An Alternating Current (AC) Power Source

A direct current battery can also be used to produce an alternating current output by placing the battery into a frame that allows the battery to rotate. Each half-turn of the AC generator causes the polarity of the current to reverse.

Step 1

Fabricate Battery Alternator Parts

CAD Files: Download

Laser Cutter Files

There are three file formats (PDF, AI, SVG). Select the format that is compatible with your machine’s software. 

Laser Cutter Material

To build the motor, we use 1/8″ baltic birch plywood (source: Inventables). If you use a different material, be sure to adjust tolerances on the CAD file.

3D Printer File

There are two files in the downloaded package (9V-Plug and 9V-Cap). Open the 3D printer software and import the STL file, print both files. You will need one of each file per kit.  

Step 2


Begin assembling the parts to the base. The construction follows the same procedures as the linear motor.


Do not install the two center pieces that hold the solenoid tube. These parts are not necessary for this kit. The assembled base should look like the photo on the left.

Step 3


Now, you will need a paper clip for the next part.


Straighten out the paper into one long piece.


Cut two equal pieces of the paper clip.


Install these two pieces of iron into the base. There are two small holes that will fit these two pieces. If necessary, add a small dab of super glue to secure these iron rods into the base.

Step 4


For the next part, you will two pieces of stranded wire (red and black), and two banana jacks with the appropriate hardware.


Install the two banana jacks onto the base, just like the linear motor. Use the washer and nut to secure the jacks to the base.


Now, strip both ends of each piece of wire.


The stripped wire should look similar to the photo of the left.


Connect the black wire to the black banana jack and to one of the two iron rods. You will need to twist the stranded wire around the iron rod. Connect the red wire to the red banana jack and the other iron rod. Solder all four connections.

Step 5


Next, you will need a pair of plyers and a piece of iron rod.


Make one small bend at the top of the iron rod.


Make a second bend in the iron in the opposite direction as before.


Finally, secure the iron rod into the 3D printed part (9V-Cap).

Step 6


Now, grab another piece of iron rod and the other plastic part that was 3D printer (9V-Plug).


Secure the iron rod into the plastic part.


Finally, trim the iron rod and make a bend in it.

Step 7


Now you will need the 9V battery to complete the project. Attach the the 9V-Cap with iron rod to the end of the battery without the metal contacts.


To make the assembly easier, remove one of the wooden posts and slide the hole of the post through the iron rod.


Finally, attach the battery assembly back onto the base. It should look like the photo on the left.

Step 8


Grab the 9V-plug plastic part and attach it to the battery. You will need to guide it through the other wooden post to attach it to the battery.


You should now have the pole reverser fully assembled.