Creating a Force Plate Using Items You Might Already Have At Home

Category : High School, Middle School, Physics · No Comments · by November 19, 2020

Making a Homemade Force Plate

Staying home during COVID means teachers and students have to get creative.  Things that you would normally have at school you might not have at home and vice versa.  A few days ago I decided to see if I could make a homemade “force plate” that could accurately measure impact forces.  My smartphone has a high speed camera.  I just needed something that was sensitive enough that it could measure tiny forces happening over very short periods of time.

My solution is shown above.  To build it you will need:

  1. a laser
  2. a wooden stick
  3. a piece of paper and scissors
  4. tape
  5. a ruler
  6. a stack of cards
  7. (optional) a small kitchen scale to calibrate your force plate

Assemble your force plate as shown above.  Adjust the height of the stick such that the laser beam hits the middle of it.

Using the Homemade Force Plate

To measure static forces, press on the plate.  As you press the laser beam will move across the stick.  You can use a ruler and some known weights to calibrate your stick.

Measuring Impact

To measure impact, download a suitable video analysis app to your smartphone.  For iPhones and iPads the “Technique” app by HUDL works well.  I used Technique and a homemade force plate to create the latest Video Motion Analysis activity, “Measuring The Force Of Impact Over Time“.  In the activity students learn how padding minimizes the force of impact.

Feel free to share and comment below!

-Chris


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