|
Problem |
Cause |
Solution |
| Newly
assembled motor does not work: rotor does not spin. |
| In the starting
position the light from the LED reaches the phototransistor because the disk
blade is not in the optointerrupter slot. |
Make sure that in
the starting position one of the blades is inside the optointerrupter slot and
does not allow light from the LED to reach the phototransistor. While holding
the magnets, slightly rotate the cap with the disk to find the proper disk
blade position. |
| Rotor is jammed. |
Find the exact
cause and fix the problem. This may require breaking off the stands and
reattaching them to the board. You may try to lubricate the axles with WD-40
or any other lubricant. |
| Electromagnet
attracts the magnets instead of repelling them. |
Switch the
electromagnet wires. |
| Bad connection in
wiring. |
Thoroughly clean
the wires to remove the insulation before soldering. Re-solder the
connections. |
| Intersecting
connections in wiring. |
After soldering
check all the connections to make sure that they do not touch each other. |
| The battery is dead
or battery voltage is low. |
Get a new battery.
Increase the voltage by adding an extra battery. The lowest voltage for this
motor is 3V, though sometimes it may not start at this voltage. |
| One of the magnets
is not repelling. |
Tear this magnet
off and glue it upside down. All of the magnets should have the same pole
facing outside. |
| The optointerrupter
is connected incorrectly. |
Make sure that you
connected the optointerrupter wires according to the wiring diagram. |
| The optointerrupter
was burnt and does not work. This may happen if you connected it improperly or
used high voltage. Even a brief connection of the optointerrupter wires
directly to the battery may destroy it. |
Replace the
optointerrupter. |
| The transistor is
connected incorrectly. |
Make sure that you
connected transistor leads according to the wiring diagram. |
| The transistor was
burnt and does not work. This may happen if you overheated it while soldering,
connected it improperly, or had the rotor stalled on a high voltage. |
Replace the
transistor. |
| The light from the
LED reaches the phototransistor because the disk is semi-transparent. |
Blacken the blades
with permanent marker or glue additional pieces of opaque material, such as
aluminum foil, to the blades. |
| Motor
worked fine for a while but then stopped working. |
The battery is dead
or battery voltage is low. |
Get a new battery.
Increase the voltage by adding an extra battery. The lowest voltage for this
motor is 3V, though sometimes it may not start at this voltage. |
| The transistor is
burnt. |
Get a new
transistor and re-solder it. Try not to leave the motor stalled, this may be a
reason the transistor was burnt in the first place. |
| The optointerrupter
is burnt. |
Replace the
optointerrupter. |
| The
transistor is getting too hot even when the motor works. |
The rotor has too
much friction. |
Make sure that the
rotor spins freely. You may add a heat sink to the transistor for better heat
dissipation. You may also try to lubricate the axles with WD-40 or any other
lubricant. |
| The disk blades are
too wide. (If you made a disk yourself or glued the pieces of opaque material
to the blades) |
Trim the blades
with scissors. |
| Dirt in the
optointerrupter slot may interfere with the light beam. |
Clean the
optointerrupter slot. |
| The
electromagnet gets hot. |
Not enough wire
used for the electromagnet. |
Make sure that the
electromagnet coil has enough wire. Use all the wire from the spool. |
| Short connection
inside the electromagnet. |
Re-wind the
electromagnet. It is better to use a new spool of wire, but sometimes the old
wire may still work. |
| The motor speed is
too slow. |
The disk blades are
too narrow. |
Make the blades
wider by cutting the disk with wider blades or gluing 4 pieces of opaque
material to the disk blades. |
| If you need to
disassemble the rotor… |
|
This operation
requires quite a bit of strength. Disassemble the rotor with a rocking motion
as if trying to break it and at the same time pulling the ends out. |