Dr. Sixtopus: a PVC Exoskeleton for Kids

Exoskeletons are absolutely amazing, complex, and quite expensive. I would love to drive one of those in the movies, like Aliens or Elysium.

Possibly that is out of my reach, but I can make something cheaper, quickier and fun for my kids.

Supplies

You will need a lot of pieces of PVC pipe.

You will find all different PVC pipes in your DIY store. you can get pipes with thick walls, used for water under pressure, and another ones with thin walls, for drain lines, sewage.... Use the first ones.

In my country (Spain) these are sold in dark grey, in strips of 2 or 3 meters. If you can buy white ones, much better!

More supplies required:

20mm elbows (12)
20mm t-joints (4)
25mm elbows (8)
25mm t-joints (6)
PVC glue
Twine
Screws (I used M8)
Locking nuts
Kid :-)

Optional:

Rubber caps
Spray paint and protection mask

Tools:

Measuring tape
Pencil
Saw, and/or pipe cutting shears
Heat gun (you could use an oven, alternatively) and gloves
Sand paper
Screwdriver
Pliers or wrench for the nuts
Cutter
Spring, to avoid pipe colapsing (use sand alternatively)

Step 1: Cutting a Bunch of Pipes

You will need a lot of small sections of pipe, in different sizes.

I have been prototyping this exoskeleton with a little help of my kids, but you possibly want to change some measures to adapt it to yours. You can make it for adults as well. It will be a lot of fun as a party challenge!

First at all, a few advices:

Remember that arms and harness are build with 20mm pipes, and armrests with 25mm ones.

Do not glue anything until you have all the pieces assembled and tested.

Use PVC glue and spray paint in a well ventilated place.

Well, take your measuring tape and your shears and start cutting following the plan. With the shears you will work really fast, but a saw will also do the job. I like the japanese style saws as they make really precise cuts.

Use some sand paper to remove the burr of the cuts.

Step 2: The Mechanical Claws

Let's start with the claws.

(I recommend to wear gloves it your at not used to this tools)

Grab one of the short 10 cm sections of 20mm pipe and heat it with the heat gun. Do not focus the gun in one place or you will burn out the pipe. You can also use hair dryer, or an oven

PVC smoke is toxic. Do it outdoors.

When the pipe starts to soften, flatten it with a bank clamp, or just make a sandwich with a couple of tiles, bricks, or pieces of wood.

Let the PVC cold down before removing the piece of pipe, or it will try to get back to its original shape.

Drill holes (according with your screws, mine are 8mm wide) at 15mm of both tips. Screws must move tight but freely in and out of the holes.

Repeat it with the other three 10 cm sections.

Now take one of the 10 cm pieces of 20 mm, and draw a mark at 10 cm. Heat only that section and flatten it.

Repeat it with the other three 20 cm sections.

Drill holes at 15mm and 85mm of the flat tip. You can use one of the 10 cm pieces as pattern.

Use one of the longer screws to join the 18 cms pieces, and short ones for the 10 cms pieces, as shown in the photo. I recommend one flat head screw for the bottom hole.

Add a couple of elbows and two short pieces of PVC to finish the fingers.

Step 3: The Long Arms

A claw is nice, but a claw at the end of a long arm is a lot more fun (Octopus said).

PVC pipe is not particularly rigid. You could make a two meters arm with this mechanism, but it will probably bend badly.

And, even wearing the full exoskeleton, a weight at the end of a long lever would be hard to lift.

So, we will cut the arms (20 mm pipe) to 80 cm.

Drill a hole at 15 mm from the end and attach the claw.

Extra tip: If you make it tight enought you will not need a nut to hold the screw in place.

Make another hole, at 25 cms from the same tip but tilt the drill to make it angled.

Next, make the handle with a T-joint, a couple of elbows, and short sections of pipe. Follow the measures in the plan.

Cut 1 meter of twine, tie it to the lower screw of the claw (the one with the flat head), pass it through the sloped hole and take it out the t-joint of the handle.

Another Extra tip: if your string is very light and it does not want to go thru the pipe, tie one end to a small nail.

Finally, link the two screws in the midle with a rubber band, tie the end of the twine to a ring of PVC pipe and you have a functional arm!

Last minute tip: adjust the knot of the handle to tense the string properly.

Step 4: The Harness

This is -perhaps- the trickiest step.

You need to bend a couple of sections of 20 mm pipe to make the shoulders of the exoskeleton. Dimensions depend of the body. I recommend to have your kid close around and test it (as soon as the pipe cold down). For my loved Guiller, I used a couple of pieces of 50 mm.

I put a spring into the pipe to avoid it to colapse. If you do not have one, try to fill the pipe with sand, close temporary both ends (with adhesive tape, for example) and then use the head gun to bend it.

You should end with a curved shape like the one shown in the photo.

Put the shoulders pieces together with four t-joints and a couple of horizontal sections of pipe.

Now, change to 25 mm pipe to make the armrests. Follow the plan to make four "L" shapes.

Add a t-joint to the short end, and an elbow to the long one of each "L". Connect two 'L"s with a vertical piece of pipe between the t-joints. This allows the armrest to rotate freely.

To connect the two elbows, you will need two short pieces (6 cms) of pipe with a t-joint in the middle. Make a big hole in this t-joint to pass the arm through it.

Finally, slide the two armrests over the lower endings of the backpack. Add another horizontal section of 20 mm pipe and a couple of elbows to close the end of the backpack.

The armrest should move back and forth freely. This will allow your kid to give hugs or clap with the mechanical hands :-D

Step 5: Assembly and Final Touches

If you want to paint your exoskeleton and give it an awesome look, it is better to do it before glueing the pieces.

This way you can use different colors without wasting loads of masking tape.

I decided to give it a look resembling the famous P-5000 power loader from Aliens, combining bright yellow spray and the original dark gray.

Extra tip: do not paint the endings you are going to glue.

Once the paint is dry, it is time to glue (almost) everything!

Final tip: if you want to reuse the arms alone, do not glue the handles. Instead, add a small screw to the joint. With these detachable arms, the exoskeleton is more portable and easy to store as well.

True Final tip: If you make the bottom piece of the backpack removable, you can turn the backpack, and place the armrests in front of your body. This way kids and adults can share this awesome exoskeleton!