Introduction: The Attack of the ROBOTIC MUTANT ALIEN!!!!!

About: I'm Mario Caicedo Langer (M.C. for short), a Colombian STEAM educator living in Azerbaijan, BSc in Naval Sciences and former Navy officer. I am a CAD and 3D Printing enthusiast and an artist specialized in jun…
Officially, I'm the first Colombian testing Sugru. It's a privilege and a good excuse for making something I always wanted: an evil mutant thing with robotic legs. Arachnid robotic legs. I love Krang from the "Teenage Mutant Ninja Turtles" and the Arachnotrons from "Doom II", and I dream with green viscous aliens riding robotic spiders, shooting plasma balls and trying to rule the world.

So, lets build one!!! We will hack a damaged toy car, assemble some junk pieces and add green silicone rubber, courtesy of Instructables and Sugru!

Step 1: Testing SUGRU.

What is the first step when you have a new toy? Well, to test it.

I had to know if SUGRU was that good, if it was a good choice for the project, how much SUGRU I could find in a sachet and how many sachets I could use. And find out if I am allergic to SUGRU (luckily, I'm not).

In the contest I found a great instructable that gave me some lights:

But, nothing like the empirical experience. So, in a non-related experiment, I repaired the broken band of my favorite watch. I used one black sachet. The superglue was only for keep togheter the pieces while Sugru cures (Before this experiment, I tried to repair the watchband with superglue only, and it was a bad idea).

The result? SUGRU IS AWESOME! And I think it's enviromental friendly because, if you make a good work, you don't have to thrown away your damaged plastic stuff. Just fix it and it will last for some more years. I made this experiment two weeks ago, and the watchband don't show rupture signs.

I has one suggestion: it will be good more Sugru colours. Yellow, pink and red would be great.

Well, let's go to the main project.

Step 2: Recipe for World Domination!!!!


1 electric toy car (you will need one who rolls straight forward)
2 3D glasses (we will need the glasses 4 legs)
1 AC adapter plastic box
6 iron angles
1 long plastic bar (I used one from a printer. You will need to cut it in two equal bars)
1 rectangular plastic piece
1 Big LED
1 Switch
1 AA 2 batteries holder
1 conic plastic piece
3 green Sugru sachets
cupper wire
1 deodorant cap
1 facial cream cap
2 vents
red and black wire
screws and bolts
Tin soldering


Dremel Rotary Tool
Wire cutters
Screwdriver kit
Soldering Iron

And don't forget the classic building rules:

1. If you don't have it, replace it!
2. Use protective equipment (dust mask and goggles)
3. Beware of drilled and soldered hot surfaces
4. Work in a good ventilated area.
5. Always have junk in stock
6. Enjoy!

Step 3: Hacking the Toy Car

You will need a simple electric toy car, with the simple action of going forward. The idea is to extract the gearbox (with the motor incorporated) and fit it into the AC adaptator box. I could use the toy's body, but it's made of very cheap plastic, and could get broken in the first fall.

Because of the fragile plastic cover of the gearbox, using screws to attach it to the adapter box wasn't the best idea. So, I have two options: superglue o black Sugru. Both are good enough, but each one has its advantages and disadvantages:
  • Superglue: it's instantaneus and strong enough. On the other hand, it leaves white dust, it's eye-irritating and if you are a beginner, you could leave scraps of cyanoacrylate in the project or worst, stick permanently the gears.
  • Sugru: when it cures is great, but you have to wait 24 hours before continuing with the project. And is a little bit bulky.
The choice is yours!!!!

Step 4: Crank Mechanism

You love walking robots but you don't have advanced knowledge in robotics? Then you will love this simple mechanism.

But remember something important: one wheel must have its angle directed to the front. The other wheel must have its angle directed to the back. This configuration allow the alternate movement. This is a video of how works the crank mechanism:

If you do it wrong (both angles directed to the same side), the result will be a little bit... disturbing.

Step 5: The Legs

You can use the four legs from the 3D glasses. Fix them to the angles, and when you have ready the electromechanic mechanism, cut its ends looking for the best performance.

Step 6: Electronics and Closing the Body

Relax! If you saw  the mechanics are simple, the electronics are even simpler. Just another parallel circuit with one led, one motor, one switch and the AA battery box. When you finish it, attach the facial cream plastic cap to the adaptator cover, and stick it to the spider body.

Step 7: The Invader!!!!!!!

Now is time for our little green monster. It's simple: just cover a plastic cap with enough Sugru and form it.


Step 8: The Thing With the Sugru Grip in the Legs...

I have a lot of comments about why I don't use Sugru in the legs tips for better grip. Well, when I was making the monster, I did the experiment with rubber from tires (you know, I have only a Sugru pack, so I needed to experiment with a cheaper substitute), but it didn't work, so I left my Mutant Sugru with its bare feet.

But you will never forgive me if I don't show proofs. So I put some Sugru on the legs, with two variants: Sugru in the four legs and Sugru only in the front legs (sillyzombie666's idea).

Four legs with Sugru

The video explains itself.

Why it's not working? Sugru can be an excelent rubber grip for walking robots, but not for this, because the front leg and the back leg are practically the same piece. If you look carefully the Intro videos, part of the normal movement includes a little slip when the front leg downs (and the back leg ups). With the rubber grips, we don't have the slip, and blocks the legs.

Front legs with Sugru

It's a little difficult to start, but has a better grip when gathers momentum.

The choice is yours!

Sugru Contest

Finalist in the
Sugru Contest