After my girlfriend successfully completed Portal 1, both of us were craving to have one of those cute, little turrets on our desks. We came up with Kinder Eggs (http://en.wikipedia.org/wiki/Kinder_Surprise ) because they roughly fit the ellipsoid shape and are very stable. Unfortunately the turret cannot shoot but instead of that it's equipped with an LED that lights up if you pinch the two antennas on top.

Read on and discover how you can build your own turret for your desk. Feel free to comment if you have any questions :)

Edit: I've noticed there is another rather similar instructable around. We did not steal or copy anyone's ideas, we came up with these turrets on our own.

Step 1: What Materials/tools Do You Need?

The required materials are cheap and mostly easy to obtain. The Kinder Egg itself might be an exception as they're either not available due to your home country (they're banned in the US) or due to the high temperatures in certain months (they're usually not sold in summer months). You may buy a few hundred empty Kinder eggs from ebay if you're desperate.

Materials (length specifications include enough buffer):
- an empty Kinder Egg of the newer series, i.e. not the ones that consist of two parts (see images for reference)
- a 28cm and a 16cm part of black, solid copper wire with a diameter of approx. 2mm (incl. coating)
- one spoke reflector
- a 5mm LED in your favourite colour
- an LED holder (ours came from an indicator LED of an old PC – take a look at the images)
- a CR2032 coin cell battery holder (from the mainboard of the PC - use duct tape if you can't get hold of one)
- two 5cm parts of thin, solid copper wire to be used as antennas and as the switch
- acrylic colours

Tools (required):
- skilled and/or thin fingers!
- a pair of combination pliers
- a paint brush
- a soldering gun

Tools (recommended):
- a wire stripper
- a round file
- a small nail

Step 2: Make Holes

Start off by preparing the holes for the legs, the LED and the antennas. We carefully pushed the nail through the desired spots and widened the holes a bit with the round file. Do not widen the two tiny antenna holes, as the core of the two small wires should be the only thing that fits through.

Step 3: They Come in Hundreds of Designer Colours...

Time to paint your turret – you decide whether the appearance will be forest, desert, table or just plain white (our colour reads “Titanium White”).
After two layers of colour the yellow plastic didn't shine through anymore, but you might want to put a third layer on top.
While the colour dries you can already take care of the soldering part in the next step.

Step 4: Soldering

Solder the LED holder, the two small wires and the battery holder (if you have one) as depicted above. If the cable coming from the LED holder is rather stiff and not a stranded wire, you may save the second small wire.
Test whether your LED is plugged in the right way.

Step 5: Creating the Legs

This is roughly what your turret will look like after the colour has dried. Now it's time for the bending part – grab the two black wires and bend them as follows:
- bend one end of the shorter wire to a tight, little spiral followed by a 180° turn in the opposite direction (we suggest taking a clarifying look at the images)
- bend the longer wire in half while creating a loop with your thumb (images, again :D)

The loop will keep the whole leg structure in place because it adds pressure from above.

We recommend widening the holes for the wires now, if you haven't done that before.
Push the non-spirraled side of the hind leg from the inside of the turret through the corresponding hole to the outside. Secure the spiral in the bottom centre of the turret, then push both forelegs through their holes (again, from the inside to the outside). Estimate how much of the cable you can push out to leave the loop at the top of the egg if it's closed.
Sculpt the wires in a way that they match the shape of the egg and press them hard to the bottom so they keep the hind leg in place.
Your turret should now resemble ours on the third image.

Do your best in sculpting the outside legs (google for reference images) then head for shortening the wires. You will most likely discover now why it's so easy to knock them over in the game. ;)

Step 6: Putting It All Together

Put the LED to its designated place after adding a battery to your battery holder. Move the two small wires through their holes, then fumble it all into the egg.
The only thing left to do is to pinch off three 1cm parts of spoke reflector with the pliers. Clip them onto the legs (or paint them before, if necessary).

Step 7: There You Are :)

The turret should now be finished and if everything went fine, the LED lights up if you pinch the antennas. ...Now get a mass production going and send a turret to each of your Portal-addicted friends as a Christmas gift ;)

Remember to comment if you have annotations or problems with this project.

If you're motivated, you may try to realise one (or more?) of the following ideas:
Try adding a small headphone loudspeaker to the turret. This would even work without ugly cables coming out of the turret – because you can misuse the legs as the two contacts required for the speaker. :) Build some sort of “dock” with two separated metal surfaces, connect a 3,5mm audio jack to them, strip the tip of the legs a bit and solder the speaker to the legs inside.
You could also just outsource the battery with this dock and have your turret's LED light up as soon as it gets electricity on its legs – that would definitely simplify changing the battery.
Or try making the LED music reactive: Just combine the turret, the dock idea from above and a music reactive LED instructable.

Post a comment if you've done so, we're happy to see your creations. :)