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Old 06-09-2011, 10:40 AM   #1
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Default Servo sometimes veers to the left when under full constant throttle

I have noticed something odd with my rig. When I get to a relatively flat area on a trail that has some small pebbles, bumps, etc., and I am driving at full throttle (it has a 45T motor so it isn't faster than a walking pace) it sometimes seems as though the servo starts steering left and stays there(despite my input with the steering wheel on the controller) until I completely let off the throttle. After I let off the throttle, it's back to normal. I can get this weirdness to occur fairly often if I try to make it happen. I don't know what is causing it. Any ideas as to what it could be?

UPDATE: I took an up-close video of my truck doing this so you all can witness it and maybe know what to do. In this video the truck does it on the 3rd, 4th, and 5th burst of throttle. During the entire video I am not touching the steering on the controller at all.


Last edited by BadRockNoCookie; 05-31-2012 at 12:02 PM. Reason: update
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Old 06-09-2011, 10:55 AM   #2
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Default

No idea, try a different radio, don't touch the rx and connections though. Just bind a different radio to it and see if it still happens
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Old 05-31-2012, 12:00 PM   #3
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Default Re: Servo sometimes veers to the left when under full constant throttle

I updated this with a video that shows the problem in action.
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Old 05-31-2012, 07:15 PM   #4
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Default Re: Servo sometimes veers to the left when under full constant throttle

Do you have a bec?
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Old 05-31-2012, 07:42 PM   #5
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Default Re: Servo sometimes veers to the left when under full constant throttle

Quote:
Originally Posted by losikid View Post
Do you have a bec?
Looks like a CC 10A BEC in the picture.

I had a big reply going earlier until I REALLY looked at the pic, then deleted my reply.
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Old 05-31-2012, 09:15 PM   #6
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Default Re: Servo sometimes veers to the left when under full constant throttle

I see it now on my computer...the blue blends on my phone

What servo is it?
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Old 06-01-2012, 11:28 AM   #7
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Default Re: Servo sometimes veers to the left when under full constant throttle

Quote:
Originally Posted by losikid View Post
I see it now on my computer...the blue blends on my phone

What servo is it?
Yes, it's got a CC BEC on it that is set to 6V. The servo is a Hitec 5645MG : HS-5645MG - Hitec RCD
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Old 06-01-2012, 04:33 PM   #8
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Default Re: Servo sometimes veers to the left when under full constant throttle

what happens when your going backwards?
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Old 06-01-2012, 07:34 PM   #9
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Default Re: Servo sometimes veers to the left when under full constant throttle

I had the same problem in my Wraith. Changed every single component except the ESC without fixing it. Finally swapped out the Novak Havoc 3s controller for a MM Pro and solved it. I cannot explain why. Your not running a Novak ESC by chance are you?

Mine wouldn't do it in reverse, only forward.

I too was using a Castle BEC.
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Old 06-02-2012, 10:21 AM   #10
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Default Re: Servo sometimes veers to the left when under full constant throttle

Had the same problem, look at steering glitch thread in electronics. It was a ground issue for me.
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Old 06-04-2012, 09:47 AM   #11
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Default Re: Servo sometimes veers to the left when under full constant throttle

Quote:
Originally Posted by losikid View Post
what happens when your going backwards?
The same thing. It happens more often when going backwards though.
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Old 06-04-2012, 09:48 AM   #12
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Default Re: Servo sometimes veers to the left when under full constant throttle

Quote:
Originally Posted by meatmonkey View Post
I had the same problem in my Wraith. Changed every single component except the ESC without fixing it. Finally swapped out the Novak Havoc 3s controller for a MM Pro and solved it. I cannot explain why. Your not running a Novak ESC by chance are you?

Mine wouldn't do it in reverse, only forward.

I too was using a Castle BEC.
I am running a Tekin FXR.
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Old 06-04-2012, 09:57 AM   #13
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Default Re: Servo sometimes veers to the left when under full constant throttle

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Originally Posted by Mike5025 View Post
Had the same problem, look at steering glitch thread in electronics. It was a ground issue for me.
I'll check that out.
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Old 06-04-2012, 10:02 AM   #14
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Default Re: Servo sometimes veers to the left when under full constant throttle

are any of your motor/servo wires overlapping?
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Old 06-05-2012, 02:53 PM   #15
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Default Re: Servo sometimes veers to the left when under full constant throttle

Quote:
Originally Posted by ROLANDROCKSHOP View Post
are any of your motor/servo wires overlapping?
On one side of the frame, the positive and negative wires from the output of the BEC run underneath the motor wires that are coming from the ESC and going to the motor. They are in a clip together.

On a side note, last night I was able to get the truck to stop doing the glitch by increasing the reverse throttle trim to 100%(I normal keep the reverse trim at 76%), running it for about 3 minutes, then bringing it back down to 76%. Don't know why that helped, but it seemed to. Seems like if it was having a wiring problem that the glitch would still be happening.

Also, after checking my wiring last night, I remembered that the BEC is already grounded to the RX because when I first put the truck together and wired the BEC straight to the servo, the servo freaked out constantly. So I hooked the BEC up to the RX so that the BEC is giving power to the RX and the servo and the servo stopped freaking out. The only thing the ESC is powering is itself and the motor.
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Old 06-05-2012, 06:50 PM   #16
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Default Re: Servo sometimes veers to the left when under full constant throttle

Quote:
Originally Posted by BadRockNoCookie View Post
Also, after checking my wiring last night, I remembered that the BEC is already grounded to the RX because when I first put the truck together and wired the BEC straight to the servo, the servo freaked out constantly. So I hooked the BEC up to the RX so that the BEC is giving power to the RX and the servo and the servo stopped freaking out. The only thing the ESC is powering is itself and the motor.
Did you remove the red wire from the ESC to RX connection & insulate it (since you're running the external BEC to the RX)?? You should NEVER run 2 red power sources to the RX, you may fry something or have issues.
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Old 06-06-2012, 08:02 AM   #17
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Default Re: Servo sometimes veers to the left when under full constant throttle

Quote:
Originally Posted by Charlie-III View Post
Did you remove the red wire from the ESC to RX connection & insulate it (since you're running the external BEC to the RX)?? You should NEVER run 2 red power sources to the RX, you may fry something or have issues.
I cut the ESC's red wire so that only the signal wire and the ground are going to the RX. I then folded the red wire over and heatshrunk it .
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Old 06-06-2012, 09:46 AM   #18
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Default Re: Servo sometimes veers to the left when under full constant throttle

That's a tough one!

Are you running an AM radio system by chance?
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Old 06-06-2012, 03:21 PM   #19
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Default Re: Servo sometimes veers to the left when under full constant throttle

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Originally Posted by heyok View Post
That's a tough one!

Are you running an AM radio system by chance?
I keep leaving out details, lol. I am running a Futaba 3PM-X 2.4 radio.
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Old 06-06-2012, 03:24 PM   #20
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Default Re: Servo sometimes veers to the left when under full constant throttle

Quote:
Originally Posted by BadRockNoCookie View Post
I keep leaving out details, lol. I am running a Futaba 3PM-X 2.4 radio.
That's okay, we will drag those details out of you!

So much for the AM noise theory, but it might be good to make sure all your connections are good.

Do you have another servo you might be able to try in place of your steering servo? Maybe it has an intermittent connection inside and is causing it to glitch.
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