Welcome to Robot Dialogs. This is a place where I will record my progress, mistakes, errors, failures, lessons learned and hopefully occasional success in my designs and implementations of robots and other technical endeavors. I will try to make it as educational, informative and entertaining as I can...

Saturday, August 20, 2011

Potato GLaDOS (from Portal 2)

I haven't done a proper project in a long while, and this past weekend it finally got to me. So I decided to try my hand making a prop/replica of the tuberous AI from Portal 2. I give you Potato GLaDOS:

Most of it was sculpted from Sculpey and painted with acrylics. The audio comes from an old mp3 player I had lying around. The electronics consist of a LM386 audio amplifier, speaker, LEDs and a simple circuit to pulse the LEDs with the audio. 

Here's a long winded explanation breakdown of how it was made. There's a boat-load of build pictures out on Flickr. The audio was pulled from here and spliced together in Audacity.
Please support the developers and artists of these amazing games: Purchase Portal 2!

And remember: "This. Sentence. Is. FALSE".

Potato GLaDOS Build Notes

I started with pictures and models from the tubes. The image below is a particularly good example showing both sides.
Model Reconstructed by ~Zareste

I went to the grocery store and found some models that I could hire for pennies an hour. I used Sculpey for the potato and GLaDOS, but I didn't want to bake it for four million years, and I needed a hollow inside for all the electronics so I made a potato-ish shape with aluminum foil. Keeping the outer layer of aluminum foil as smooth as possible will help when the foil is pulled out of the baked Sculpey.


As you might expect potatoes are particularly easy to sculpt. Imperfections are the main feature...trying to keep fingerprints and fingernail marks out of the clay is the most difficult part of it. I don't have a picture, but the large hole (through which electronics are inserted) was cut out of the clay before it was baked. Scupley isn't too brittle after baking, but I didn't want to take a chance cutting a huge hole in it... I also put the nails in before baking so that the puncture spots would look more realistic.

After sculpting the parts and a few extra pieces for drop and paint tests it all goes in the oven at 275° F for 15 minutes per 1/4 inch. These parts took a little over 30 minutes. The clay wont be hard right when it's pulled out of the oven, but once it's cooled it will be pretty hard.


After baking the parts were sanded smooth and washed with a damp cloth before painting. Sharp edges can be removed by sanding or with a knife.The aluminum foil pulled out from the inside of the potato pretty easily, again the smooth outer layer of foil really helped.




For the smaller parts (the over-sized chip and the colored bangles on the alligator clip cables) Sculpey was used as well. Rather than fire up the oven again I just pointed a heat gun at them for 3-4 minutes (the temperature was 275° F-ish again).

To make the 'bangles'/chokes for the alligator clip wires I wrapped Sculpey around a nail, flattened two sides with hobby knife and then cut the other two sides to make it as square as possible. These pieces were baked (with a heat gun) and then scored at the right lengths. If the nails are smooth enough the cooled clay will slide right off.


I painted everything with acrylic paint. Sorry no in progress shots of that, I wouldn't be the right person to explain painting :). The Sculpey is very drill-able so after painting I drilled all the holes for the black wires and red LEDs.


Next (well actually first) came bread-boarding of the audio/LED circuit. Good luck figuring that out from the picture :). Circuit diagram below.

I sort of combined the content of these instructables to achieve this circuit:
Blinking LEDs to Music (The IRL2703 is WAY overkill for this application.)
Simple LM386 Audio Amplifier
I found some round prototyping boards at RadioShack (actually all of the electronics you can pick up there). The LED stuff went on one round board and the control/amplifier on a smaller board. GLaDOS's 'eye' is simply a clear marble. It creates a pretty good lens effect. In the middle of the yellow LEDs I put a small piece of aluminum foil (not shown) to reflect light up through the marble.


The red LEDs were put into their respective holes and the small wire used to connect them to the battery was super-glued to GLaDOS/the chip.


The speaker was sandwiched in between the control and LED boards and copious amounts of hot glue was applied.


The hotglue around the LEDs got some black paint layers to block out unwanted light.


The small wires to the red LEDs were also painted to match...sorta.


Apply power, cross fingers....
It works!


The alligator clip wires were super-glued into holes on GLaDOS. The yellow one in the model (first picture) has some extra bits near to GLaDOS.  Those extra bits I made with heat-shrink wire wrap and another peice of Sculpey painted black. The six black wires around the circumference are all that is used to hold GLaDOS onto the potato. I think they're supposed to be staples, but whatever.


Completed GLaDOS portion.


The yellow wires that wrap around the potato were hot glued (on the inside) into place. The audio comes from an old mp3 player stuffed inside the potato.


Complete Potato GLaDOS. (Off.)


Complete Potato GLaDOS. (On.)


Video goodness:
The audio was pulled from here and spliced together in Audacity.
Please support the developers and artists of these amazing games: Purchase Portal 2!


Questions are welcome, but the Cake is still a lie.