This project is very similar to my other Instructable, Simple Hydraulic Machines. The difference here is that students are not shown any examples how to turn their simple hydraulic-powered hinge into something meaningful. Instead, students are taught only how to make a hinge that's actuated by a hydraulic system. The hydraulic hinge doesn't really do much on it's own, so students must decide for themselves what they want it to become.
Step 1: Materials
Step 2: Part 1 of the Hinge
- Make sure the cubes with holes are aligned as shown or else the skewer will not slide through
- Students should copy this part exactly as shown
Step 3: Part 2 of the Hinge + Connect
- Part 2 is simple - this is the piece that will be pushed by the output piston
- Thread a skewer through all three cubes with holes. Wrap tape around the ends to prevent the skewer from sliding out, then cut off of the excess.
- That's it! Note that the example on the cover image is attached to a base - this is not required. Not all hydraulic machines have the hinge assembly in an upright position.
Step 4: Make It Your Own!
Here are some things that I've seen students make. Some of these designs utilize a different orientation of the hinge piece:
- Cranes or other "up-down" machines
- Car with a hydraulic convertible roof
- House with hydraulic door
- Tank with hydraulic turret
- Car with a hammer/crusher on the front
- Robot that can bend over (power off) and stand up (power on)
- Adjustable gymnastics course for dolls
- Automatic cork shooter
Step 5: Assemble Hydraulic Systems
- Measure and cut about one foot of tubing
- Fill a syringe completely with water
- Fit the tubing securely over the tip of the syringe
- Press on the syringe to fill the tube with water, pushing out all the air
- Submerge the open end of the tubing and refill the syringe
- Fit the tubing securely over the tip of a completely empty syringe
- Glue a cube with holes on the end of one piston
If the control piston is pulled out of its cylinder, you can fix it by following these steps:
- Push all the water and air out of the output cylinder
- Remove the tubing that is connected to the output cylinder
- Reattach the control piston to its cylinder and refill it with water. If there is air, point the tip upwards and push the air out. Refill completely.
- Reattach the tubing to the output cylinder
Step 6: Attach the Hydraulics
The students can attach the hydraulics at any time after they finish the basic hinge.
The hydraulics can easily be attached in three steps:
- Cable tie the cube with holes that is on the end of the output piston to the underside of the moving hinge piece.
- Get a piece of tape ready. Remove all the water from the output piston and lower it so that the moving piece is at it's lowest desired position.
- Tape the cylinder in place. Use another one or two pieces of tape to secure the cylinder in place.
Step 7: Safety, Tips, and Troubleshooting
- Hydraulics are fun! Be sure to try this out at home, and maybe even make a contraption of your own.
- If a student is absent the first class, you may build the basic hinge for them as part of your prep.
- It's ok if students are not sure what to build at first. Give them 2-5 minutes to think about it, observe what other people are doing, and to play with your example or a unattached hydraulic system.
- Remember to warn your students to not pull too hard on the control piston!