.

When I redesigned the processor for the wires I also cut grooves into the potato to help align the wires but at that point I wasn’t going to reprint and repaint the body so I had to wing the placement.

It’s a little hacked up but not really that noticeable as it’s not a focal point of the overall project.

Next it was onto installing the power wires. The clips I had are a little to big compared to the model but they will work for now.

I used the stiff Romex wire for the longer one so it holds its shape.

The processor wires were the last to install.  I used flexible wire for the 4 on the top and Romex for the front to help hold the Processor down.  All of them are just snug fit in place so I can remove them.

I still have a ways to go before it’s finished but so far I’m very happy with how it is coming out.

Next I need to design a base to hold the sound board and battery.

I was originally going to stuff everything into the potato body by mounting the board and speaker onto a plug that just slid into the bottom but getting at the USB port and switch would have been a problem not to mention how to handle the wires for the LEDs and switch.  I think the speaker my still go into the body but as mentioned the board and battery will just mount into the display base that I will design next.

Today I figured out how to project sketches around the body so I could cut grooves for the wires… this should make attaching them really easy if I do another one of these.

This is the design for the base.  It is based off of part of the Aperture Science Core Input Receptacle and is what you use at the end of the game to put PotatOS back into the GLaDOS body so I though it only fitting to include it as part of this project.

Here are the actual printed parts of the base… as before I designed the center post in multiple pieces with color changes for easier finishing.

Here is the assembled center post assembly after painting the center piece white.

The bottom of the assembly has a channel for the wires to run up to the Potato.

Here’s the base after a little textured paint and some added detail with the airbrush to make it look like old metal.

With the base painted it was time to work on adding the sound module. It comes as 4 pieces… the main board, the 3.7V battery, a small speaker, and the switch (off screen here). The first three parts look like one assembly but they are just joined onto a single piece of double sided tape and are easy to separate as see here. Now I want to draw power for the LEDs I will be using on the potato from the same board/battery so I had to probe around to find were I could add some wires.  For the negative side I just soldered another lead right to the negative coming from the battery terminal and for the positive wire I added a wire off of one of the tiny switch connections (and when I say tiny I mean ₜᵢₙᵧ ) this way the switch will turn on/off the LEDs as well as the sound board.

Let me tell you how hard this was to solder that wire to the switch. Even with a 10x Magnifier Loupe and a precision solder tip it took me awhile to make a solid connection.

Before installing everything in the base I had to make a post that the potato will sit on.  I was just going to use a brass tube but I was doing another project on the lathe so I just turned up a quick post out of the aluminum stock I was using and then glued it into the base.

The channel in the base is pretty small so wires have to be feed in through the top to fit through so for the wires I soldered to the board already I ran a wire down from the top, soldered them on, and then pulled them back through.

There are three pairs total…. two for power to the LEDs, two for the Speaker, and two for the Switch.

The board and battery just get mounted to the base with the double sided tape that came on them. The tape on the board is a bit hacked up from me looking for a place to add the wires for the LEDs.

Next the plug from the speaker was then de-soldered to lengthen the wires.

Here the plugs from the speaker and the switch are connected to the new wires that run up to the potato.

A small printed ring was then glued into the potato for a mount for the speaker to sit on.

Mounting the speaker inside the potato makes it more realistic (well as far as talking potato’s go) and the hollow cavity acts as an amplifier and makes everything sound much better. Without the processor part to cover the hole it’s almost way to loud but I can lower the volume of the sound module with settings.

Next it was time to wire up the LEDs. I used this cheap component tester to find the forward voltage of the random LED that I am using for the Chip so I can determine the resistor size I should use.

Without a resistor the LED is drawing a 6.2 mA at 3.7 volts which isn’t too bad but the battery for the sound module is only 110 mAh so using a resistor will limit the current making the battery and LED last longer.

Using an online LED Resistor Calculator along with a Programmable Resistor Board I was able to get the draw down to 3 mA using a 330 Ohm resistor.  The difference in brightness running the resistor is hardly noticeable but the draw is cut in half.   Now I need to do the same test to the Piranha LED.

I am also going to be using a 330 Ohm resistor for the Piranha LED and it will have a 5 mA draw and still be plenty bright. (At 3.7 volts with no resistor it draws 195 mA.)

For the wiring I connected the + positive wire from the sound board to the anode wire from coming LED in the chip. The – negative wire from the sound board is spliced into two 330 ohm resistors. One resistor then connects to the cathode wire from the Chip….

… the other resistor along with the positive wire connect to the piranha LED in the Processor. This completed the wiring for both LEDs.

I then used a little hot glue to secure the switch to the processor.

Next it was just a matter of soldering on the switch wires.

To finish up the base I installed some heat set inserts (not shown), attached the cover with a few 2-56 flat head screws, and added some rubber feet.

One last thing to do was glue on the chip connector. It’s only glued to the processor so I can still remove it if I need to although I may just eventually glue it all on.

Here is the completed PotatOS.

I am very happy with how everything came out although there are still some slight tweaks to make on the design.

This is how she sits on the Core Input Receptacle Base.

Close up detail of the Chip and wiring/clip.

The sprouts.

The on/off switch along with the UBS charging port is hidden in the rear of the base.

One main thing that I am going to change is to move the activation button from the processor to the base and add the other red LED to the processor.

Next it was on to the sound…  I used Audacity to edit and splice together somewhere around 140 sound files from the game to make an eight and half minute long skit where Chell turns GLaDOS into the PotatOS but then turns here back to keep from blowing up.  I don’t even want to tell you how long it took to find and edit of of these files.  A lot of the files are original but some were chopped, splice, and mixed together to make some slightly custom tracks.

Here is a video of the entire eight and a half minute sound track that I came up with.  It’s boring as far as the video goes (it’s just a spinning potato on a turn table) but the video was just meant to show off the sound track I put together.  This is recording from the actual potato playing… being a cheap sound module it’s a little scratchy on the recording but actually sounds pretty good in person.

Now it going to sit on my desk and anytime I think about how we are never going to get a Portal 3 I can press the button just to relive the glory days of gaming.

The End… Press the Button again.

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