hankster
11-12-2004, 08:21 PM
If you are new to RC, the electric motor that powers your vehicle may be a mystery to you. You'll hear other RCers talk about winds, comms, brushes and other things that you have no idea what they mean.
We will dissect a modern electric RC motor and show you what all of these terms mean and help you better understand how your power plant works.
[IMG-LEFT]http://www.hobbytalk.com/bbs1/attachment.php?attachmentid=12639[/IMG-LEFT] Here is what a new motor looks like from the outside. This motor is a rebuildable stock motor based on a design by Yokomo. There are designs by other companies that you may find at your local hobby shop, but basically they are all the same.
Let's take a look at what makes up a modern rebuildable stock motor.
Motor Can: The motor can is manufactured out of steel. It holds the magnets and the bushing for the pinion end of the armature. At the end where the shaft extends, there are two sets of mounting holes for mounting the motor in your RC vehicle.
The End Bell
[IMG-LEFT]http://www.hobbytalk.com/bbs1/attachment.php?attachmentid=12640[/IMG-LEFT] The is the end of the motor that takes care of the electrical connections to your motor. The wires from your speed controller connect to it and through the brushes passes the electricity from your battery to your motor. Made of a non-conducting material, on it is mounted the brush hoods, an armature bushing and capacitors. In a motor that can be rebuilt, two screws hold the end bell to the motor can.
Brushes: The brushes are what actually pass the battery power to your motor and makes it go. They are generally made out of a graphite compound and can have mixtures of silver added for better conductivity. With use, brushes do wear out and will be one of the items that need to be periodically replaced.
Wiring Lugs: This is where your speed control connects to the motor. Each motor is marked a little differently, but if you look closely, one of them will have a + sign next to it. That is the one that you connect your speed control positive motor wire to. The negative wire connects to the remaining lug. Read your speed control instructions closely so you know which wires connect to the motor.
Brush Spring: The brush springs hold the brushes tightly against the armature allowing electricity to pass from your speed controller to the armature while it turns. The brush spring can easily be removed with your fingers by just moving the end of spring out from under the small tab that is on top of the brush hood. You can then just lift it off of the brush spring post to complete the removal.
Brushes: The brushes are what actually pass the battery power to your motor and makes it go. They are generally made out of a graphite compound and can have mixtures of silver added for better conductivity. With use, brushes do wear out and will be one of the items that need to be periodically replaced. They can be removed and replaced once the brush spring is removed as noted above.
Motor Screws: These are used to hold the end bell onto the motor. remove these to remove the armature from the motor
Capacitors: Capacitors are mounted to the motor to help keep radio interference to a minimum. Every electrical motor makes electrical "noise" when they are run. The capacitors absorb this noise so it does no interfere with the operation of your transmitter. You can learn more about mounting capacitors on your motor by reading our How To's where we give easy to follow steps on how to mount them.
Brush Hood: The brush hoods holds the motor brushes in place on the motor and keeps them in proper alignment with the armature. They also include the wiring lugs for connecting your speed control wires and the mounting post for the brush springs.
Bushing: The bushing holds the commutator end of the motor and is what the spinning armature uses as a bearings. Some motors use a ball bearing instead of the stock motor's solid oillite bushing. You should put one drop of oil on each bushing every few runs to make sure it is properly lubricated.
The Motor Can
[IMG-LEFT]http://www.hobbytalk.com/bbs1/attachment.php?attachmentid=12641[/IMG-LEFT] The motor can holds the armature, the magnets and is what the end bell mounts to. Stock motors such as this one has "fixed timing" and the end bell is "keyed" to the motor can so it can not be changed. Some motors have adjustable timing that allows you to "tune" the performance for the motor.
The timing on most stock motors is fixed at 24 degrees. The more timing (up to 45 degrees max) gives the motor more RPM and power, but this also means that it will draw more power and your batteries will not give as much "run time", plus it also shortens the life of the motor.
Magnets: The magnets are glued to the motor can and are what produces the magnetic field that causes the motor to work.
Endbell Mounting Key: Rebuildable stock motors are fixed with 24 degrees of timing. A key on the endbell fits into the slot on the motor can to insure this timing is maintained and that you can only fit the endbell on one way.
Bushing: The bushing holds the end of the motor and is what the spinning armature uses as a bearings. Some motors use a ball bearing instead of the stock motor's solid oillite bushing. You should put one drop of oil on each bushing every few runs to make sure it is properly lubricated.
Motor Can: The motor can is manufactured out of steel. It holds the magnets and the bushing for the pinion end of the armature. At the end where the shaft extends, there are two sets of mounting holes for mounting the motor in your RC vehicle.
The Armature
[IMG-LEFT]http://www.hobbytalk.com/bbs1/attachment.php?attachmentid=12642[/IMG-LEFT] The armature is what spins in the motor and makes you RC vehicle go. Some may shorten the name of this piece to just "arm".
Electricity flows through the brushes into the commutator, the slotted commutor then passes this electricity into the windings. Since the windings are wrapped into a coil, they create a magnetic field when current is passed through them. This magnetic field is repelled and attracted to the magnets in the can causing the armature to turn.
Armature Stack: The armature stack is constructed of laminated steel. It holds the windings of the motor and helps increase the magnetic force created by the windings when current is passed through them.
Label: Rebuildable stock motors are labeled so it is easy to tell if this armature was made for this motor. This is for racing purposes to make it easy to examine the motor to make sure the motor is legal for stock racing.
Commutator: Many times this is called the "comm" by RCers. The comm takes current from your brushes which ride on this part of the armature and sends it to the windings. The comm is not one solid piece, but is actually made up of 3 separate pieces and this allows the current to be switched to the different windings on the armature as it spins. Because it rubs against the brushes as the armature spins, the comm needs to be cleaned after every few runs. You can purchase comm cleaning sticks from your local hobby shop.
Balancing Holes: Armatures are balanced when they are manufactured so they run smoother. This is needed since it is almost impossible to get exactly the same amount of wire on each armature pole. Without balancing, your motor would not run as fast and would wear out quicker.
Windings: Each pole of the armature was wire wound around it. This lacquer coated (for insulation) wire is what the battery current passes though and creates a magnetic field so the motor will run. Stock motors have 27 wraps (or turns) of 22 gage wire. You may hear some RCers refer to this as "winds or turns". Less winds generally means a faster motor and the smaller number of the gage means bigger diameter wire. You will see motors with as few as 8 "winds or turns" and as many as 35 or more.
[IMG-LEFT]http://www.hobbytalk.com/bbs1/attachment.php?attachmentid=12643[/IMG-LEFT] Here is an "exploded" view of a modern rebuildable stock motor. You can use this as a guide in case you need to find out how to reassemble your motor once you have taken it apart to clean or rebuild.
If you have any questions on motors or need any help on how to rebuild or clean, we have many articles on the subject and you can always get help in our discussion Forums.
Good luck and have fun... that's what RC is all about!
We will dissect a modern electric RC motor and show you what all of these terms mean and help you better understand how your power plant works.
[IMG-LEFT]http://www.hobbytalk.com/bbs1/attachment.php?attachmentid=12639[/IMG-LEFT] Here is what a new motor looks like from the outside. This motor is a rebuildable stock motor based on a design by Yokomo. There are designs by other companies that you may find at your local hobby shop, but basically they are all the same.
Let's take a look at what makes up a modern rebuildable stock motor.
Motor Can: The motor can is manufactured out of steel. It holds the magnets and the bushing for the pinion end of the armature. At the end where the shaft extends, there are two sets of mounting holes for mounting the motor in your RC vehicle.
The End Bell
[IMG-LEFT]http://www.hobbytalk.com/bbs1/attachment.php?attachmentid=12640[/IMG-LEFT] The is the end of the motor that takes care of the electrical connections to your motor. The wires from your speed controller connect to it and through the brushes passes the electricity from your battery to your motor. Made of a non-conducting material, on it is mounted the brush hoods, an armature bushing and capacitors. In a motor that can be rebuilt, two screws hold the end bell to the motor can.
Brushes: The brushes are what actually pass the battery power to your motor and makes it go. They are generally made out of a graphite compound and can have mixtures of silver added for better conductivity. With use, brushes do wear out and will be one of the items that need to be periodically replaced.
Wiring Lugs: This is where your speed control connects to the motor. Each motor is marked a little differently, but if you look closely, one of them will have a + sign next to it. That is the one that you connect your speed control positive motor wire to. The negative wire connects to the remaining lug. Read your speed control instructions closely so you know which wires connect to the motor.
Brush Spring: The brush springs hold the brushes tightly against the armature allowing electricity to pass from your speed controller to the armature while it turns. The brush spring can easily be removed with your fingers by just moving the end of spring out from under the small tab that is on top of the brush hood. You can then just lift it off of the brush spring post to complete the removal.
Brushes: The brushes are what actually pass the battery power to your motor and makes it go. They are generally made out of a graphite compound and can have mixtures of silver added for better conductivity. With use, brushes do wear out and will be one of the items that need to be periodically replaced. They can be removed and replaced once the brush spring is removed as noted above.
Motor Screws: These are used to hold the end bell onto the motor. remove these to remove the armature from the motor
Capacitors: Capacitors are mounted to the motor to help keep radio interference to a minimum. Every electrical motor makes electrical "noise" when they are run. The capacitors absorb this noise so it does no interfere with the operation of your transmitter. You can learn more about mounting capacitors on your motor by reading our How To's where we give easy to follow steps on how to mount them.
Brush Hood: The brush hoods holds the motor brushes in place on the motor and keeps them in proper alignment with the armature. They also include the wiring lugs for connecting your speed control wires and the mounting post for the brush springs.
Bushing: The bushing holds the commutator end of the motor and is what the spinning armature uses as a bearings. Some motors use a ball bearing instead of the stock motor's solid oillite bushing. You should put one drop of oil on each bushing every few runs to make sure it is properly lubricated.
The Motor Can
[IMG-LEFT]http://www.hobbytalk.com/bbs1/attachment.php?attachmentid=12641[/IMG-LEFT] The motor can holds the armature, the magnets and is what the end bell mounts to. Stock motors such as this one has "fixed timing" and the end bell is "keyed" to the motor can so it can not be changed. Some motors have adjustable timing that allows you to "tune" the performance for the motor.
The timing on most stock motors is fixed at 24 degrees. The more timing (up to 45 degrees max) gives the motor more RPM and power, but this also means that it will draw more power and your batteries will not give as much "run time", plus it also shortens the life of the motor.
Magnets: The magnets are glued to the motor can and are what produces the magnetic field that causes the motor to work.
Endbell Mounting Key: Rebuildable stock motors are fixed with 24 degrees of timing. A key on the endbell fits into the slot on the motor can to insure this timing is maintained and that you can only fit the endbell on one way.
Bushing: The bushing holds the end of the motor and is what the spinning armature uses as a bearings. Some motors use a ball bearing instead of the stock motor's solid oillite bushing. You should put one drop of oil on each bushing every few runs to make sure it is properly lubricated.
Motor Can: The motor can is manufactured out of steel. It holds the magnets and the bushing for the pinion end of the armature. At the end where the shaft extends, there are two sets of mounting holes for mounting the motor in your RC vehicle.
The Armature
[IMG-LEFT]http://www.hobbytalk.com/bbs1/attachment.php?attachmentid=12642[/IMG-LEFT] The armature is what spins in the motor and makes you RC vehicle go. Some may shorten the name of this piece to just "arm".
Electricity flows through the brushes into the commutator, the slotted commutor then passes this electricity into the windings. Since the windings are wrapped into a coil, they create a magnetic field when current is passed through them. This magnetic field is repelled and attracted to the magnets in the can causing the armature to turn.
Armature Stack: The armature stack is constructed of laminated steel. It holds the windings of the motor and helps increase the magnetic force created by the windings when current is passed through them.
Label: Rebuildable stock motors are labeled so it is easy to tell if this armature was made for this motor. This is for racing purposes to make it easy to examine the motor to make sure the motor is legal for stock racing.
Commutator: Many times this is called the "comm" by RCers. The comm takes current from your brushes which ride on this part of the armature and sends it to the windings. The comm is not one solid piece, but is actually made up of 3 separate pieces and this allows the current to be switched to the different windings on the armature as it spins. Because it rubs against the brushes as the armature spins, the comm needs to be cleaned after every few runs. You can purchase comm cleaning sticks from your local hobby shop.
Balancing Holes: Armatures are balanced when they are manufactured so they run smoother. This is needed since it is almost impossible to get exactly the same amount of wire on each armature pole. Without balancing, your motor would not run as fast and would wear out quicker.
Windings: Each pole of the armature was wire wound around it. This lacquer coated (for insulation) wire is what the battery current passes though and creates a magnetic field so the motor will run. Stock motors have 27 wraps (or turns) of 22 gage wire. You may hear some RCers refer to this as "winds or turns". Less winds generally means a faster motor and the smaller number of the gage means bigger diameter wire. You will see motors with as few as 8 "winds or turns" and as many as 35 or more.
[IMG-LEFT]http://www.hobbytalk.com/bbs1/attachment.php?attachmentid=12643[/IMG-LEFT] Here is an "exploded" view of a modern rebuildable stock motor. You can use this as a guide in case you need to find out how to reassemble your motor once you have taken it apart to clean or rebuild.
If you have any questions on motors or need any help on how to rebuild or clean, we have many articles on the subject and you can always get help in our discussion Forums.
Good luck and have fun... that's what RC is all about!