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-   -   Steering issue (https://www.rctech.net/forum/radio-electronics/1123416-steering-issue.html)

JSHuiting 04-29-2024 10:53 AM

Steering issue
 
Whenever i give full throttle my servo steers sharply to the right and then goes back to neutral all in the blink of an eye.

I checked the wiring and all seems good, i measured the servo's signal which i believe was 5,66V full to the right, 5,77 neutral and 5,88 to the left which all seem good.
When steering is in neutral and i give full throttle the servo signal seems to dip to 5,75, but this may in reality be even lower since my multimeter may not be fast enough.

The servo is a Power HD S15, receiver Sanwa RX-482, and the ESC is a ORCA BP1001
This problem occured with my old receiver as well which was a Ruddog RR482

Roelof 04-29-2024 03:08 PM

The servo signal is no voltage, it is a PWM pulse you can only measure with an oscilloscope or a special PWM meter.

I would advise to play with the EPA setting of your full throttle. If the servo get blocked at full throttle then a huge current can flow making a small voltage drop with which probably the failsafe is activated causing the servo going to center.

gigaplex 04-29-2024 04:56 PM


Originally Posted by Roelof (Post 16096940)
The servo signal is no voltage, it is a PWM pulse you can only measure with an oscilloscope or a special PWM meter.

Agreed


Originally Posted by Roelof (Post 16096940)
I would advise to play with the EPA setting of your full throttle. If the servo get blocked at full throttle then a huge current can flow making a small voltage drop with which probably the failsafe is activated causing the servo going to center.

They're using an ESC, not a throttle servo.

Roelof 04-29-2024 11:19 PM


Originally Posted by gigaplex (Post 16096952)
They're using an ESC, not a throttle servo.

Oeps.....
Yet, it still looks like a glitch or a voltage drop. Things to try:
- place the receiver further away from the ESC
- try a glitch buster.
- try an external BEC

JSHuiting 04-30-2024 12:10 AM

Thanks, i'll try moving the receiver first, and order a glitch buster just incase.
I did use the same layout on my TB Evo which had this issue aswell..

But what could be causing the interference anyway, i initially thought the ESC was pulling too much current.

Roelof 04-30-2024 01:12 AM

An ESC is creating a high power and high frequency PWM signal creating a magnetic field. Not directly in the 2.4GHz range but more in the range of internal data signals. Any high impedance data signal can still be influenced by external electro-magnetic fields.

Another thing I have heard. Do you have a 3 wire RC4 transponder put in the battery slot of the receiver? That seems to cause issues with a Sanwa receiver.

JSHuiting 04-30-2024 02:41 AM

Interesting, but no not on this one yet, my A800R has a RC4 Pro but that one isn't giving me issues.
The rest of the electronics are identical aswell.

billdelong 04-30-2024 07:27 AM

Check your wiring for loose connections, the following issue was solved after I re-seated the servo connector back into the Rx:

https://www.youtube.com/watch?v=frkmoMhQ5AQ

The following issue was solved after fixed the HV servo harness:
https://www.youtube.com/watch?v=LneubAZ5oX0&t=35s

Solution here:
https://www.rcgroups.com/forums/show...0#post40061288

Also note that it can be anything from an incompatible servo with your ESC and myriad of other gremlins if the glitch buster doesn't solve your issue after checking for loose connections

Roelof 04-30-2024 07:51 AM


Originally Posted by billdelong (Post 16097079)
Also note that it can be anything from an incompatible servo with your ESC

Strange words.... Some servo's can be power hungry and so they can draw currents beyond the limits of the ESC in the BEC. But lets say a 40kg strong servo in a simple 1/10 tourer will never draw high currents unless the endpoints are not adjusted well.

Beside that, he has the issue with giving throttle, so no active servo.

billdelong 04-30-2024 09:00 AM


Originally Posted by Roelof (Post 16097088)
Strange words.... Some servo's can be power hungry and so they can draw currents beyond the limits of the ESC in the BEC. But lets say a 40kg strong servo in a simple 1/10 tourer will never draw high currents unless the endpoints are not adjusted well.


Beside that, he has the issue with giving throttle, so no active servo.



It's been many years since I've seen incompatibilities but they were mostly around analog servos getting jittery from the digital signals from the ESC. It was a common problem at the track in my area and I had a list of known combinations that did not work between brands of ESC/Servo that I tracked on the URC forums, but that info was lost after URC shut down many years ago. Glitch buster did not solve the issue, new digital servo from a different brand fixed it ;)

Roelof 04-30-2024 10:03 AM

It has nothing to do with compatible, there is no compatibility list to find. Basically such issues come from a bad or poor design and most of the time from a switching BEC

billdelong 04-30-2024 03:46 PM


Originally Posted by Roelof (Post 16097123)
It has nothing to do with compatible, there is no compatibility list to find. Basically such issues come from a bad or poor design and most of the time from a switching BEC

I can assure there are compatibility lists out there and it was very painful to manage when servos were still analog, the following is an example from Sanwa that compares their Rx's but it translates back to incompatible analog servos:
https://www.sanwa-denshi.com/rc/comm...e%20180704.pdf

The gist is you need to run new with new and old with old, don't mix match an old servo with a newer ESC and visa versa

gigaplex 04-30-2024 05:24 PM


Originally Posted by Roelof (Post 16097123)
It has nothing to do with compatible, there is no compatibility list to find. Basically such issues come from a bad or poor design and most of the time from a switching BEC

...Which can cause incompatibilities despite there not being documentation around compatibility.

Roelof 04-30-2024 11:34 PM


Originally Posted by billdelong (Post 16097193)
I can assure there are compatibility lists out there and it was very painful to manage when servos were still analog, the following is an example from Sanwa that compares their Rx's but it translates back to incompatible analog servos:
https://www.sanwa-denshi.com/rc/comm...e%20180704.pdf

The gist is you need to run new with new and old with old, don't mix match an old servo with a newer ESC and visa versa

That is not the issue. Analog servo's are just made to work with the 50~60 Hz framerate, any faster setting like digital, SR, SSR, SXR etc. The same counts for normal digital servo's that do not support super response modes. In most ways you can set the channel to "analog". Still that is not the issue in this topic.


Originally Posted by gigaplex (Post 16097222)
...Which can cause incompatibilities despite there not being documentation around compatibility.

I would not say incompatible because high chance with others it can work without issues. A tolerance thing, design revision, wrong component choice or an alternative component choice with a production serie and lets not forget the huge amount of fake components that hit the market in Corona time. And I know because I work at an electronic production company facing this on a daily base. All issues that can not directly named as an incompatibility.

gigaplex 05-01-2024 12:02 AM


Originally Posted by Roelof (Post 16097304)
I would not say incompatible because high chance with others it can work without issues. A tolerance thing, design revision, wrong component choice or an alternative component choice with a production serie and lets not forget the huge amount of fake components that hit the market in Corona time. And I know because I work at an electronic production company facing this on a daily base. All issues that can not directly named as an incompatibility.

In other words, an incompatibility. Tolerances etc can lead to unintended compatibility issues.


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