Hovercraft Challenge

Overview

Rippl3D’s Hovercraft Challenge enables players to 3D print thrusters to add a new level of fun to the balloon & CD Hovercraft experiment. Players design thrusters that control where the supply air (balloon) is directed and how fast it is released. These simple parameters offer a surprising number of  teaching opportunities. The challenge can be played on any smooth surface (tables, hallways, gym floors). This challenge is fast paced and always good for some laughs.

Relevant STEM Principles

Forces, thrust, air pressure, lift, and stability

Outcomes

Using a stopwatch, record the time it takes the hovercraft to traverse a given distance.

Challenge Components

The hovercraft is build from the following components

  1. BalloonHC Parts Defined
  2. CD
  3. 3D Printed Parts
    1. Balloon Support
    2. Balloon End
    3. CD Base (glue CD base part to CD with 2 part epoxy)

In the Design Challenge the Control Cylinder is designed and built uniquely for each attempt! Each player will design these solutions in the web app.

In the Type Challenge, ten different types of Control Cylinders are pre-printed and the participants pick the ones they think will perform the best.

 

Design Parameters

The Control Cylinder has 4 parameters that can be adjusted to change performance.

  1. Base Port diameter (Lift/Hover Control)HC Control Cylinder Parameters
  2. Width of Triangle (Thrust Port)
  3. Number of Triangles (Stability & Thrust Control)
  4. Angle of Triangles (Stability Control)

Design Considerations

  • Hover/Lift
    • Increasing Base Port dia. increases lift
    • Increasing lift reduces how much thrust can be generated
  • Thrust
    • Increasing Triangle Width and No. of Triangles will increase thrust
    • Increasing thrust reduces amount of lift available
    • Minimizing  rotation angles will maximize thrust
  • Stability
    • A stable Hovercraft will travel down a path with less influence from outside forces
    • More triangles increase stability
    • Increasing rotation angle can increase stability

HC Forces Diagram

Equipment & Setup Ideas

Balloons &  Pump

All parts have been designed around the use of 9 in latex balloons.

Although lungs will work to blow them up, they also come with moisture and colds…

We suggest a balloon pump! This allow balloons to be reused and keeps moisture out that can increase weight. Moisture will impact performance and is unsanitary at public events. We have designed an adaptor that can be used to make it easier to engage the balloon end tube for filling, get the STL in resource section below.

TRICK: Fill balloon with pump and then give the balloon a couple of twists to close it off. This makes it much easier to assemble the hovercraft parts and get it positioned for launch! When ready carefully untwist the balloon and off you go!

Measurement Tool

To get the diameter and height of the balloon you will need calipers. In the resource section below there is an STL file that uses a common rulers and yard stick to make a caliper.

Track

You will need a smooth and level area roughly 8 feet long and 2 ft wide. Tables and the floor have been successfully used. It helps to have walls on each side to keep hovercraft on the track. But, if you want to increase the difficulty of the challenge, make a rule that any out-of-bounds doesn’t count. If you are expecting large crowds, it is also helpful to shield the track from traffic and breezes that can have a huge impact on the direction the hovercraft will travel (note that the balloon is a big sail).

STEP 1: Pick a Challenge Type

Type Challenge

This Challenge uses 10 predefined Control Cylinder configurations (see resources below)

  • Print parts in advance to accelerate how many participants can play
  • Participants select from 10 Control Cylinder configurations
How To Play
  1. Provide participants a Job Sheet to track their design decisions and results
  2. Login to Rippl3D Challenge site
    1. Select the Competition for your event
    2. Select the Control Cylinder Configuration you want to test
    3. Enter the balloon diameter
    4. Save the design and record the Job Number on a Job Sheet
  3. Assemble parts
  4. Test the Hovercraft and record your score on the Job Sheet
  5. The Competition Coordinator will enter the score for your job number
  6. Review the results and try again to improve your score

Design Challenge

The Design Challenge plays the same as the  Type Challenge except that the Control Cylinders are designed and built custom. Players use the design tables to configure unique designs and then download the STL file for printing.

How To Play
  1. Provide participants a Job Sheet to track their design decisions and results
  2. Login to Rippl3D Challenge site
    1. Select the Competition for your event
    2. Enter the parameters you think will provide the best performance
      1. Base Port diameter (Lift/Hover Control)
      2. Width of Triangle (Thrust Port)
      3. Number of Triangles (Stability & Thrust Control)
      4. Angle between Triangles (Stability Control)
      5. Enter Balloon Diameter (Propulsion)
    3. Save the design and record the Job Number on a Job Sheet
      1. The job sheet will provide a good way to track your 3D printed part
    4. Download the STL file
  3. 3D print STL file
  4. Assemble parts
  5. Inflate balloon to selected diameter
  6. Test the Hovercraft and record your score on the Job Sheet
  7. The Competition Coordinator will enter the score for your job number
  8. Review the results and try again to improve your score

Unlimited Challenge

After learning what provides the best results, use your knowledge to design your own hovercraft and further optimize it’s performance. See just how fast and consistent you can get your design to perform.

Resources

Job Sheet

Job sheets are very useful for keeping track of design decisions and test results.

 Job Sheet Hovercraft Type Challenge

Job Sheet Hovercraft Design Challenge

Hovercraft Part STLs

Helpful Hovercraft Part STLs

Caliper_Hub

The Caliper Hub is designed for the following items specifically, but you could custom design one for any combination of rulers and yard sticks!

$0.25 School Smart Scale Ruler made of selected wood features a multiple-coat, clear lacquer finish. 12 in Ruler with non-metal edges is scaled in 1/8 in. Ruler has a thickness of 5/32 in and width of 7/8 in.

$2.00 School Smart Yard Stick is made of hardwood with a multiple-coat, clear lacquer finish. It is scaled in centimeters and also divided in both millimeters and eighth inches. Storing is made easy with a hole for hanging. The stick measures 1 meter x 1 inch x 1/4 inch.

Pump Attachment

 

Use this to simplify how the hand pump engages the balloon section for inflating the balloons.

Hovercraft Parts List

Competition Prep Sheet

Coming soon