Ok, I'm here for perhaps the least understood and often times most blamed part of one's AEG, the motor.
Motor Parts :
The "Can"-This is the part that holds, the armature and the magnets.
The Endbell-This is the part of the motor that holds the brush & brush springs
Brush-almost always copper with a bit of silver or carbon, this is the motor's main contact point, this is where all that custom battery's power flows to make the armature rotate
Brush Spring-it presses the brush and keeps it within the brush hood to make sure the brush remains in contact with the com.
Tension Spring-It provides a counter tension to the motor when inserted into the gear slot
Pinion Gear-this is the main drive gear that directly provides power to the spur gear
Armature-this what's inside your motor, typically it has 3 main sections where the coiled wire runs through ( more on the wind & turns later ) this is topped off by the commutator
Commutator- or just plain "com" is where your brush presses into and where the power flows into the armature, it's made out of copper with 3 separators, it's "cut" into 3 sections just like the armature's main wire winders.
Ok ... Ok So my motor has many many parts that I won't see ( ever ?! ) but how does it work and what is a wind and what is a turn ?
Turn - refers to the number of times the insulated wire ( the one looped into your armature ) loops into your armature, the stock motor has 28 turns, the less the turn the faster the motor ( also consumes more power )
Wind - refers to how many wires are bunched together to make the Turn in that armature, the stock motor has a single wind, the less the wind the more torque and the bigger the diameter of the wire ( a single wind motor has more torque than a same-turn motor with more winds )
Stock Motor = "28 turn single" ( 28 turns using single wind )
Torque Up Motor = "24 turn quad" ( 24 turns using 4 winds of smaller wire )
( note, the above is an approximation as each manufacturer has their own builds, but it's not too far off )
ok now I know what the motor "rating system is about" so what's this about maintenance ? I mean it's inside my hand grip so what's there to maintain ?
- practically nothing, but in case you put too much stress on your motor inadvertently it would not hurt to check up on the following parts :
Motor Brush Spring & Motor Brush Hood, is the Motor Brush Spring Still pushing the Brush into the hood ? ( you do need to take this out to check the brush conditions ) once you have both of them off, place it side by side and check if both are the same shape, some springs when they overheat the motor gets soft and deform a bit, they no longer provide proper tension to the brush, causing the motor to stop during operations sometimes, then start again when jolted. check the brush hood if it's still lined up correctly.
Motor Brush Conditions, is the brush chipped in any way ? is it discolored ? clean the brush with alcohol, do not leave any residue as this will cause a fire. also make sure that it is not worn out ( shorter than what is normal, they wear out just like a car's brake pads over a period of time, something that is accelerated in modified or high torque motors )
now to take out that endbell so we can have a look at the com & armature ... ok, see that "post" that the brush spring was on ? it has a small hex-head on it's bottom, if you can unscrew this with either a needle nose pliers or a hex drive then we can get in that endbell !!
Com Conditions, finally we are here at the heart of the motor, check for chips, discoloration and wear ( why would it wear out ? a burnt brush that got chipped will wear away the com real fast, and a chipped com will eat away at that brush ) often times a severely worn brush is tell tale sign of a bad com or scratched com , a scratch com you can polish but a chipped com means you need a new armature.
Armature, nothing much to check just make sure the wires are not burnt or the magnets inside the can aren't chipped.
Pinion Gear, finally the last thing to check, inspect for damage to the gear teeth ( for the curious it's a 48 pitch teeth beveled pinion gear ) for proper tension, the ideal was to have a paper-thin width between gears, that way the gears spin freely and do not bind, but at the same time is not too lose as to allow contact at the tip of the gear teeth only resulting in stripped gears,I used to practice the "feel" by running a small strip of paper between my gear mesh to check ( using a dummy gearbox of course ) once i got the hang of it, i can tell just by the sound my gears make.
a few notable things i have encountered that can be traced to a faulty motor
-someone upgrade their AEG spring to somewhere around SP140, the result was that the fuse kept on blowing, what does junior do ? why of course get a BIGGER fuse with a higher rating as advised by some sages in a forum that shall remain nameless for now ... the result ? the motor com developed a chip and causes random "jams" or stoppage whenever the damaged brush and com stop at a certain angle to each other, the techs at a shop that shall remain equally nameless ( it ain't ASGI, don't worry ) could not pin point the location of the "jam" because they keep looking inside the gearbox for the problem ... they "ran" the motor uninstalled from the gearbox ( no load means no stoppage according to piston/gear orientation ) and it worked "ok", they even checked the mesh, if the genius only bothered to look in the brush hood or what's left of the brush ...
hope this helps clear up some motor myths ( there is nothing to fear from your motor, relax it isn't too hard to understand how it works )
well, hope this helped our newbies a bit ( remember Newbs,newbies, & novices aren't NOOBS, NOOBS are a different breed altogether )