Glitching as hell, even with a CC Bec

[MaFoDes]

Ok. So yes, i did a forum search before posting this. But all searches come down to "install a Bec". Well, i have that.

What's the problem?
On my COD build i have a Hobbywing sensored brushless combo 17,5T. A High voltage CYS servo (@7,5V), a Radiolink RX/TX and a CC pro bec set to 7,5 Volts plugged in the 3rd channel.

During the maiden run, couple of weeks back, i noticed the motor stalled. Sometimes not reacting to the controller at all.
O.k. i thought. Must be a binding issue. By accident (my bad) i pushed the switch in the rx too hard and killed the Rx lol...

While waiting for the new Rx i took the Rx/Tx from the GMade. A stock Axial controller combo and installed that. I checked it before installing.

When i connected the battery the car "Shook, liked a shock. But it worked. Well, it worked for 5 seconds. Damn, i thought...
So i took the servo and Brushless combo from my Losi NC and installed that set. Just to eliminate all the options.

But still, the motor (from the Losi and it performs flawless there) keep on glitching. I bypassed the CC Bec to eliminate that from the circuit and it still glitches. Like driving a few feet. Then stopping. Then driving again but it "shocks". A few feet good and so on.
I used several different Lipo's, but all with the same result.
Also i disconnected all the wires for the lights, winch etc. But no difference.

Weird story, i know. But any thoughts?
So with totally different electronics it does the same thing in the rig.

[JohnRobHolmes]

Be sure your pinion grub screw isn't hitting and there is no binding in your drivetrain. It sounds like you have swapped out every single electronic, so there might be something floating around inside your axle or transmission that is occasionally jamming in a gear.

[QuesoDelDiablo]

^^What he said, and:

7.5V is a lot for most Rx's, in my limited experience most can only handle 6V. Are you sure the ones you're using can handle the voltage? Is it possible the Rx is throttling your BEC?


I hate hunting electrical gremlins, good luck to you!

[HDMM]

Sounds like a RX/TX problem to me possibly. I had weird glitching problems and compatibility problems with some other electronics back when I used to run Spektrum in some of our rigs. The Spektrum stuff was the problem.

[MaFoDes]

Thanks for thinking with me guys. I absolutely appreciate it.
For this moment, i think i am on to something. I just can't explain it.
Please, bare with me:

After my post i took another TX/Rx combo. Still glitches. Checked for binding in the driveline, but that was as smooth as, as.. As.. Well, very smooth.

Then i took the Nobrainer Bec i once bought on this wonderfull forum. However, it was too late to go out to my "testing grounds". So i went today. Damn... She still glitched.
But then i noticed something. I happened with the precision of a Swiss clock everytime i drove her up or down a steep hill. Now, to be honost the Dragbrake (set to 100%) does not work all too good on this Hobbywing 10BL60 sensored. So i had to use the throttle to keep her in place. Bit forward while going up, bit backwards when going down. And exactly there is when it happens!

For some strange reason she looses control there.
I went home, took the program card and started fiddling with the settings.

For those familiar with the Hobbywing settings, i had these settings:

1 - Running mode: Forward and reverse (option 3)
2 - Dragbrake Force: 100% (option
5 - Brake force: 100% (option 4)
7 - Initial brake force: 40% (option 4)

So i switched to:
Running mode: Forward/reverse with brake
Initial Drag brake force: Drag brake force

Now, for now that seems to work. It ain't ideal. But i have to work with it, as i promised some guys and my sponsor A'tees to take her to a comp' upcoming sunday.
Especially the running mode setting i don't like. But ok...

Is it very dangerous to state that this Esc does not do all to well for Crawlers? As 2 identical Esc's, with 2 identical motors do the exact same thing under the exact same circumstance....

Conclusion. I need a better Esc

[Olle P]

Seems like MaFoDes is on to something, but my thoughts reading about these problems went in another direction:

Antenna placement!
* The actual antenna is just the outermost ~3cm of the antenna wire (assuming a 2.4GHz system).
* That bit should be mounted straight (for best reception) and preferably some distance up and away from the other electronics (to prevent EM interference from these).
* Chassis parts made of metal or carbon fibre located between the transmitter and antenna can act as a shield, preventing proper signals from reaching the Rx.

[MaFoDes]

Well Olle. Normally i would agree with you 100%...
However. Just to try something different, i installed a brushed setup last night.
Just came back from my "testing grounds". A terrain, forest like with some nasty inclines. The receiver stayed where it was as during the first testing and where the glitching happened. Now with the brushed setup, she performed like a dream. So, back to brushed it is......

I have my first comp on sunday and i felt like i was just messing and screwing with a setup that does not work. Don't wanna take that risk!

[Dwill]

Did you by chance check the sensor wire to be sure...

A> it's fully plugged in on both the motor and the ESC
B> The sensor wire itself isn't bad

I can tell you I had cogging issues with my ROC 412 and RSX ESC for a time after I completed the build of my Wrangler G6. I checked the sensor wire (or thought I did) to be sure it was plugged in, spent a LOT of time programming and re-programming my RSX. Went through every bit of the drive train looking for anything binding or rubbing etc. I programmed a bunch of different throttle curves into TX (Airtronics M12), re-bound the TX/RX several times...

No matter what the cogging would not go away.

Then one day I was at the track racing my go fast 1/8 Tekno buggy and there was a Tekin team guy in the shop. I talked to him about what was going on with my G6.

Gotta be the sensor wire either bad or not plugged all the way in he says, I swore to him that I had checked that it was plugged in multiple time and that I had tried two different sensor wire. It couldn't possibly be the sensor wire...

I had the G6 with me, short story made into a long post....

The guys looks at me motor and ESC for about 10 seconds, says "yep, the sensor wire isn't plugged in all the way on the ESC" he shows me where its out on one side such a small amount I could barely tell, and never noticed it myself.

He took some tweezers from my tool box, pushed on the edges of the sensor plug... and... haven't had a single cog since...

[MaFoDes]

Mmm...
Yes, i think there is nothing wrong with the cable. I even switched to another one. But.... Those things are so damned flimsy that i do not dare to press hard on 'm.

In the upcoming weeks, after the first comps, i will build the combo in another SCX10 and start using that as a testing rig. The COD for now, needs to do work.

[lzysmrf]

just a thought, did you make sure that the red wire from the ESC is removed from the receiver? i had to make some mods to the ECS on mine, put it back in, and forgot to remove the wire. i got frustrating results until i realized what i did.

again, just a thought

[MaFoDes]

Originally Posted by lzysmrf

just a thought, did you make sure that the red wire from the ESC is removed from the receiver? i had to make some mods to the ECS on mine, put it back in, and forgot to remove the wire. i got frustrating results until i realized what i did.

again, just a thought

And it's a good thought indeed. I did that. I also bypassed the Bec (unplugged it) and used the internal Bec.

[Olle P]

Originally Posted by MaFoDes

Well Olle. Normally i would agree with you 100%...

Perhaps I wasn't clear enough... my antenna rant was not aimed at your specific problem, since you'd already got a long way to solve it.

It's meant for other, future, readers of this thread that have problems featuring the same (or similar) symptoms to the ones you had.

[MaFoDes]

I read you Olle P. The antenna can be a true factor.
Thanks for contributing!