I'm new to ARRMA. And just getting back to RC world. I have a granite 4x4 mega. Only thing I have is a 2s lipo battery still brushed. I was playing here few weeks ago and it started acting sluggish finally stalled out and motor burned up. Being less then 3 weeks old arrma replaced the motor. I put the motor in yesterday to I get it out. 15 mins into playing same thing. Sluggish and smoke rolled out of the new motor. Any ideals??
Granite Granite burned up 2 motors?
- Thread starter BigRuss
- Start date
This site may earn a commission from merchant affiliate
links, including eBay, Amazon, and others.
links, including eBay, Amazon, and others.
Oh boy, this is a song that has many verses to it. Unfortunately this is one of many problems with the mega lineup, and if you run 2s in it it'll just keep cookin motors. It'll do decent (at best) if you stick to Nimh, but it just doesn't have enough power to move that truck (without burnin up) in any outside resistance like grass, snow, sand, etc. The best luck I had while staying brushed was using a traxxas titan motor with a heat sync and a fan, but that still burned up too often for me so I put in a mild brushless setup to avoid the neverending motor purchases. If you have some good will power, and stay 2s this will likely do you just fine for good lengths of time. If you drop a 3s in it, you will have to go down the rabbit hole of upgrades including gears, slipper, and diffs. There are quite a few threads on here adressing the problems of these trucks. Do some searching and some reading and you'll find a ton of resolutions for any problems that arise.
- Thread starter
- #3
That really sucks. Ever thing I read show it run the 2s just fine. Guess I'll have talk with arrma. Why advertise saying it can do it when frankly it cant. Very disappointed
Yeah, I agree. The lessons I learned were extensive. I will say however, with this being my first rc it was nice to be forced into working on it. I figured I either had a $220 paper weight, or a $xxx truck. I opted to go all in, and I had a ton of fun doing it. I quickly realized that likely any truck I get will have weak spots and stuff I'm just not happy with, but working on it proved to be half the fun. Doing the repairs and finding upgrades and being able to see huge leaps and bounds in performance was fun and addictive. Meanwhile I picked up a 3s to make sure I had something reliable to run.
- Messages
- 2,503
- Reaction score
- 2,699
- Location
- Tel Aviv, Israel
- Arrma RC's
- Granite
- Senton 3s
- Talion
- Typhon 6s
- Typhon 3s
- Voltage
I have a friend with a Senton Mega, he uses a 7400mah 2s batteries which run for ages (40 minutes). his stock motor holds up fine.
Could it be that some of your bearings are binding? did you service/replace them?
Could it be that some of your bearings are binding? did you service/replace them?
- Thread starter
- #7
It's not even a month old
- Messages
- 2,503
- Reaction score
- 2,699
- Location
- Tel Aviv, Israel
- Arrma RC's
- Granite
- Senton 3s
- Talion
- Typhon 6s
- Typhon 3s
- Voltage
It takes 5 minutes on sand to bind the stock bearings unfortunatly.
It’s really easy to check if the bearings went bad. Dissasemble the driveshaft and motor assembly (one screw), at this point all the wheels should turn freely. If the wheels are good, you also need to check the two bearings that holds the cluch assembly. Remove the cover from the motor assembly (3 screws) and remove the spur gear and check that both the bearings turn freely as well.
It’s really easy to check if the bearings went bad. Dissasemble the driveshaft and motor assembly (one screw), at this point all the wheels should turn freely. If the wheels are good, you also need to check the two bearings that holds the cluch assembly. Remove the cover from the motor assembly (3 screws) and remove the spur gear and check that both the bearings turn freely as well.
- Thread starter
- #9
When I replaced the motor I checked everything all wheels moved freely no binding no roughness. The diffs. Turned freely. Nothing was locked up. This motor lasted 15 mins tops
The Senton should have less rotating mass to deal with thanks to the smaller and lighter wheels and tires. That might be part of the reason it is happier. Also, maybe he drives a bit different than you? I broke my stock motor with 2S LiPo's, but I knew I was going to do it. I ran the truck past the point where the motor started to overheat and just kept going, and I was doing a decent amount of top-speed-in-grass driving. If I had wanted the motor to last, I would have kept a close eye on the motor temp and stopped driving once it got to hot.
The 'problem' isn't so much that the Granite 4x4 Mega can't handle 2S LiPo. It is that using 2S instead of the stock NiMH pack means that the truck doesn't run out of battery before the motor gets too hot. Now, instead of just stopping when the pack dies, you need to stop BEFORE it gives out which is sort of a guessing game. I'm betting that if you consistently ran three or four NiMH packs back-to-back each time you took the truck out, the stock motor would burn out just as fast.
Still, that might be an improvement they could look at for future revisions: adding a temperature sensor to the motor and shutting the truck down when the motor overheats as well. It would certainly be a unique feature for starter brushed trucks.
EDIT: Just FYI, I pulled my motor apart after it died, and it looked like the specific part that failed was the copper arm holding the brush on one side. I couldn't tell if it burned through, melted, or got mangled by debris, but the little copper arm was broken and the brush was just sort of floating around in the motor housing. The broken brush still had plenty of meat on it though, and the second brush was still attached and in good shape. So, the brushes were OK, and the springs pressing them onto the commutator were still springy. It was the arm that holds the brush and transfers the power to it that failed.
Last edited:
- Thread starter
- #11
My 1st motor played maybe 5 or 6 times before. Then we played maybe 30 mins. The about 20 mins later that day. The next day it was sluggish from get go. And could smell the brushes quick.
2nd motor I played maybe 15 mins top nothing had nothing bad same thing happend
DoNoHarm
Very Active Member
- Messages
- 3,099
- Reaction score
- 2,903
- Arrma RC's
- Senton 6s
Did you even break the new motor in?
Also I’d get that new motor right out and buy this...
https://holmeshobbies.com/motors/brushed-motors/trailmaster-series/trailmaster-sport-550.html
Make sure to select the 12t option
From what I gathered the arrma brushed motor sucks so bad people are even replacing them with the Titan 12t made by Traxxas which sucks but somehow is an improvement. Lucky for you you have a brushed truck in 2019 and this new motor is on the market. When I had a brushed slash it was 2010 and we didn’t have a single brushed motor to replace the Titan with, so we all had to bite the bullet and go brushless. Nice to see that someone finally made a good motor.
Also I’d get that new motor right out and buy this...
https://holmeshobbies.com/motors/brushed-motors/trailmaster-series/trailmaster-sport-550.html
Make sure to select the 12t option
From what I gathered the arrma brushed motor sucks so bad people are even replacing them with the Titan 12t made by Traxxas which sucks but somehow is an improvement. Lucky for you you have a brushed truck in 2019 and this new motor is on the market. When I had a brushed slash it was 2010 and we didn’t have a single brushed motor to replace the Titan with, so we all had to bite the bullet and go brushless. Nice to see that someone finally made a good motor.
