Brushless Motors Failing

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danl

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Corally RC's
  1. Kagama
  2. Spark
Hello,
I am new to the Corally Brand with a Kagama LE. I got about 50 runs out of the stock grizzly motor before it locked up on me. Upon inspection the front motor bearing was slightly worn but the rotor is showing some delamination and the balancing material appears to have chipped off. Also the motor vibrated the pinion loose. Upon inpsection, there was a bit of dirt in the motor.

I put a HW max8 combo in it and the motor failed on the 5th run. Again the motor locked up. I did not open it up as I intended to warranty it which I did.

So then I put in a new Kuron 825 and did 5 runs. I went to swap it into my Traxxas 6S truck and noticed when swapping over that the output shaft was binding. Upon inspection there was dirt in the motor.

I am wondering if anyone else has issues like this. I figured the first grizzly motor just had a bad part. But then when the HW motor failed so quickly I start asking what am I doing wrong? Then the Kuron 825 has loads of dirt in it.

I'm thinking that dirt is making its way in the 2 unused motor mounting holes? I have left these open as that is how they come from Corally. On the corally design the motor is in line with the front tire which can and does throw debris in its direction. The traxxas 6S truck completely seals the front of the motor. I get 100+ runs out of the traxxas before the bearings go bad.

Thoughts?
 
A chassis dust shroud would be a quick easy fix if dirt ingress is the cause.
 
A dusty motors cover works a treat and I run my kagama 6s in super dusty places only thing that happened to the motor was a bent shaft, running too hard back flipping non stop and landed on power a few times did the trick on that motor.:rolleyes:
 
That’s some seriously dusty/dirty conditions? Motor fans? What kind of temps are you seeing?
I know most every motor useses shielded bearings, I always wondered why not rubber sealed? I mean if the max motor temps are say 200/220, that shouldn’t harm rubber seals? The center diff on these things get just as hot and they use rubber there? You can source rubber sealed motor bearings, might be worth a shot.
That plus sealing any unused mounting holes would be my answer.
 
The HW replacement motor arrived and it is 100% sealed. The mounting holes are blind holes. Maybe the last HW motor failed due to some defect? Motor temps never got over 190F and I run two 30mm fans on it.

The stock corally grizzly motor has open holes and it definitely ingested dirt as its unused mounting holes are through holes. I was going to put aluminum tape over the front of the motor to cover them, but filling them with grub screws is a great idea which I will do if I ever put an open motor back on it.

I'm not crazy about bout a chassis net because I want to get good airflow to the ESC, motor, and battery.
 
To be more accurate, the max I saw in the "peak" section of the HW app was 190F. It mostly runs 140F then towards the end of a run it creeps to 160F. HW says don't go over 90-100C (194-212F). The 190F reading must have been a really quick spike.

Still your feedback is taken and I dropped a tooth on the pinion (down to 12 from 13) and won't run the car as long especially when it is hot out without letting it cool off. I have also installed a temperature sensor that goes directly onto the motor can so that if I can monitor temperatures on motors without an internal sensor like the current HW one.

Another note, I run mostly on 4s. I’m not sure if that increases motor temps compared to 6s. The packs are 9200mah SMC high voltage series.
 
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Nelson.81 said:
190F is way too hot & why your killing motors. Would try to keep it below 160F max.
Click to expand...
It’s up there for sure. I have a Queens hobby 4274 1450kv ($50 from ebay) in my Arrma K6 that I’ve temp’d at 215F several times this summer! Borrowed time I suppose, LOL.
I’m running it on Losi XTT tires w/19t pinion. What’s weird is I was running this same setup with a Hobao rtr 6s esc and the motor never got hot. Well that Hobao esc finally quit after 3 or 4 years. Now I have a Torox 185 in it and the motor runs hot as a pistol. Stock punch settings. Weird. I will say though that it’s way punchier with the Torox installed.
 
KnowAir said:
It’s up there for sure. I have a Queens hobby 4274 1450kv ($50 from ebay) in my Arrma K6 that I’ve temp’d at 215F several times this summer! Borrowed time I suppose, LOL.
I’m running it on Losi XTT tires w/19t pinion. What’s weird is I was running this same setup with a Hobao rtr 6s esc and the motor never got hot. Well that Hobao esc finally quit after 3 or 4 years. Now I have a Torox 185 in it and the motor runs hot as a pistol. Stock punch settings. Weird. I will say though that it’s way punchier with the Torox installed.
Click to expand...
It’s said that the Torox has been programmed out of the factory for a bit more power/speed (higher timing). This would explain the high motor temperatures everyone is seeing with Corally electronics.
 
KnowAir said:
It’s up there for sure. I have a Queens hobby 4274 1450kv ($50 from ebay) in my Arrma K6 that I’ve temp’d at 215F several times this summer! Borrowed time I suppose, LOL.
I’m running it on Losi XTT tires w/19t pinion. What’s weird is I was running this same setup with a Hobao rtr 6s esc and the motor never got hot. Well that Hobao esc finally quit after 3 or 4 years. Now I have a Torox 185 in it and the motor runs hot as a pistol. Stock punch settings. Weird. I will say though that it’s way punchier with the Torox installed.
Click to expand...
Borrowed time for sure, high temps kills magnets , above 170ish magnets can start to Demagnetise they’ll become weaker or demagnetise completely and turn it into a paper weight. Your motor running hotter with the torox esc is because corally has advanced the timing on the torox esc it’s what makes them so spicy, some say it the corally motor that’s hot but it’s actually the esc.
 
Great info everyone. To recap I’ve dropped a tooth on the pinion from stock, reduced punch on the max8 combo from 5 to 3, I’ll reduce my runtimes and allow things to cool, and keep temps below 160F.
 
KnowAir said:
It’s up there for sure. I have a Queens hobby 4274 1450kv ($50 from ebay) in my Arrma K6 that I’ve temp’d at 215F several times this summer! Borrowed time I suppose, LOL.
I’m running it on Losi XTT tires w/19t pinion. What’s weird is I was running this same setup with a Hobao rtr 6s esc and the motor never got hot. Well that Hobao esc finally quit after 3 or 4 years. Now I have a Torox 185 in it and the motor runs hot as a pistol. Stock punch settings. Weird. I will say though that it’s way punchier with the Torox installed.
Click to expand...
Can you link to one? I’m not finding that brand (is it the same as surpass?). I’ve bought a kuron from Jenny’s to get me by, but at $50 these might be a better option until I sort out my truck. I don’t want to keep smoking $120 motors.
 
Nelson.81 said:
Borrowed time for sure, high temps kills magnets , above 170ish magnets can start to Demagnetise they’ll become weaker or demagnetise completely and turn it into a paper weight. Your motor running hotter with the torox esc is because corally has advanced the timing on the torox esc it’s what makes them so spicy, some say it the corally motor that’s hot but it’s actually the esc.
Click to expand...
Spicy indeed! I should probably turn down the punch level, no sense in destroying a good motor. FWIW it still pulls pretty well, for now.. That setup I spoke of has no motor fan so I'm not surprised it's getting so hot. Runtime is down quite a bit from the same batteries as well.
I need to grab a couple HW Quicrun G2 combos next time there's a sale, nice to have spares on hand.
 
danl said:
Can you link to one? I’m not finding that brand (is it the same as surpass?). I’ve bought a kuron from Jenny’s to get me by, but at $50 these might be a better option until I sort out my truck. I don’t want to keep smoking $120 motors.
Click to expand...
You bet!
https://www.ebay.com/itm/3348678166...u9b9Aq4RVDGTcTHJv1eXUSZ7Qe6ITg8Exkega1w&gQT=2
1450kv is pretty low, my plan was to use it in my Kaiju on 6s, but the Kaiju motor mount adjustment range is too small. I couldn't get satisfactory speed out of it so I scrapped the idea. Decided to try the 1450kv in my Arrma after some other failure left me needing a motor for it. Not the most powerful motor, but gets it done for me.
This would be my pick for the Kagama on the cheap..
https://www.ebay.com/itm/3345643466...5FV343&hash=item4de596cafb:g:SEgAAOSwo9divbye

I've also bought several of the Surpass motors from Amazon, including the GoolRC brand which is the same.
RC Juice has some pretty good deals right now too.
https://rcjuice.com/collections/all-around-motors
 
Nelson.81 said:
I’ve smoked pretty much every motor over 2000kv I’ve had 😅. I’d recommend the surpass 4292 1780kv more power & keeps temps at safe level & won’t need to gear it up as much as 1450kv.
Click to expand...
I have the 1650kv 4292 in a Mojo 6s, rips, overkill for me. The one thing I do like about using lower kv is running a bigger pinion, extends pinion life to some degree. 2000kv is really the limit for a heavy 6s truck I feel.
Here's a nice deal on a 4292, only 1500kv, 1780 sold out.. but it'll definitely "do the job".
https://rcjuice.com/collections/all...e-protection-1-8-truck?variant=47576311955751
 
I think the 2250kv from the hw 4278 is just too much kv. If nothing else the rpm it a bit excessive on 6s and combined with my lack of mechanical sympathy with running temps is why they have died.

I’ll get a sub 2000kv motor, preferably larger than the 4278 on order along with some pinions to get the wheel speed back up to mid 40 mph on 4s. In the mean time I’ll take it easy on the 2250 kv hw motor with reduced punch, smaller pinion, and shorter runs.

Then pick up an Asuga when they are back in stock to put the max8 combo into…
 
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