Demonstrating the Right Hand Rule in Magnetism

Hi!

I am a Physics teacher who works at the Schwartz/Reisman Science Education Center, and as part of my work here I teamed up with Dr. Shani Guttman (Physics teacher who also took the photos) and Hanoch Bar-Nitzan (Industrial Designer) to build a demonstration of the Right Hand Rule which helps determine the directions of the magnetic forces acting on a current-carrying wire in a magnetic field.

Oddly enough, we used magnets in order to explain a magnetic phenomenon.

The tools we used:

• 3D printer
• Hammer
• File
• Philips head screwdriver
• Scrap wood
• Craft knife
• Vinyl plotter (optional)

Materials:

• 3D printer PLA filament (red and green)

• Four 20mm*20mm square profile tubes - 20 cm long 2mm thickness

• Four 3.5*13/13 wood screws

• Four Neodymium magnets 2 cm in diameter 2.7 mm thick

• Flexible magnetic strip
• Blue and White vinyl sheets

Step 1: Building the Frame

Quick note - for the prototype I cut up discarded IKEA furniture, but for future models I bought the metal pipes.

For the design, I consulted Hanoch Bar-Nitzan and he designed the L-connectors for the frames.

I 3D printed four copies of the STL file, but the supports were in the way so I filed them in order to have a snug fit.

I then hammer the L-connectors using the scrap wood as shown, so they wouldn't break.

(to be fair, I did break one or two)

I attached the L-connectors to opposing sides in order to avoid deforming the right angles during the build.

Step 2: Current Vectors

For representing the current vectors, I cut eight strips of flexible magnet tape and using a vinyl plotter cut arrows with the symbol I.

If you do not have access to vinyl cutter, you can just cut the magnetic strip with a craft knife and stick the vinyl sticker.

You will need eight arrows in order to visualize the current direction on both sides of the frame.

Step 3: Force Vectors

The last bit is fairly easy.

3D print four copies pf the STL file.

The arrows have a circular indent in which the neodymium magnets fit snug.

Then you screw the magnets in place, the STL file has a small hole for the wood screws to burrow in.

Step 4: Putting It All Together and Teaching

Now you have a cool science demonstration for your classroom!

How to use it:

Lets assume there is a uniform magnetic field rising upwards from the floor. If the frame is positioned perpendicular to the field, what is the direction of the forces acting on each side of the frame?

The students are asked to find in what orientation should the red force vectors be attached to each side of the frame - and of course they need to use the right hand rule.

The demonstration continues with the frame set parallel to the floor and also by changing the current direction (simply rotating the current vectors by 180 degrees).

This project was built in the Gelfand Fab Lab, located in the Schwartz/Reisman Center.