Tiny cog issue with Mamba X and HH 2200kv Puller Pro

[air8]

https://www.youtube.com/watch?v=teZc2thtRYs
Here's a short video regarding the teeny bit of "cog" experienced while forward crawling. Not a single issue when backing up. Hope you guys have some ideas.
Thanx.

Version 3.84.00 of the Castle link is installed.

I am experiencing a tiny little cog issue when crawling forward but not backwards. This is only an issue when crawling & forward. After like say...3 to 5 percent throttle it runs great. However when driving in reverse it is absolutely perfect and smooth.

-Traxxas TRX4 Sport
-540 sized Holmes Hobbies Puller Pro 2200kv
-Batteries are 3-cell 4500mAh Proteks and 4200 mAh Venom brands.

The truck is a new build in Feb. 2022. I have around 2-hours of crawling...no trailing yet. The drive train rolls nice and smooth with or without motor mounted.

Using the Castle link, I have tried changing a lot of settings. Even switching modes from Smart Sense to Sensored Only. Then with my radio have tried to dial that slight little cog out of it. I have done the radio calibration numerous times and also tried re-calibration after changing settings with the Castle link. The motor is set in Reverse in the Castle link. I don't experience this with Hobbywing brushless and brushed systems in my other crawlers.

I remember a video by John Holmes describing mosfets loading up when a motor stalls and then suddenly releasing which lets the motor surge the vehicle forward...or something like that. Anyway, looking for suggestions.

[HumboldtEF]

Doesnt seem like cogging to me more like not enough throttle or its high gearing. Notice when it stops the whine from the ESC also stops.

You say the motor is set to reverse, what color is the LED on the Mamba X when going forward? The LED should be green going forward and red in reverse. If you have that backwards you have more Power delivery (mosfets) in reverse than forward. The fact that its better in reverse lines up with this theory but the TRX4 would need a reverse rotation motor so I dont know. Maybe you reversed the throttle on the radio too?

I know that this will happen on some rigs with a bit higher gearing, you can get the rig creeping forward but not at a consistent rate until you give a bit more throttle. A rig geared down a bunch wont usually act this way.

Any error codes coming from the ESC?

[air8]

I think the whine is from the motor...which stops because the vehicle stops. If you listen really close you can hear a buzzing sound, which is the ESC trying to juice the motor. It's difficult to pick up that sound.

The LED on the Mamba is Green when going forward and Red when backing up. The Mamba won't allow calibration if the throttle channel is reversed on the radio. (Page 11 of the Mamba Driver's Guide booklet). That one stumped me for a while one time when I could not get the calibration to take. I had tried swapping the Castle link direction to Forward and change radio channel to Reversed. And then it wouldn't calibrate.

The stock TRX Sport gearing is a 17t pinion with a 39t spur. The top speed was Ludicrous Speed, overshot them by next week (LOL). <<< Any Spaceballs fans here?
Anyway, I changed to a 13t pinion but the issue is still there. I could order an 11t pinion or the 45t spur gear and give that a shot.


I really wish I could just flip the tranny around. The reverse movement is what I see in my other trucks and it is beautifully controlled.

Oh, and no codes on the ESC.

[air8]

And you are right about it not being cogging. It's the ESC buzz when the truck gets loaded up going forward.
I'll see if I can take another video with more focus on the noise.

[air8]

https://youtu.be/R2WcZWQRsVE

When climbing forward, each time the truck stops is where you can notice the "buzz" from the ESC. Yes there is motor whine there also which makes it a bit difficult to pick up on the buzz. But then once the ESC gets enough juice to the motor it lunges a bit or the tires slip.
When climbing backwards there is just complete control, no stoppage, and no wheel spin.

I hope the buzzing from the ESC can be noticed over the frequency of the motor whine.

[HumboldtEF]

What is the start up power set to? I use High. I kind of doubt this is the issue though.

JRH has a video which maybe you've already watched, this is where he mentions start up power:




I just tried to recreate this with a few rigs running Castle ESCs, one with high gearing. What I cant recreate is the ECS whine stopping/cutting out at low throttle. If I give it throttle the wine is constant for me. That makes me think it could be radio related. Are you using the stock traxxas radio?

EDIT: now I can hear yours doesnt cut out either it just gets quieter.

I also checked my TRX4 with a sidewinder 4 and revolver and it has a pretty big deadband but it didnt cut out either.

EDIT: the whine is from the ESC, the motor just acts like a speaker essentially. It just gets louder when the motor spins.

[air8]

That's the video I used to start with. And I did go back through to make sure I didn't miss one little setting. LOL. I wasn't used to some of the settings (I come from 1/10 buggy and 1/8 buggy-truggy racing background). Raced them for almost 10-years.

The radio I have is an Airtronics MT-4. And I suppose I could reset that particular model number to see if it will bind up differently. That's about the only thing I haven't done. The other buggies and crawlers I have on this radio don't exhibit this little stutter at all.

I think tomorrow after work, and changing oil in my truck & car, and playing Lego with the young'uns, and making dinner...I might try resetting the ESC back to Default and clear the radio model number and just start from fresh.

And I could also swap in a Spektrum RX and try one or both of my Spektrum radios.

But thanx for replying.

EDIT: FORGOT, Start power is currently on Medium...I think. I started out at High and have tried changing that in the Castle link several times combined with other settings trying to diagnose and troubleshoot a possible bad combo of settings.

[air8]

So Holmes says he likes "sketchy fast reverse". Haa haahaa haa. I have my reverse set at 50% because I usually correct the vehicle from rolling over backwards well before it can roll backwards. And being at 50% power, when I reverse the truck is super, duper smooth. Might have to play with that regarding forward power....currently down to 80% just to try something to correct the issue.

[air8]

So no luck curing the stall issue at crawl speed. I switched radios, switched back, played with Castle link settings over and over, recalibrate radio(s), etc. Still end up with that little stall a slow speed.
It's usable, but not ideal.

[HumboldtEF]

Did you dial in throttle curve?

You could try a throttle curve with a few points, one down low and then the main curve. The low point would ramp up the curve steeply just long enough to get moving steady and the 2nd would settle into a gradual curve up.

[twade984]

My understanding is that swapping ABC wires on a sensored brushless system = damage to the Esc. Was that done before or after this issue came up?

Besides that, are you absolutely certain there aren’t any mechanical issues with the rig?

And finally, did I see somewhere that the vehicle operates the same in sensorless mode? Perhaps there is an issue related to the sensor or sensor wire.

It’s very confusing that it seems to be fine when operating in reverse. I would like to see what happens if you swap a different motor in. And maybe another Esc, just to rule out some things.


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[Voodoobrew]

Could be a bad/dirty gear tooth. And every time it comes around it hangs.

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[air8]

Originally Posted by HumboldtEF

Did you dial in throttle curve?

You could try a throttle curve with a few points, one down low and then the main curve. The low point would ramp up the curve steeply just long enough to get moving steady and the 2nd would settle into a gradual curve up.

Yea I could keep trying the throttle curve and Expo settings. But haven't found a happy spot just yet.

[air8]

Originally Posted by twade984

My understanding is that swapping ABC wires on a sensored brushless system = damage to the Esc. Was that done before or after this issue came up?

Besides that, are you absolutely certain there aren’t any mechanical issues with the rig?

And finally, did I see somewhere that the vehicle operates the same in sensorless mode? Perhaps there is an issue related to the sensor or sensor wire.

It’s very confusing that it seems to be fine when operating in reverse. I would like to see what happens if you swap a different motor in. And maybe another Esc, just to rule out some things.


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I have tried different pinions and a 2nd spur gear. I do have one other spur I could try.

I Swapped the wires well after trying for hours with the Castle link settings, trying gear mesh adjustments, re-assembling the transmission a few times, playing with radio settings and calibration,, and installing an aluminum motor mount. I was kind of at a loss when I remembered the wire swap thing. But forgot that is regarding sensorless motors.

I have two sensor wires ordered that I will test next weekend.

[air8]

Originally Posted by Voodoobrew

Could be a bad/dirty gear tooth. And every time it comes around it hangs.

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Right. That was the 2nd thing I looked for after gear mesh..
This is a brand new truck that acted this way from the very first time I applied throttle with the truck held up in my hands. After a few hours of trying things I left it and waited for the weekend to come. That weekend I drove it for two hours just crawling on stone and cement paths.
I bought a spur gear and tried again. Then pulled motor and swapped pinion gears a few times. Then on & on & on.

I looked at each tooth and valley of the spurs looking for deformity in the molding/machining.

But no matter where the teeth are in rotation, the ESC/motor will always stall right there when encountering load.

[Voodoobrew]

Remove the pinion and test.

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[suprachrgd82]

I have 7 of the Micro X kits with varying motors (Castle 2280, Castle 2850, HH Revolver 2200, or HH Revolver 2500) and have the same problem with 3 of the more recently purchased Micro X Crawler kits. They are all programmed similarly to the setting recommended by HH in his 3 YouTube ESC programming videos, sans the "sketchy fast reverse".

The 3 in question seem like they are lacking the slow speed power to creep slowly and when they start moving they jump forward. The other 4 run great. I wish I could contribute more to this thread; mostly here to keep up-to-date with any solutions suggested by others...

[air8]

Originally Posted by Voodoobrew

Remove the pinion and test.

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I think I can recreate it with the motor in my hand and using fingers to pinch the pinion. I can get that growl/buzz from the ESC. And while I can stop the motor, it is only for a moment before I feel it pulling on through my grip. LoL.

[air8]

Originally Posted by suprachrgd82

I have 7 of the Micro X kits with varying motors (Castle 2280, Castle 2850, HH Revolver 2200, or HH Revolver 2500) and have the same problem with 3 of the more recently purchased Micro X Crawler kits. They are all programmed similarly to the setting recommended by HH in his 3 YouTube ESC programming videos, sans the "sketchy fast reverse".

The 3 in question seem like they are lacking the slow speed power to creep slowly and when they start moving they jump forward. The other 4 run great. I wish I could contribute more to this thread; mostly here to keep up-to-date with any solutions suggested by others...

Right on. I'm sure we can get it sorted out. And the way that this thing will crawl in reverse is absolutely perfect. In reverse it is exactly what a person would expect. Super fine control and all the power ever needed. But going forward....so close.

[air8]

This past weekend I took the truck out and was able to have a decent time. The little 'lag' is reduced from the first video I posted but it is definately still there. Probably 50% of obstacles I was disappointed on. But then the other 50% I could hear the buzzing start to build and the truck would motor on through. And of course seeing an obstacle coming up I would basically just 'bump' into everything so the ESC wouldn't have to load up. It's just for fun crawling anyway. If it were competition crawling...eh...I'd have to try a different Mamba X, or motor, or just go with a different brand.

I'm not to the point in with crawlers to have spares of the electronics. All my electronics were for 1/8 off-road nitro racing and 1/10 electric off-road racing. Acquiring the torque monster motors\ESC's and the Tsunami strength steering servos is taking quite some time. LOL Plus I'm invested in 1/24 crawlers for the little ones and myself.

I'm going to swap my Hobbywing 1080 and 550 13t Hackmoto Just Climb from my Trail King over to the TRX4 just to prove to myself the drivetrain is ok. The TRX4 drivetrain feel pretty amazing too me. With no motor mounted it is satisfying to just slowly roll the chassis around and enjoy the lack of friction. I'm not sure how else to say that. LOL. I'm was pleasantly surprised by the quality of the TRX4.