Building the Linear Motor

A Linear motor is a simple electromagnetic device that is capable of moving in two directions.

Steps: 8

Step 1

Fabricate Motor 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 is a single file in the downloaded package (end-cap). Open the 3D printer software and import the STL file, print four end caps for the motor. 

Step 2


Assemble the laser cutter parts together to build the body of the motor. The pieces should press-fit together. A hammer can be used to tap in parts into the corresponding holes.


Press the spool holders and the end stops into the motor base.

Step 3


Finish the assembly of the motor body by attaching the four feet to the bottom of the base. Again, use the hammer if necessary.


At this point, the motor body assembly should be completed.

Step 4


Assemble the two banana jacks onto the motor base. There are two holes cut out towards the back that will fit the jacks. You will need to unthread the nut and remove the washer. Attach and tighten the nut and washer onto the base.


Here is how the banana jacks should look after you attach them to the base.

Step 5


You will now need to use the solenoid made in the previous unit. There should be two trough pieces that connect to the end of the solenoid. Gather all of these pieces.


Attach the two trough pieces to each end of the solenoid. These will guide the magnet in and out of the solenoid.


Finally, attach the solenoid assembly onto the motor base. The troughs should rest on top of the motor base as shown in this photo. Guide the two ends of the solenoid wire through the small holes located below the solenoid tube on the base. 

Step 6


You will need to solder the two solenoid wires onto the terminals of the banana jacks.


To make the soldering process easier, take each wire from the solenoid, remove the red insulation coating, and wrap it around the terminals as shown in the photo. This will keep the wire in place as you try and solder it.


Finally, solder the wire to the banana jack terminal.

Step 7


Gather the following materials: permanent magnet (1), 3D printed end caps (4), and a piece of coat hanger or iron rod. You will need to cut the iron rod into two pieces: 25mm and 15mm.


Use a hammer to tap the iron rod into the end caps.


Assmeble the motor’s armature by attaching each iron rod (with end caps attached) to each side of the magnet.

Step 8


Place the armature inside the solenoid tube. You may need to detach one of the iron rod assmeblies from the magnet, and then reattach it when it is inside the solenoid tube.


Here is a photo of the final motor assembly. You are now ready to test out your motor and make it move!