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So today I took the Blackfoot out for the first time since the nearly 55mph speed run I did the other day and now it stutters and stumbles when I give it throttle and then just goes wide open and flips backwards. I tried to plug the program card in and change the settings and see if that helps but all it will do is blink the blue "work state" light and nothing else. I also swapped out the receiver but that didn't change anything. I even tried different batteries and she still acted the same. I don't know if that last speed run trashed the esc or the motor or what's going on. It's a surpass hobby esc and 5900kv motor. I ordered another identical motor/esc combo today. Hopefully the new set up will last longer than the last (which I'm sending back). I only did a few bench tests with my nimh battery, maybe two dozen test runs with two 2s batteries until I switched to the 3s and made about a dozen speed runs until the last one which was the fastest. The 3s is still nearly fully charged...

I'm not having much confidence in these Amazon brushless speed control/esc combos...

I ran all Novak ESCs and Trinity motors back in the day...

 

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I can't really pinpoint it over the Internet, but I'm curious about a few things:

  1. What are the cell counts, capacities, and discharge ratings (both continuous and burst) for your battery packs?  If you're running 20-30C discharge rate packs, they might see their voltage dip too much which might cause LiPo protection cutouts and/or ESC resets to occur, which might cause throttle calibration to be wonky when it starts running again, causing it to run away from you.
  2. What is the brand and model number of the TX and RXs you are using?  I've looked at some receiver outputs with an oscilloscope in the past, and not all receivers put out the same amplitude of signal to the servos and ESC.  If the ESC is looking for a higher amplitude signal and the receiver is just on the hair edge of acceptable, you might see some glitching or weirdness too.
  3. Is this a sensored motor system?  Any reason to believe the sensor wire has an intermittent connection?
  4. How does it behave on the bench with basically no load on the wheels?  Does it still act flaky there?  If it doesn't misbehave on the bench then I might start thinking about batteries.  If it does misbehave, then I'd start thinking about receiver and ESC compatibility, or maybe a defective ESC.

Sometimes they cut corners in the design of the less expensive stuff, and it shows.  My Flysky Tx and RXs are mostly good, but they can glitch a little and the deadband in the middle of the throttle travel is touchy.  My Futaba equipment seems flawless in comparison.  And I'm still using Novak brushless setups, some Castle Creations, and some SkyRC Toro stuff.  The SkyRC equipment isn't quite as nice as the older Novak and CC.

Good luck, I hope you can sort it out.

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Just a side thought but I've been pretty wary of the cheap esc and motors and receivers that everyone seems to be raving about.  The saying buy once, cry once applies to a broad spectrum of products especially electronics. 

Hope you get it figured out either way bro. 

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I'd be tempted to check all the soldering joints, I've melted solder in the past (a rubbish soldering job I got on a Reedy motor right enough), as it's free to do, but as the programme card won't work, it doesn't look to point towards that.

If you're planning on doing alot of speed runs,a decent motor and esc is a must imo. I went for castle, and they've been faultless (Although I have blown a 5700kv motor and max pro esc, but 5s on a 3s limit motor, and only blew as I'd over heated it doing multiple runs, so....). The motors have double the limit at 100k rpm (the cheaper motors are 50k limit?)  

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If it's a sensered ESC check the cable is not loose. Dried solder can sometimes give you issues.

I had a brushless ESC that use to judder and it was just one loose connection on the orange wire.

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So I replaced the motor, esc and receiver and it's still doing it! It's only stumbling under load. WTH?!?!?!?!?!?!

On 3/6/2021 at 11:52 PM, speedy_w_beans said:

I can't really pinpoint it over the Internet, but I'm curious about a few things:

  1. What are the cell counts, capacities, and discharge ratings (both continuous and burst) for your battery packs?  If you're running 20-30C discharge rate packs, they might see their voltage dip too much which might cause LiPo protection cutouts and/or ESC resets to occur, which might cause throttle calibration to be wonky when it starts running again, causing it to run away from you.
  2. What is the brand and model number of the TX and RXs you are using?  I've looked at some receiver outputs with an oscilloscope in the past, and not all receivers put out the same amplitude of signal to the servos and ESC.  If the ESC is looking for a higher amplitude signal and the receiver is just on the hair edge of acceptable, you might see some glitching or weirdness too.
  3. Is this a sensored motor system?  Any reason to believe the sensor wire has an intermittent connection?
  4. How does it behave on the bench with basically no load on the wheels?  Does it still act flaky there?  If it doesn't misbehave on the bench then I might start thinking about batteries.  If it does misbehave, then I'd start thinking about receiver and ESC compatibility, or maybe a defective ESC.

Sometimes they cut corners in the design of the less expensive stuff, and it shows.  My Flysky Tx and RXs are mostly good, but they can glitch a little and the deadband in the middle of the throttle travel is touchy.  My Futaba equipment seems flawless in comparison.  And I'm still using Novak brushless setups, some Castle Creations, and some SkyRC Toro stuff.  The SkyRC equipment isn't quite as nice as the older Novak and CC.

Good luck, I hope you can sort it out.

1. It's a 3s, 60c. The 2s batteries are all 50c, the nimh is a 7 cell.

2.flysky fsgt2 radio and fsgr3e receivers.

3. sensorless, since I swapped all the electronics I doubt it's a loose wire at this point...lol...

4. It's only does this under load. Like if I hold the tires down on the bench, at lower than 10% throttle it glitches then tries to rip the top of my workbench when I give it more throttle...

 

It wasn't doing this before the speed runs, I drove it around inside the house chasing the cats with it, now it just glitches until it gets more throttle then it seems to go wide open and flips backwards. Unless it's the radio doing it but wouldn't my other car act up too??? I'm stumped...

I'm going to rebind it tomorrow when I get up. It's late now and I need sleep...

 

Maybe it's the radio batteries getting low???

 

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This seems similar to a recent problem I had where selecting full throttle, it would stutter and then accelerate and full reverse would again stutter but not even accelerate, just keep stuttering.

One at a time I changed the components but even with a different ESC (ran set-up each time), receiver/transmitter (including re-binding), battery, it was still happening. I didn't change the motor or steering servo.

This was driving me nuts and seemed to be defying logic.  In the end, it seems I had 2 faulty esc's, with exactly the same fault. I had been running a more powerful motor so assume I damaged them, even when testing. I tried a completely different ESC and it ran for a 2 hour bash yesterday with no issues.

I hope you fix your problem.  Although mine seems fixed I'm not totally convinced yet.

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Just try check the gears just incase there's something in there? 

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