doyree

hi

i recently bought a used elec. 4-tec with upgradedmotor.
i took it out for a test drive withfullchargedbattery (very old battery), car just stopped running afterlike 30 secs.
when i checked the car, its steeringwas still working but it justwasn't goingforward or backward.
but thefunny thing is that when i gave it a little push, it started going again. then after about 20 secs drving, it would stop.
i give a push again, then it would run again.
this happens the most when i run it at lower speed but when i run it at full speed without stopping, it dosn't seem to happen.
what could be wrong with the car?
motor? esc? battery? please help!

p.s. battery is very old and i think it lasts like 3 mins even with full charge.


thanks!!!

SyCo_VeNoM

try new batteries...
the servo uses ALOT less juice than the ESC and drive motor. The battery probably isn't supplying enough to the ESC.

glattica

Go to [link=http://rcsuperstore.ning.com/]RC Superstore[/link] to order all of your HobbyKing Parts. View and add your own videos. Create you own page to
keep all of you RC Stuff.

SyCo_VeNoM

or people can just go straight to hobbyking.com instead of navigating that horrible (imo) site seeing it just links to hobbyking anyways...

BigTb17

Very possibly a bad motor. Old battery doesn't help either, but those symptoms sound like a possible motor issue. The commutator could be burnt/worn bad enough that it you stop the brushes aren't getting good enough contact to start the motor spinning. If you give it a bit of a push the motor starts spinning and the brushes/com. get good enough contact to stay working once in motion.

If your going to get another battery anyway you should probably try that first. It's hard to tell without being able to see what it's doing, so it could be a battery issue. But don't be surprised to find you need a new motor too (or at least new brushes). You could also try spraying the motor out with motor cleaning spray (don't forget to oil the bushings/bearings after you do this). It's possible that the brush holders are simply dirty and the brushes are hanging up. A good cleaning may correct the problem.

Good luck.

doyree

thank you very much.
i needed to ordered the battery anyhow.

still, when i gave it a little push after it hadstopped, it was running fast again.
hmmm

doyree

bigtb17,

wow
you were right on money.

i did some research on cleaning out the commutator and then i took the motor apart and started cleaning it with some q-tips.
lot of black residue stuff came right out and after cleaning it, i mean it still does stop but not as much as before.
it was like 75% less stopping than before!

i definately need to get that motor cleaner thing and clean it out again!!

thanks!


now, i got a nitro 4tec with broken carb.
ordered the part and hopefully u can give some tips on that too later

thanks again!

neyou86

My Feedback: (2)

try spraying some wd 40 on the commulator. its what the brushes sit on.

BigTb17

WD 40 could cause arcing and possibly damage the commutator. There is a specific comm lube you can buy that is dielectric (non-conductive, prevents arcing). I've never used it though, so I can't say how much or little it would help.

doyree

just returned to thank you again for your tip.

i went to autozone, purchased bottle of elec. cleaner(crc lectra-motive)and wd-40

disassembled motor, let it sink in motor cleaner for few mins, took it out and dried/cleaned w/ q-tips (wow stilllot of black residue even after initial clean!!)
After motor got dried, wd-40ed it then reassembled the motor.

went out for a spin and baaam!!! the car looked at me and asked, "stopping? what's that?"

thanks bigtb17!!!!

If anyone is having simmilar issues like slow motor or motor not working or stalling or any sort,
disassemble motor, clean/dry it, and lube it! it will run like new again!!!!

tip: any newbies like metrying todisassemble theelec. motor, be careful of the rings on both sides of the shaft after opening it.
they are tiny little pcs that you could easily lose or if lucky like me, they be magnet/stuck inside motor shell!!

mbrox

Hey, dunno if this is really relevant, but i haven't figured out how to start my own thread yet. I was wonderring if anyone could gimme a little electrical advice. I build robots for a state competition, and my robots seem to stall if i try going from 0 volts to 14.4 too quickly. This has become very annoying, because in the heat of a battle, i have too slowly increase the voltage to the max to avoid the motors locking up.

i'm basically wondering if this is an inherent property of brushed motors, my saber tooth dual speed control, or just me being an idiot and miss wiring my motors. I've also noticed on the thousands of motors i've ripped out of toy rc cars that there is a capacitor solderred between the leads. My robot doesnt have this, and i was hoping someone could tell me if i  do that to my motors will it allow them to do that high voltage jump.

thanks everyone, i really dont have enough finess to bring the power of the motors up slowly in the middle of a sumo fight XP.

mbrox

this is for your previous prob, and if it starts happenning again.

also, if its an old/used battery it might have been treated wrong, and doesnt work very well. this happenned to one of my friends, and the problem was he broke the battery. he was using a NiCad battery, and didnt drain it fully before recharging, which destroyed the available charge in the battery and it now only runs for like 30 secs. Check the battery life and make sure you treat the battery properly. just cuz u said ur new to this man, i'll assume u dont know the different types... just in case u know its not like im selling u short.

NiCad- Nickle Cadmium- must be fully discharged before recharging or it will develop a memory (will only discharge to the point where it was previously charged

NiMH- Nickle Metal Hydride- do whatever the hell you want with it. it wont matter... well so long as u dont burn it or something.

LiPo- Lithium Polymer- you MUST NOT fully discharge these, as i learned with my laptop. if these die they will not hold a charge for ore thn a few minutes and die. these are the most energy dense batteries, which is y they are expensive and last the longest and are the lightest. but beware! you must use a special LITHIUM POLYMER CHARGER.

john01374

My guess is you have only temporally solved the problem by cleaning to motor. Typically when a motor starts acting like your the brushes are worn out and making poor contact with the comm. Cleaning the motor will get it running again but it will only last until the brushes wear a little more then it will start happening again. The fix is to replace the brushes. It takes all of 2 minutes and costs about $3.