Difficulty level: 1 (simple, no special tools required)
Click here to purchase these inexpensive and simple kits.
Read all instructions carefully and check the Safety Rules before you start!
This is our version of the simple conventional brushed motor for groups of students. It is very inexpensive kit (only $4.99 per motor!).
If you buy 2 sets or more you get free RPM measurement attachment – your students will be able to compare the speed of their motors (frequency measurement multimeter required; if you do not have one you may buy it in our store).
If you buy 4 sets or more you also get free Rapid Assembly Basic QuikLock Reed Switch Motor Kit #12!
Please note: Though this kit looks like the simplest motor it requires a lot of accuracy in balancing the coil and stripping off the insulation. It is also not a very reliable motor. It is actually easier to assemble any of the reed switch motor kits shown at our site. They are much more stable, reliable, may run non-stop for a long time, and are powerful enough to do some work while practically nothing could be attached to this motor.
Students usually understand quicker the principles of the reed switch motor operation and these motors have a proven record of working every time without any struggle.
This is not a brushless motor as opposed to most other motors on our site.
- Leave about 3″ (7-8 cm) and wind the wire 10-20 times around the AA battery. You do not have to be neat as some randomness does not affect the motor performance and may help the coil to hold its shape better. Leave 3″ (7-8 cm) at the other end of the coil.
- Carefully remove the battery and wrap the ends around the coil 2-3 times to hold the coil together with both ends extending perpendicular to the coil as shown below. The ends should be aligned in a straight line to form a good axle. This step requires a lot of accuracy because the balance of the coil is extremely important.
- Strip off the insulation completely at one end and only half of it at the other. This step is very important, try to be very accurate.
The following picture shows how to remove the insulation using the knife. Do not scratch the table – put a piece of cardboard or similar material on it. Hold the coil in vertical position with one of the ends lying on the surface and remove the insulation by moving the knife in the direction shown with the arrow. Hold the blade of the knife in vertical position. You will need to rotate the coil slightly in both clockwise and counterclockwise directions to remove half of insulation, and rotate the coil 360° to remove the insulation completely from the other end. Apply only a slight pressure or you may cut the wire end off.
- Fully insert two metallic stands into predrilled holes in the board. You might need to push hard or even hammer the stands into the board.
- Attach the battery holder to the board and connect its wires to the stands as shown below.
- Attach double sided sticky pad to the magnet.
- Attach the magnets to the board between the stands.
- Place the coil on the stands and try to spin it slightly. Well balanced coil should spin freely. Ideally it should stop in random positions. Take time to balance it. You might need to move the ends up and down along the coil slightly to find the most balanced position.
- You may add two beads on the coil ends. These beads reduce the friction between the coil and the stands.
If you want to measure the speed of your motor bend the coil ends as shown. Visit http://simplemotor.com/motor-speed-measurement/ for information on how to measure the speed of rotating coil in RPM.
Your motor is ready! Depending on the coil position the motor may start immediately or you might need to give it a slight push. The motor usually spins in one direction so you should try to spin it slightly in both directions.
If your motor doesn’t work, ensure that the rotor is balanced and can rotate freely and check the insulation. Properly removed insulation leaves shiny copper on one end. Half of the other end should also have shiny copper color while the other half should be the color of the original insulation as shown in step 3. Make sure the battery is fresh. If the motor still does not work – check Troubleshooting section.
Clean carbon buildup (black stuff) on coil ends and metal stands often.
CAUTION: Do not leave the motor connected to the battery if the rotor is stalled. This motor consumes a lot of electricity and could drain the battery quickly even if it does not spin.
How it works
When un-insulated (bare copper) parts of the coil wire contact the metal stands the current from the battery flows through the coil making it an electromagnet with North and South poles. This electromagnet interacts with the permanent magnet (North and South poles attract each other while the same poles repel). Motor starts to spin until the contact is broken when an insulated part of the coil end comes into contact with the stand. However the coil continues to spin due to inertia and then the process continues. Technically speaking this motor is a single pole pulse motor.