Building the Linear Motor (Cardstock Version)
A linear motor can be a gateway to exploration of topics that include electromagnetism, force and motion, mechanical and electrical waves, and sound and vibration. It also can provide a building block in design of kinetic mechanisms and art.
Fab@School Maker Studio was developed as a design tool to support the design process in Maker Spaces. It was developed through a public-private partnership between non-profit The Reynolds Center for Teaching, Learning, and Creativity, the educational software publisher, FableVision Learning and a number of educational collaborators that includes the Laboratory School for Advanced Manufacturing.
The design for a linear motor developed by Eric Yoder and Elizabeth Smalley has been incorporated into the Fab@School Maker Studio Ready-Made Projects library. This design supports fabrication of a linear motor with inexpensive materials such as card stock. The design can be printed on an inkjet printer and cut out with tools such as scissors. Another option is to use an inexpensive digital die cutter such as the Silhouette Portrait (cost approximately $150) to automate the process of cutting out the pieces. This makes it possible to quickly make changes to the design through a series of successive iterations that is at the heart of the engineering design process.
Materials & Resources
The following materials and resources are needed for the project.
- Fab@School Maker Studio
- Silhouette Die Cutter
- Inkjet Printer (Color)
- Cardstock (min: 6 sheets)
- Glue stick
- Magnet Wire (32 AWG)
- Electric Spool Winder
- Iron (Coat Hanger)
- Permanent Magnet
Fab@School Maker Studio
Access Fab@School Maker Studio at www.FabMakerStudio.com.
Fab@School Maker Studio is a cloud-based program that can be accessed online using a web browser. Once you secure a Maker Studio account (available from FableVision Learning: http://shop.fablevisionlearning.com/fabschool-maker-studio-/fa/shop.detail/productID/2957/#.V-Fo65MrJZ0), you will be able to open and log into Fab@School Maker Studio.
From the Ready-Made Projects Menu Open the Linear Motor Invention Kit
The Linear Motor Invention Kit can be accessed through the Fab@School Maker Studio Ready-Made Project menu under 3D-Stuff. Once you have opened the Linear Motor Invention Kit, send the design to a color printer. Print the file at 100%. Do not scale or fit to page. This will require 8 sheets of card stock.
Cut Out the Design Elements
If you do not have a die cutter, you can use scissors to cut out the design elements. If you have a Silhouette die cutter, you can send the Linear Motor Invention Kit to the Silhouette.
That icon will provide access to a dialog box, “Send to Cutter,” shown below. Once the Silhouette cuts and scores the design elements on each of the six sheets of card stock, separate the design elements from the card stock. (Or, if you do not have a die cutter, assemble all of the pieces that were manually cut out of the card stock using scissors.)
Assemble the Motor Support Components: Part 1
The motor support components include a base and supports designed to hold a solenoid that is a key component of the linear motor. A solenoid consists of a tube, created with card stock in this instance, with many wraps of magnet wire around it. When an electrical current is sent through the solenoid, it generates a magnetic field that moves the motor back forth.
(A) Assemble the Solenoid Supports
Fold and glue (1) the two solenoid supports, (2) the end pieces that limit the movement of the motor, and (3) the solenoid support bar, as shown below.
When all five pieces (two solenoid supports, two end pieces, and the solenoid support bar) have been assembled, they will look like the illustration below.
(B) Attach the Solenoid Supports and End Pieces to the Base
Insert the two solenoid supports and the two end pieces up through the base as shown below. Glue the tabs on the bottom side of the base.
(C) Insert the Support Bar
Glue the support bar to the base and to the tabs attached to each end piece.
(D) Fold down the sides of the base and glue.
Assemble the Motor Support Components: Part 2
(A) Fold the corrugation and insert in base, as shown below. Attach with glue or tape.
(B) Assemble the Top Piece.
Fold and glue the side tabs of the top piece to construct right-angle triangles, as shown below.
(C) Assemble the Side Pieces
Assemble the side pieces as shown below on the left. Once the side pieces are assembled, they should look like the photo on the right.
(D)Attach the Sides and Top
Glue the sides to the base as shown below. Then glue the top to the sides.
Assemble the Solenoid Tube
In addition to the four discs and the rectangular piece shown left and center below, you will need a 3/8” diameter magnet and a piece of scrap cardstock about 6cm x 6cm. The scrap cut from the center of the side piece in Step 5, g. works well for this (shown right in the photo).
Roll the cardstock scrap tightly around the magnet and secure with tape.
Roll the rectangular piece tightly around the magnet and the cardstock scrap. Secure with glue.
Glue the four discs to form two thick discs. Slide these discs onto the tube. The discs should be about 4 cm apart. Secure with glue.
Once dry, pull the cardstock scrap wrapped around the magnet out of the glued solenoid tube. Remove the magnet from the scrap. The solenoid tube is ready to be wrapped with magnet wire.
The motor consists of a solenoid (magnet wire wound around a cardstock tube), a permanent magnet, and two motor rods (sections of a wire coat hanger).
(A) Construct the motor rod assembly.
The motor rods (sections of coat hanger) will be placed on either side of the permanent magnet. The motor rods are suspended from two supports attached to the top. Attach the supports to the motor rods by folding the bottom tab overtop of the wire as shown below.
Then secure the wire by folding long vertical tabs overtop of the tab. A wave that will project through a slot in the top is then attached. When the motor moves back and forth, the waves will also move back forth.
(B) Complete the motor.
Place a permanent magnet in the solenoid. Then insert the solenoid between the two motor rods, as shown below, attaching the rods to either side of the permanent magnet. Because the metal of the coat hanger wire is ferrous, the magnetic attraction of the permanent magnet is sufficient to secure the rods.
The final assembly involves two steps. The boat and associated waves are attached to the top. Then the motor is placed on the motor supports to complete the construction.
(A) Attach the Boat
Attach the boat and second set of waves associated with it to the top, as show below.
(B) Insert the Motor
The motor is placed on the motor supports, as shown below. The wave pattern attached to the motor assembly projects through the top. When the motor moves back and forth, the waves also move back and forth.