E-REVO POSSIBLE MOTOR problem

[hootie7159]

whats up guys... i'm just recently converted my revo 3.3 into brushless...
-mamba max esc w/ ubec and fan w/ holes in case
-feigao 540c 8xl motor with fan on top
-5s 8000 truerc lipo batt
-geared 16/40 mod1 pinions and spur (both steel)
-stock revo tranny locked in 2nd gear with center diff
-mechanical front and rear disc brakes (used on third channel)
-esc still has reverse enabled
-stock settings on mamba w/ cutoff at 15.8v

anyways, i've run my 4s 8000 in my e-revo with no problems..however, wen i hooked up my 5s, everything was going fine (5min into the bash session) until i heard a grinding sound coming from the car...i immediatley stopped and took it home to see what had happened....well, it wasn't the pinion or spur gear and i've replaced the entire tranny (old tranny was fine couldn't find any stripped gears) put it back together and still the grinding sound...then i replaced both the front and rear diff put it back together and still the grinding...so now i suspect it was the motor...the grinding only happens when a load is palced on the rear wheels and when i gun it to full throttle from a stanstill...its definitly not cogging but grinding is too loud to pinpoint exactly where the sound is coming from...let me know what you guys think...i've already orderd a neu 1515 2.5d and i'm just wondering why this happened and if this motor is salvagable...thanks oh yeah...mamba arms perfectly fine and switched the batts to 4s and my 3s and the grinding sound still comes form the motor....

[gtxracer]

Take the system off the car and try it like that.

Did you have problems stripping spurs with all the power? That's what I'm going through right now. Who makes your steel spur?

[suicideneil]

Grinding under load.... could be the magnet on the rotor is broken, but you would need to open her up to be certain. test it off the truck to be certain, but if everthing else is fine, it has to be the motor.

[hootie7159]

thanks for such quick replies...the system and motor runs fine when i take the system out and run the motor with or without a pinion against "air"...
i tore down the motor and 2 questions: 1. Are the magnets supposed to come apart (there are 2)? and 2. I used locktite to keep the endbell on...will this mess up the motor?

....when i take it to WOT the motor runs smooth with all three battery types...it also took removed the esc from its casing and i see no burn marks as well ...by the way, i have no idea who makes the spur i'm using since it came with the revo after i bought it off ebay a few months ago, its pretty sturdy and i have not stripped any spurs or pinions.... ...i still don't know whats wrpong with the motor being that it only went through 5 runs....twice on 3s (fast)...twice on 4s(faster)...and the one and only final time on 5s () this thing was fast!!! and "WAS" being the key word now at least until the NEU comes in....

[suicideneil]

Do you have a nother motor to test, just in case? Im guessing not though. One more test you can do is to roll the truck back and forth by hand, with no motor/pinion in place, and turn the diffs whilst holding a wheel still etc, to see if there is any grinding occuring. The Neu motor will be a big improvement though, a worth while investment- your MM works okay on 5s you said... must be an older model = lucky devil.

[hootie7159]

rolls pretty good...i got + opposite rotation on both front and rear wheels and flawless free rolling ability with no grinding... ....and yeah i finally broke down and got a NEU from www.amainhobbies.com were on sale for
$259.00 with free shipping and if your a member you can get an additional $25.00 off so after taxes and the free shipping I got it for about $252 which i believe is the cheapest I've found on the internet (this company is based in Chico, CA. and I live in Sacramento, CA. so the product comes relatively quickly anyways AND yes, i have 2 older MM's... i bought both about a year ago...the temps after a 45min. run on the 4s = 120 w/ fan...ah well guess the 8xl is now toast...i don't understand though b/c it was rated to run up to 5s ..can't wait for the NEU...

[crazyjr]

does the motor still run but not the pinion when you hold the truck down? That would be a seperated rotor, I have had the same thing happen twice. Once with a novak HV and once with a lehner basic XL1200, I fixed both with JB Weld ( the good stuff, not the quickset) Not sure if it will work on a fegaio, as the shaft looks small where the manet sits

[Patrick]

Wheel hexes? One of my rims that rounded out sounded like a blown diff.

[hootie7159]

CRAZYJR: i'm umfamiliar with the internal anatomy of a feigao but there are two magnets and and they both come apart...i didn't take apart the motor until i had this problem so i'm not sure if they are supposed to come apart or not...and i'm guessing if they aren't then i'm supposed to JBWELD the two magents together ? The motor eventually runs but the REVO doesn't get up to top speed and if I mash on the throttle from a standstill it does the grinding sound for a couple of feet until i let off the throttle and ease into acceleration....Thanks for the suggestion and it doesn;t hurt to try this since i'm getting a NEU anyways...if it works maybe i'll throw it in my rustler

PATRICK: its not my wheel hexes...just checked all four of them and i totally know the feeling when you've stripped your hexes...my crawler ate up its axial beadlock hexes but JBWELD fixed this problem as well


They should change JBWELD's name to IT FIXES EVERYTHING GLUE..

[squeeforever]

I'm pretty sure you ruined any chances of fixing it since you've obviously run it after it came apart...

According to this, there's supposed to be a black marker line to align the 2 pieces of rotor so you should be able to get the mag field right again. You've lost any balance though between rotor and shaft.

http://forums.radiocontrolzone.com/s...d.php?t=241379