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rich_morris

ESC affected by Steering Servo??

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Hi, I have just finished putting together my son's TT-02 with him, and cone across a problem.

The car came with a TBLE-04S ESC. Got it all connected up, and when using the steering, the motor moved sporadically, like there is interference between the servo and ESC.

Tried a separate receiver and servo, with the same effect.

Swapped the ESC for another NIB TBLE-02s, and after setting it up to reverse, that worked fine, and is now the ESC staying in that car.

So, is there an issue with my ESC, or is there a setting I need to change? I've another kit in build, which will also have a TBLE-04. Is this a known problem?

For the third car I now need to fix the ESC or buy a replacement. I see hobbywing are recommended for a budget...

Rich

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Last Wednesday I had the exact same problem but it was a late 80's Futaba ESC coupled with an early 90's AM-75 receiver of the same well loved brand. So I am commenting here to be if there is anybody able to help with ideas or experience on how to fix the problem.

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What's the radio and what's the servo?

Most common reason for this is a combination of a servo that demands a high current and an ESC that can't supply it, or a receiver that can't cope with the momentary voltage drop.

Also if you are running a brushed motor there is potential for them to cause interference although it really only happened with old AM radios. Sealed can motors normally have capacitors built in to them already but you can add more.

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Savox servos are quite famous for it, known as 'Brown out' ,as they are power hungry, which starts to give issues using a cheaper esc (lower amp capable BEC), and sucks all the power away from the receiver.

Setting the end points on the steering helps, as the servo isn't trying to push past its dead stop.

Fitted a 'glitch buster' to one of my cars , which is just a capacitor plugged into a spare esc port. That acts like a little storage battery, and provides a little extra ,if the volts drop.

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This was tried with:

Futaba Servo s-U300

Core servo CR493.

Unbranded S3003

With combinations of Flysky, Core and Futaba receivers and transmitter. All 2.4ghz

The second TBLE 04 seems mostly ok, although I did notice one small glitch.

To be clear, with the car sat still, turning the steering causes the motor to glitch momentarily. Wiggle the steering and the motor continues to glitch constantly.

No issue at all with TBLE02 with same gear.

All with Tamiya Torque tuned motors.

Off to local hobby store so will see if there's a cheap fix. A £18 ESC won't break the bank...

Rich

 

 

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I have the same exact problem with the same ESC, Flysky Rx and an El-cheapo S3003 servo. Never had the same problem with the servo/Rx combo, so seems to be an ESC issue. I managed to trim out the self running problem last night, after reseting high points, but had not got a chance to check if it sticks and works. Getting sick of the 04 ESC, they seem to cause no end of problems. 

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My SkyRC ESC programmation card has a servo testing feature.

As per what I saw with the servo tester, most (if not all) the digital servo I had are above 2A consumption when moving. Some are even reaching 3A+. The Tamiya ESC specs indicates 1.5A max consumption for both ESC+Server. The reality seems to indicate it is way above this, so I tries anyway. If I figure out issues, I add a glitch buster in the equation and never had any issues (TBLE-02S - not figured any différence yet with the TBLE-04S, but having just one in use it is difficult to make my mind about limitation at this stage).

 

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22 minutes ago, silvertriple said:

As per what I saw with the servo tester, most (if not all) the digital servo I had are above 2A consumption when moving. Some are even reaching 3A+. 

OP also had the same problem (which I also experienced with the same setup) with an El-cheapo S3003 and that one will definitely not draw 2A or more. 

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1 minute ago, alvinlwh said:

OP also had the same problem (which I also experienced with the same setup) with an El-cheapo S3003 and that one will definitely not draw 2A or more. 

The thing is that until you know what is the consumption of the servo, you can just do assumption. I decided to test those systematically, as the power cut power on power cut power on fried a couple of RX with gyro included: since the time I put a glitch buster systematically for those conditions, I never happened again (gyro will make the steering servo going crazy, so there is chance you get the glitch very frequently)... That being said, It's rare I need the glitch buster even with the consumption above 2A with the TBLE02S...

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Oh boy, I remember this nightmare : ) I run a funny mit of no Limit ESC, 2x12T brushed motor and a strong, modern servo. That took me a good while to make it all work with no glitches or brown-outs.

 

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"Glitch Buster" - fixes a lot of little things. 

isn't a S3003 a Futaba servo w/bushings - No bearings. Would be a Tamiya also.

I think Tamiya had issues with some TBLE's, not sure of the # 02, 04, or 05?

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Hi, I've now fitted 2 TBLE-04S to 2 different rc cars, and had this issue with both. I seem to get chatter on the steering and forward movement on the throttle when using the steering. Both cars fitted with spectrum reciever and different servos. Problem seems to go away when I move throttle stick back a couple of mm, but can't trim it out. This also enables reverse. Never had this problem on 02s.

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6 hours ago, Crouchie said:

Hi, I've now fitted 2 TBLE-04S to 2 different rc cars, and had this issue with both. I seem to get chatter on the steering and forward movement on the throttle when using the steering. Both cars fitted with spectrum reciever and different servos. Problem seems to go away when I move throttle stick back a couple of mm, but can't trim it out. This also enables reverse. Never had this problem on 02s.

Yours is like the 5th or so I had seen with this problem. After extensive testing, I found that this is a 2 part problem. First question is, what are your servos? This ESC provides painfully weak BEC power that can lead to brownouts. I mostly solved mine with an UBEC. But the second problem is I do find that the 04 do not hold neutral too well, especially evident when returning to neutral from reverse. At least it no longer try to run away but just "twitches". 

I do not have 02 to test against but the 104 that I do have never had such problems. (I just double checked as I am currently working on that car right now) 

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6 hours ago, Crouchie said:

 I seem to get chatter on the steering and forward movement on the throttle when using the steering. 

Like this? 

After installing UBEC. 

 

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Yep, exactly like that! So the 04 basically has a crummy bec? I'm assuming the UBEC you quoted is a universal stand alone bec unit? Never seen one, but sounds like what I need. I've ordered a couple of those glitch eliminator capacitor things as well to try. Thanks for the info, at first I thought I'd got faulty servos. 👍🏻

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1 hour ago, Crouchie said:

Yep, exactly like that! So the 04 basically has a crummy bec? I'm assuming the UBEC you quoted is a universal stand alone bec unit? Never seen one, but sounds like what I need. I've ordered a couple of those glitch eliminator capacitor things as well to try. Thanks for the info, at first I thought I'd got faulty servos. 👍🏻

The 04 (and 02 if IIRC) have a 1.5A BEC. A standard basic servo draws 1.something A, and then the RX draws 0.3A, putting it right at or just over the limit. I tested a 9kg servo that caused the most problems and it draws over 3A, more than double! 

The  UBEC I used, I solder it to the battery connector on the ESC plug. IT WILL ALWAYS BE ON powering the RX and servo even when the ESC switch is off until I do a mod to include a switch. An alternative is a short adaptor between the battery and ESC with the UBEC, this will allow portability between cars, but I decided to just hardwire in a unit for each of my older/weaker ESCs. Here is the info about how to go about it. Also, I only got a 3/6A one, which is borderline for my 9kg servo. I have since got some 6 and 8A ones. 

 

Glitch blaster is the first thing I tried. First one I made out of 4700uf capacitor (double what is normally sold) and it didn't help at all. Then I tried a monster double one (4x what is commonly sold), and it still didn't work! 

udozH7o.jpg

It seems that the 04 is so bad that is unusable without a UBEC and even with one, it still have some problems with neutral. 

There is probably nothing wrong with your servo or radio like my case. I had tested mine with a signal tester and they works fine even though someone (on my thread) was quick to jump the gun on blaming my "cheap beginner gear" while ignoring the readings I posted. Even if I switched to the the most expensive radio gear, the problem will still be there as it is not the radio! 

You had not (unless I missed it?) told me your servo yet? But anyway, what I saw in other forum is the ballpark figure for servos is 1A per 3-4kg. This seems to be true in my tests with a "standard" 4kg drawing 1.something A and a 9kg drawing 3.2A.

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Hi all, thanks for those inputs and advice.

The Servo I was using is a Core RC 4012. I also got the problem with a Futaba U300.

For update, a second car with same ESC and servo has thus problem occasionally.

But now has another problem where the Servo sometimes seems to lag the steering input when racing. I've not been able to replicate on the bench.

Could that also be related to the power output of the ESC?

Rich

 

 

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4 hours ago, rich_morris said:

The Servo I was using is a Core RC 4012. I also got the problem with a Futaba U300.

They are both relatively "standard" basic 4kg servos, so around 1.2A. You are right on the borderline of what the 04's BEC can support, the Futaba probably will be worse as it is slightly hider at 4.5kg. If you have a higher powered servo, like a 9kg one, you will get a runway car/car gone mad situation. 

The sluggish servos can be partly due to the BEC not delivering enough power to turn them fast, causing the RX to go off for a moment or any other combination. Try your glitch blaster and if that don't work (didn't work for me), try an UBEC. 

Final solution to this problem if all else don't work, replace the 04 with a 1060 and be done with it. If you are running brushless, you are in for an expensive ESC replacement then. 

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