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Help with low speed chug/cogging brushless motor/ESC

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Old 05-08-2018, 06:39 PM
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speedknot
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Default Help with low speed chug/cogging brushless motor/ESC

I finally just got a chance to get my new Tacon Valor out and running. I noticed that it was acting like it was missing a gear and stuttering, at low speed, and then took off when I gave it more throttle. It would slowly chug along and then take off when more throttle applied. It was brand new but I still tore it down looking for improper gear mesh or stripped gears, but all looked fine and spinning freely. I took the motor out and applied a bit of pressure to the pinion gear and gave it a little throttle. I think this was the issue. There is considerable stuttering at low throttle but goes away when more throttle applied. I dont have much experience with brushless setups. Is this something to be expected? If not how can I remedy this? I posted a video below. Thanks in advance.

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Old 05-08-2018, 07:26 PM
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Yup, that's what sensorless systems do at low speeds, it is unavoidable. By the way, your videos are unavailable.
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Old 05-08-2018, 07:43 PM
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Thanks for letting me know about the videos. I forgot to publish them. They're up now. So whats the benefit to sensorless systems. I'm ready to go back to brushed.
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Old 05-08-2018, 08:02 PM
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Try lowering the start mode (punch) to level 1 and timing to zero on the esc https://p11.secure.hostingprod.com/@.../25C103-14.pdf and get a 2s lipo.
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Old 05-09-2018, 07:25 AM
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Nah, you don't wanna go back to brushed....brushless is so much better. No wear, no maintenance, more power.... That cogging only happens when minimum throttle is applied. And I mean minimum. And when are you going to use that? Almost never!

Now if you have to apply 50% throttle to get outta that stutter, that's a problem.

Sensorless brushless systems use a "start up routine" to get the rotor turning so that the ESC can determine the rotor position. Once that happens, in milliseconds, it switches to run mode. How smoothly it does that depends on the ESC firmware. Some are better than others. But most these days are excellent. Some other brands, not so much. As long as the stutter doesn't affect the actual running of the car when you're out playing, it shouldn't be a problem.

If you're running a NiMh battery, that could also contribute to the cogging. Get a Lipo pack. Much much better.
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Old 05-09-2018, 07:11 PM
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Originally Posted by speedknot View Post
Thanks for letting me know about the videos. I forgot to publish them. They're up now. So whats the benefit to sensorless systems. I'm ready to go back to brushed.
Nothing is really great about sensorless. What they do, is at low speeds, kind of "guess" where the rotor is in the can and just give power to the coil. In a sensored system, a set of Hall effect sensors (magnet sensors) can tell where the rotor is, and can make it turn at a low speed because it is able to track it.

Don't go brushed!! Rob is 100% right.
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Old 05-09-2018, 07:22 PM
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Thanks for the info guys. It does help to understand the mechanics of it. I had reset the ESC to factory defaults. Then I incrementally lowered the timing to "0". That didn't help. I hooked up the motor in my car(no load) to an ESC in my sons other car and the cogging almost went away. The more I read up on this, the more I find other people having the same issue with this ESC/Motor combo. The majority replace the ESC and its fine. I'll try throwing a smaller pinion in there to see if that helps. If not, on to looking for a better ESC.
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Old 05-10-2018, 07:11 AM
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I just looked that truck up and saw a yt video. That is a fairly small truck. Smaller than my HoBao Hyper TT but a little bigger than a Dromida 4.18. I'd look at a Hobbywing 35 Amp B2 combo brushless system. It's a great little system for under $100. Oh shoot, looks like they've been discontinued by Hobbywing. But I found one here new for $67!!
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Old 02-28-2019, 05:24 PM
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Capacitors could be worn out.

I called Castle on this and they came up with odd excuses first as well, once I told them it worked great and instant amazing burn outs when first buolt they said it's most likly worn out Capacitors in the ESC.
My sensorless 2200 and Castle Mamba has InsAne! power when I first drove, then sat in storage for many years, and now it is stuttering. I have since changed capacitors but have not yet check the ESC settings or the XPS Lipo 6S 4000.
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Old 03-01-2019, 07:06 AM
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Is the motor and ESC wired directly? Or do you have bullet connectors between the two? If the latter, check those connectors and maybe use a little dielectric grease on them. A loose or high-resistance connector will cause the motor to stutter.
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