New Motor/ESC issue

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MasterOfPupets

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So, installed a brand new Hobbywing Max10 G2 140amp ESC and 2400kv G3 motor. It's a sensored setup.

Ran it yesterday on 3s and it worked fine.

Ran it today on 4s (just got batteries in) and it worked fine initially (only ran about 30 seconds, was doing standing backflips), but it actually sheared off my pinion lock bolt and started the motor free spinning. I put in a new bolt and it runs fine when holding it in the air, but when I'm actually running it now has a stutter issue on takeoff (I've got a video I can't figure out how to upload here) where it wheelies and stutters (doesn't flip itself over.)

Any ideas what the issue could be? I'm charging up the second battery now to see if it could be just the battery not putting out as much power (cell checker shows the other battery at 4.15V per cell average, so it's not exactly drained) but I'm doubtful. I'm also going to charge a 3s to see if it does it on 3s now.

Any thoughts or troubleshooting I should try? My thoughts are center diff slipping, current issue, or possibly gearing.
 
replace censor wire. I dint see anywhere its 4 cell friendly only 3 cells. .
 
I uploaded the video ow what it's doing onto YouTube.


It has no issues at low speed, only surges when I hammer the throttle. I'm the video I was full throttle as it was bouncing.

I really hope it's not a problem with the sensor wire, since it's not replaceable...
For reference, this was the first test on 4S before it sheared the pinion screw


This was 3s testing the day before without issue (I actually ran it around outside this morning on 3s for 15 minutes or so)


And this was my initial testing on 2s with no issues.


I made no mechanical or electrical changes between any of the videos except swapping the batteries and replacing the pinion screw...
 
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Did you set the ESC to auto-calculate the LVC or is it still set to 2S?

Might be surging if the voltage doesn't match up.

Another thought is you may have damaged the motor if you ran the motor unloaded without a pinion for too long... if you go too high of an RPM you may have damaged the rotor where it may be physically hitting the stator at high RPM's... will need to take apart the motor to inspect the rotor to see if this is happening.
 
Did you set the ESC to auto-calculate the LVC or is it still set to 2S?

Might be surging if the voltage doesn't match up.

Another thought is you may have damaged the motor if you ran the motor unloaded without a pinion for too long... if you go too high of an RPM you may have damaged the rotor where it may be physically hitting the stator at high RPM's... will need to take apart the motor to inspect the rotor to see if this is happening.
ESC is set to sense the lipo. It beaps on startup the number of cells it detects, so I should have noticed if it was set to 2s (no guarantee I did though)

I pulled the RPM reading and it shows 30563 which should be fine since it can theoretically go to 35000+ at nominal voltage on 4s (14.8V * 2400kV = 35520) so it should be good for even higher (16.8V * 2400kV = 40320) unless I just don't understand the ratio of kV to RPM like I thought I did (again, possible.)

Also, it has no problem spooling up to high RPM when there is no load (holding the car in the air) it only happens under load (ie acceleration) so I'll pull the motor apart, but if that did happen it would have to be a manufacturing issue.


Did some more testing. No stutter at all on 3S. 4S still has the issue, regardless if I use a partially discharged pack (16.6V) or a fresh pack (16.8V). Both packs are brand new Zeee 4S 5200mah 100C packs. Started messing with ESC settings, and no change regardless of if I set the voltage directly or let it auto-detect. I started messing with the punch setting, and was able to determine that is functions fine at punch 7, but the stutter starts at 8. I had forgotten I jacked the punch up to 9...

My read on that is that it's a current issue and the truck just can't pull enough for the initial hit using punch 9 (could be batteries, wires, solder joints, who knows). Am I interpreting that wrong?
 
Hmm, thinking that the cogging may be a sensor issue, assuming you re-connected the sensor wire in both the ESC and motor, you might have damaged the sensor board in the motor if you revved it up at full RPM with no load.

At this point I would try to swap out with known good parts, like a new motor. Most brands of motors will state the following which is not a manufacturer defect but misuse by the user:
1677856957596.png
 
ESC is set to sense the lipo. It beaps on startup the number of cells it detects, so I should have noticed if it was set to 2s (no guarantee I did though)

I pulled the RPM reading and it shows 30563 which should be fine since it can theoretically go to 35000+ at nominal voltage on 4s (14.8V * 2400kV = 35520) so it should be good for even higher (16.8V * 2400kV = 40320) unless I just don't understand the ratio of kV to RPM like I thought I did (again, possible.)

Also, it has no problem spooling up to high RPM when there is no load (holding the car in the air) it only happens under load (ie acceleration) so I'll pull the motor apart, but if that did happen it would have to be a manufacturing issue.


Did some more testing. No stutter at all on 3S. 4S still has the issue, regardless if I use a partially discharged pack (16.6V) or a fresh pack (16.8V). Both packs are brand new Zeee 4S 5200mah 100C packs. Started messing with ESC settings, and no change regardless of if I set the voltage directly or let it auto-detect. I started messing with the punch setting, and was able to determine that is functions fine at punch 7, but the stutter starts at 8. I had forgotten I jacked the punch up to 9...

My read on that is that it's a current issue and the truck just can't pull enough for the initial hit using punch 9 (could be batteries, wires, solder joints, who knows). Am I interpreting that wrong?
Hobbywings website states that the MAX10 140A ESC is only rated to use the 4268 series of G3 motors on 4S (states this combo is for 2WD SCT, buggy, and on-road use only) and you are using the 3665 G3. Since it still runs fine on 3S Id say you're experiencing a sync issue between the ESC and motor since that ESC is not speced to be used with that motor at that voltage. A lot of people call it "cogging" but that isnt technically the correct term for it. Id run it on 3S and call it a day.
 
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Hobbywings website states that the MAX10 140A ESC is only rated to use the 4268 series of G3 motors on 4S (states this combo is for 2WD SCT, buggy, and on-road use only) and you are using the 3665 G3. Since it still runs fine on 3S Id say you're experiencing a sync issue between the ESC and motor since that ESC is not speced to be used with that motor at that voltage. A lot of people call it "cogging" but that isnt technically the correct term for it. Id run it on 3S and call it a day.
They sell the Max-10 140A and 3665 G3 motors as a combo on their website, those ratings are just the maximum recommended size; going below is fine.

They also rate it for 4S, but only with the 2400Kv motor:

Screenshot_20230303_113245_Chrome.jpg

My guess is an overcurrent event damaged something in the ESC...
 
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They sell the Max-10 140A and 3665 G3 motors as a combo on their website, those ratings are just the maximum recommended size; going below is fine.

They also rate it for 4S, but only with the 2400Kv motor:

View attachment 161153
My guess is an overcurrent event damaged something in the ESC...

I run the 2400kv. According to hobbywing it should be 4s safe.

Hmm, thinking that the cogging may be a sensor issue, assuming you re-connected the sensor wire in both the ESC and motor, you might have damaged the sensor board in the motor if you revved it up at full RPM with no load.

At this point I would try to swap out with known good parts, like a new motor. Most brands of motors will state the following which is not a manufacturer defect but misuse by the user:
View attachment 161146

I'm fairly confident I never ran it wide open without the pinion attached. It was very obvious there was an issue when it started, and honestly I don't think I've been able to run the motor wide open on 4s yet at all. Can't keep the wheels down. I'm going to pull the motor later and switch to a smaller pinion (tall gearing is useless when it won't stop parachuting at half throttle, top speed is nice but I'll take increased torque and decreased heat in this case) so when I do that I'll inspect the motor. I'll also reach out to hobbywing to get their thoughts.

So, I took it out and ran it some more today. What I noticed:
-Setting the punch to 7 on the ESC fixed the issue, but as voltage on the battery dropped, the issue returned (right around 4v per cell on my checker is when I noticed.) Could just be confirmation bias, but I think this lends to my belief of a battery/current issue.
-LVCO kicked on and I stopped in about 10 minutes of running, ended with 3.8v per cell with the stock LVCO setting (medium.)
-the fan on the ESC is heat dependent and kicks on around 140*F. After 10 minutes non-stop, the ESC was 160* and the motor was 142*F. Currently don't have a fan on the motor, but I have one I can put on if I decide it needs it. Hopefully dropping the pinion size will keep heat down.

So, that's where I'm at. I have an 18T pinion to put on (once it all cools I can tear it apart) but I may have to modify my servo mount to get anything smaller than that to mesh properly. I don't currently have any sizes from 13T-17T though, so if I want to go any smaller I'll have to order some. (I bought a set a while back, but they sent me 32P instead of M1, so I need new.). I'll throw the 18T on and see where that leaves me.

On the upside, she's crazy fun...
 
If the 4S battery is older, it's possible the cells may have crapped out... I had this happen on a Zeee pack not too long ago where the ESC was shutting off, after replacing every imaginable electronic component, the very last item I replaced was the battery and the problem went away... I now have learned to swap the battery first, doh!
 
If the 4S battery is older, it's possible the cells may have crapped out... I had this happen on a Zeee pack not too long ago where the ESC was shutting off, after replacing every imaginable electronic component, the very last item I replaced was the battery and the problem went away... I now have learned to swap the battery first, doh!
Batteries are brand new, just showed up yesterday. I don't have a charger that checks the IR, but voltage reads good on all cells.

Thanks for all the ideas everyone. I'll keep playing with it to see what I find.
 
They sell the Max-10 140A and 3665 G3 motors as a combo on their website, those ratings are just the maximum recommended size; going below is fine.

They also rate it for 4S, but only with the 2400Kv motor:

View attachment 161153
My guess is an overcurrent event damaged something in the ESC...
They sell that combo because you can run up to 3S on that combo. The ESC itself specifically states that 4S is only for less than 2600Kv and specifically lists the 4268 size. If they meant that as the maximum size then it would have 4268 listed for the 3S rating also. It also specifically says that even the 4268 combo should only be used for for 1/8 scale 2WD SCT, buggy, and on-road use. Its a sync issue, I've had that exact problem before on more than one ESC. This is the problem with buying the bare minimum electronics for what you really want to do. If you wanna run 4S then its always better to buy a 6S capable ESC rather than pushing the limits of a 4S ESC.

Capture.JPG
 
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They sell that combo because you can run up to 3S on that combo. The ESC itself specifically states that 4S is only for less than 2600Kv and specifically lists the 4268 size. If they meant that as the maximum size then it would have that listed for the 3S rating also. It also specifically says that even the 4268 combo should only be used for for 1/8 scale 2WD SCT, buggy, and on-road use. Its a sync issue, I've had that exact problem before on more than one ESC. This is the problem with buying the bare minimum electronics for what you really want to do. If you wanna run 4S then its always better to buy a 6S capable ESC rather than pushing the limits of a 4S ESC.

View attachment 161162
They do list it as compatible with 4S and a 3665 motor ( though only the 2400kv one), as per the screenshot I provided in my previous post, this is directly from their website:

Screenshot_20230303_113245_Chrome.jpg


Can size and KV recommendations are based on the potential current draw. A 2600kv 4268 motor can pull about as many amps as a 4000kv 3665 motor, that's the rationale behind those suggestions. A smaller can or lower KV will have a lower current draw, which is why they say "less than or equal to" a certain value.
 
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They do list it as compatible with 4S and a 3665 motor ( though only the 2400kv one), as per the screenshot I provided in my previous post, this is directly from their website:

View attachment 161163

Can size and KV recommendations are based on the potential current draw. A 2600kv 4268 motor can pull about as many amps as a 4000kv 3665 motor, that's the rationale behind those suggestions. A smaller can or lower KV will have a lower current draw, which is why they say "less than or equal to" a certain value.
Either way, thats what happens when you push electronics to the max. You run in to problems. Either run it on 3S or buy a bigger ESC
 
More power more problems. I'll work through it. You can buy a Corvette and only ever drive it to the grocery store at 25mph too, but where's the fun in that?

I'm getting together with a friend this weekend who has some bigger high-output 4s packs (think he said he has 9000mah 120c packs for his 8s truck) that we can test with to see if the increased output fixes the issue. Additionally I'll be testing with different pinions, and I'm still waiting to hear back from hobbywing about their thoughts.

The challenges are part of the fun of doing your own upgrades. Hell, I had to do some "custom" modifications to servo mounting and linkage to get the motor to fit, and modify the motor mount for the large pinion, and a few other things. That's the fun of it 😊
 
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