2021 SECC Division A Project: Marble Machine


Item Description
Project Name Marble Machine
Age Requirement K to 5th grade students (elementary school students)
Project Code EC.A
Abstract Put your engineering skills to the test to see if you can build a machine—powered by nothing but gravity—that will automatically sort out two different sizes of plastic spheres. That might seem like a strange task, but have you ever used a coin sorter to separate pennies, nickels, dimes, and quarters? How about using a sifter in the kitchen to separate fine grains of flour or sugar from bigger lumps? Machines that can automatically sort objects or particles of different sizes are used in many applications; for example, in the mining industry to separate valuable gems and minerals from rocks and dirt.
Student’s Challenges Build a gravity-powered sorting machine that can separate small and large plastic spheres(Marbles)
Project Cost Registration fee:  $10 per team

Free registration for the SECC Competition teams with parents are CIE members or S&GA members.

Material cost:  Estimate (~$20)

Popsicle sticks (~$5): Amazon Link

16 oz paper or plastic cups (~$7): Link

6 mm & 10mm plastic spheres (~$7): Amazon Link

Scholarship Awards  Group 1 (K-2nd): 1st place: $50 2nd place: $30 3rd place: $20

Group 2 (3rd-5th): 1st place: $50  2nd place: $30 3rd place: $20

All Grade: 3 Creativity Awards, $20 each

Top 40% Winners will receive honorable mention awards and medals.

All contestants will receive E-certificates for participation.

The number of winners is subject to change based on the number of contestants.

Recognition Award recipients will be recognized at CIE’s website and eNewsletter, local news media, and showcased in CIE’s Annual Convention.
Individual or Team Contestant(s) can register as an individual or a team. Students are encouraged to form a team (max of 5 members) to participate in this tournament to learn teamwork and to share cost & responsibility.
Schedule  Saturday 2/06/2021 – Workshop#1 – Introducing Marble Machine Project 

Saturday 3/06/2021 – Competition Registration Deadline

Sunday 3/14/2021 – Workshop – Contestant-only Q&A session 

Tuesday 3/16/2021 – Submit an Engineering documentation page Deadline

Sunday 3/28/2021 – 2020 SECC Competition

What to Send before Competition Day
  • Send a 3 to 5 minutes video presenting your materials, marble machine, and your ideas online.
  • Send picture or digital form of your poster explaining your project
What to Bring on Competition Day
  • Your Sort Marble Machine
  • A poster/slides illustrating your engineering process, prepare a brief presentation or demonstration to show the Judges how your machine works.


Sorting machines come in all shapes and sizes, ranging from tiny toy coin sorters to huge industrial sifting machines used in food processing or mining. Regardless of what exactly they sort, they all have something in common: they automate a task that would be very difficult, or even impossible, for humans to do! It is not such a big deal to sort a few dollars’ worth of change or to use a hand sifter for a cup of flour. What if you worked at a bank and had to sort thousands of coins, or at a food processing factory dealing with thousands of pounds of flour? Then it would certainly help to have a machine do the work.

The same is true in the mining industry. Early miners would use a manual process, called panning to separate gold nuggets from dirt and sand in a pan. Modern industrial mines use a variety of automated processes to separate valuable gems and minerals from dirt and other rocks. Some sorting systems use complex electrical sensors, for example, to measure whether a metal is magnetic or how reflective it is, in order to sort them. Others use mechanical methods like screening, where particles fall through screens with different-sized holes. Particles with a smaller diameter fall down through the screens, while larger particles stay on top. Some systems use bursts of compressed air to blow away lighter materials, while materials with a higher density remain in place. Many times, these mechanical sorters are powered by motors, but simple systems are powered only by gravity.


In this project, your goal is to build a gravity-powered marble sorting machine that can sort large and small plastic spheres (representing rocks and gems, respectively), like the one shown in Figure A below. Keep in mind that the machine in Figure A is just an example of how you could approach the task. It is not necessarily the “best” method, and you might come up with your own design that is more creative or works better.

Figure A. An example of a gravity-powered marble machine. This machine is designed to separate spheres by diameter. Spheres are poured into the funnel at the top and then roll down the popsicle sticks. The smaller spheres fall through the gap between the popsicle sticks into the first cup, and the larger spheres continue rolling down to the second cup. 

Materials and Equipment

Rules, Procedure, and Scoring


Judging Criteria

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