A crane is there to help lift large heavy objects, and both children and adults have always been fascinated with what a crane is capable of, so why not build one to play around with?

Here is an instruction on how to make a simple automatic and hydraulic crane, with a material list and step-by-step instructions.

Complete material list:

- 600 x 400 x 6 mm MDF board
- M4 25mm nut and bolt
- 2 x 10ml syringe
- Rubber tube (5mm diameter on the inside, 8mm on the outside)
- Cable ties
- Gearbox, including 3V motor (KNS7)
- 2 x Diode, standard, 1A, 400V
- Switch: single pole, double throw with center off (SPDT ON-OFF-ON)
- 0.2 electrical wire
- An old phone charger (5V)

Tools:

- Lasercutter
- Glue gun
- Soldering iron

Step 1: Step 1: Lasercutting

Material:
- 600 x 400 x 6 mm MDF board

Tools:
- Lasercutter

In the picture you can see the template we used to build the crane.

We worked with specific tolerances for the lasercutter we used, so remember to adjust accordingly to your lasercutter.

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Step 2: Step 2: Building the Crane

Materials:
- M4 25mm nut and bolt
- Parts 1-6

Start with parts 1-3 to assemble the bottom of the crane. You might need a hammer to get them into place. Put part 1 and 2 into the outer slits of part 3.

Hammer parts 4 and 5 into the middle slits of part 3. Make sure that the cut-out parts of 4 and 5 are the same direction as the feet.

Use the bolt to secure part 6 between part 4 and 5. It should be able to rotate, so not too tight.

There you have your crane!

Step 3: Step 3: Hydraulic System

Materials:

- 2 x 10ml syringe
- Rubber tube (5mm diameter on the inside, 8mm on the outside)
- Cable ties

Tools:
- Glue gun

Secure one of the syringes with a cable tie on the inside of part 4 and 5, so that part 6 is resting on it. The cable tie should not be too tight, as the syringe should be allowed to move a bit.

Put the tube through part 4 and 5, so it comes out the back, as seen on the picture.

Use a glue gun to fasten the 2 syringes to the tube.

Fill with water.

Step 4: Step 4: Pump Box

Materials:
- Parts 7-14

Tools:
- Glue gun

Start with assembling parts 11-13. Glue the sides together using a glue gun.

Build parts 7-10 around the previously assembled part. Part 10 has to go in the fronts of part 7 and 8, marked with a dot.

Part 14 will be used in the next step.

Step 5: Step 5: Gearbox

Materials:
- Gearbox, including 3V motor (KNS7)
- Part 14
- Pumpbox

Tools:
- Glue gun

Start of with building the gearbox with the instructions from the kit. Use the gear settings 1:288. But don't add the output shaft, as that has to go through the pump box as well.

Turn the pump box upside down and put the output shaft through the hole on one side, then add part 14, then let the shaft come out the hole on the other side.

Glue part 14 to the output shaft, in the correct position.

Then assemble the rest of the gear box.

Step 6: Step 6: Motor

Materials:
- 2 x Diode, standard, 1A, 400V
- Switch: single pole, double throw with center off (SPDT ON-OFF-ON)
- 0.2 electrical wire
- An old phone charger (5V)

Tools:
- Soldering iron

Use the soldering iron to add 2 pieces of wire from the gear box to the switch.

Solder the 2 diodes together.

Solder a piece of wire to one diode, and the other end of the wire to the switch.

Cut off the plug off the charger, and strip the wires.

Solder the wires from the charger to the diode and the switch.

The diagram illustrates how the switch is connected.