Hydraulic Robot Made of Cardboard and Scotch Duct Tape.




[ please give me a vote for the contest if you like the instructable, thanks]

I always wanted to do this project but in all the guides i always found that you need some kind of wood cutting skills and/or tools. So … I decided to make a simple hydraulic robot with cardboard, reinforce and hold by duct tape that anyone can do.
Duct tape not only is strong but also looks pretty cool; it gives the robot a cool metal like look and it holds everything together really good.

Step 1: What You Are Going to Need!

- Cardboard box (the harder the better, I used a pizza box but you can used any type because we are going to reinforced with the duct tape)
- Scotch Duct tape (I like the silver because the metal like look)
- 3 machine screws 3 inches in size with nuts
- 2 machine screws 1 ¼ inches in size with nuts
- A flat and square piece is wood ideally 12 inches by 12 inches for the base to attach the robot
- 8 syringes (you can get them at any pharmacy without prescription just say you need the type that is use for cough medicine, you can’t put a needle on those. I got mines at CVS and Walgreens for free)
- 6 feet of clear tubing ¼ “x .170” (got mine at home depot for $3)
- Water
- Scissor
- Ruler
- Pen
- Drill

Step 2: Draw the Template

Now draw the template on the cardboard, these are the measures that I used but you can change them to make a smaller or bigger robot.
From the template cut out:
2 x A piece
2 X B piece
2 x C piece
2 x D piece
1 x E piece
These are the main parts of the body and the rest of the parts are going to be made as you go because they depend on the thickness of your cardboard and how many layers of duct tape you use. Because I used thick pizza box I only needed one layer.

Step 3: Reinforce You Parts

Now that you have all you parts cut out you have to reinforce them. First cover one side of a piece with duct tape and the cut the extra tape, the cover the other side and cut the extra tape.
Repeat this for all the parts, if your cardboard is not strong enough repeat this step putting more layers of tape until you are satisfied with your result.

Step 4: Start Building

Now the best part, when you see that your robot starts taking shape.
The next piece you have to make is a cube that is going to hold together the bottom of the 2 “A” pieces
For my robot I used a cube that is 3 inches wide by 1 inch sides (cube= 4 sides)
After you cut and fold the cube reinforce it with tape.

Step 5: Continue Building

The reinforce cube needs to be attached to the bottom of the “A” piece (the bottom is the longer part 3”)
First attach it to one piece and then the other.
Put your piece in the floor to make sure the cube is level before taping.
The technique i use for taping i call it L taping, look at the picture so you can understand better.
Next attach the "A+CUBE+A" piece  to the 6" circle base using L taping (use as much tape as you think is necessary to get a strong hold )

Step 6: Make Your Next Cube and Holder for the First Syringe

Hold your two “B” pieces on the inside of the “A+CUBE+A” piece and measure the space between them, that is how wide your cube needs to be.
Now make your cube with your new size following step 4
( in my case my new cube is 2 1/2" wide)
keep the 1 inch measure for the sides of the cube.
After making your cube attach it to the “B” piece leaving 1 inch space from the end.
Next depending on the thickness of your cardboard make 2 or more squares as wide as your first cube (in my case 3 inches) by 1 inch long and tape them together , this will be taped to the middle of the “A+CUBE+A” piece to hold the syringe.
Place the square vertical and give it just a little of an angle.

Step 7: Build Next Part and Next Cube

Repeat the beginning of step 6 but with  the "C" pieces. Hold you “C” pieces on the inside of the of the “B+CUBE+B” piece and measure the space between them, that is how wide your cube needs to be (in my case 2 inches wide) by 1 inch long for the sides.
Reinforce the cube and the attach it to the corner of the "C" pieces.

Step 8: Make the Holder for the Claw and the Claw

Now you have to make the holder for the claw that goes between the “C+CUBE+C” piece.
The holder is a “rectangular cube” that is 4 inches long and the sides are 2 inches by ½ inch.
follow the same steps in step 4 and the attach to the front of the "C+CUBE+C" piece flush with the front.
Now make the claw, the "D" piece. depending on the thickness of your cardboard you need to put as many layers of cardboard and tape as you want until you get a strong claw (in my case 2 layers of cardboard and one of tape)
Make hole in both parts of the claw large enough for your 1 1/4" screw
Now make a hole in the front corner of the claw holder in the "C+CUBE+C" piece
Put you screws and attach the claw parts.
At this point you should be half way there, hold the parts on their place and drill you have to drill in the joints of the robot  across the inside of the cubes and place you screws.

Step 9: Attach to Base and Make Hydraulic System 1st Syringe

Now attach the robot to the base.
Drill in the middle of the cube at the bottom of the "A+CUBE+A" piece and on the wood for the base and put your 3" screw.
Now to start with the Hydraulic system.
Attach you first syringe to you holder on the "A+CUBE+A" piece (just like the picture)
Now cut two pieces as wide as your second cube by 1/2 inch tape them together and attach this to the 1 inch space you left in the "B+CUBE+B" piece (just like the picture)
then put a pin in that new piece and tape around it then tight a piece of rope to the pin and from there to the syringe tight and cut, make sure the arm is down and the syringe is all the way out to get the right length of your rope (refer to picture for better understanding)

Step 10: Second Syringe

For the second syringe you need to make a holder in the top part of the "C+CUBE+C" piece. 
Use the same procedure as step 9, make sure the arm is down and the syringe out to get the right length for the rope. 
This is completely adjustable depending on how high or how low you want your arm to move, play around with the length of the rope to find out what works best for your robot 

Step 11: Syringe for the Claw

The syringe for the claw is going to be directly attached to the claw with duct tape, make sure the duct tape is not too tight so the claw can move freely.

Step 12: Syringe to Turn the Arm

At the base of the robot attach a pin and the a syringe about 3 inches from the pin
Attach a wire from the pin to the syringe when the syringe moves makes the arm rotate left or right.
Now tape to the wood base 3 syringes next to each other, each of these are to be connected to the syringes in the arm.

Step 13: Run the Tubing to All Syringes

Run the tubing to all the syringes and the fill with water and enjoy.
Watch the video to see the project done.


Second Prize in the
Duct Tape Tough Contest

Second Prize in the
Kinetic Sculpture Design Contest

Participated in the
Humana Health Challenge

Participated in the
Epilog Challenge

Participated in the
Joby Transform It! Challenge

3 People Made This Project!


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151 Discussions


2 years ago

Its very cool and very good for Exhibition everyone should make it.
best of luck for making.
I am making this tooooo.


2 years ago

i made the hydraulic arm at home for my science project


3 years ago

awesome...love this....just when i was looking for a good project...thnx for posting this...

Kyle Samlal

3 years ago

Very excellent project 11/10


3 years ago

Me and my dad are doing this but we are stuck on step the where you put on the cube for C+CUBE+C part. any help? plz


3 years ago

Cool. I'll build it at home.


3 years ago

will this affect the size of screws needed


3 years ago

guys i am going to substitute tt about he cardboard with wood so it will be able to lift about 1.75 kgs


3 years ago

Nice project

Just wanted to ask what volume of syringes were used(other than 5ml;i have seen the photo )

And what can be done if duct tape is not available?

1 reply

Reply 3 years ago

I actually make these with my tech ed class at school.. I use 5's, 10's, and 20's. Uncertain as to what to do in regards to having no duct tape available.. Perhaps popsicle sticks and hot glue, with mini bolts and nuts to hold moving parts together?


Reply 3 years ago

is it binding on anything? You have them filled with water, right? Ensure they are not rubbing on anything. Also, are you using both syringes of the same size? If you are pulling on a smaller diameter syringe to move a bigger syringe, you will have to pull much harder depending on differences in diameter.


3 years ago

when i pull out in the syringe, the other syringe doesn't push in. Can you please help me?


3 years ago on Step 8

what date do you do this? is that im doing this scienproject?


4 years ago on Introduction

this is the best one among all i have explored on this site

you are simply awesome like it


4 years ago

Does anyone know whether 1 tbsp syringes work or if 2 tbsp. (10ml) are needed?