lALXl

Hi,
I have an HPI Trophy Truggy Flux, and I'm running a Savox 0251 servo with 8 LEDs on the body. I'm having an issue where I turn slowly and the servo is good till like 99% of wheel turn (99% is when the full lock occurs), but when I get the wheel on the transmitter to 100% of the turn, the servo backs out to like 25% of max turn. Also I'm not getting any blinks on the receiver and the ESC doesn't reset.
Do I have to buy a BEC, glitch buster, or just sell this freaking piece of sh*t and buy an Axial Yeti Score/Traxxas Slash?.
I won't ever buy anything from HPI again. They are a really bad brand nowadays. And the Trophy Truggy/Buggy are probably the worst in their lineup, because of the lack of optional parts.

flyinwalenda

My Feedback: (5)

The original servo was not digital...what happened to the original servo?

The Savox is digital and digital servos typically require more power than analog ones.

Is there any binding or restrictions in the steering/.suspension ?

Did you properly adjust the travel of the servo on the transmitter ? If not that will stress and burn out any servo.

If there is no binding, and the travel adjustment is correct then you may need more power(not voltage) than the esc's bec can provide to operate that servo.

lALXl

Oh and by the way I'm unfortunately still using the standard Tf-11 transmitter and RF-11 receiver.
I have the original servo and this situation doesn't occur with it.
Even if I get my ST D/R knob to lowest (turned all the way to the left), the issue will still occur just in a smaller scale and less visible. So there are no restrictions in steering and the issue still happens.
By adjusting the travel of the servo on the transmitter you mean EPA for separate left and right?
There is servo whining noise all the time, no matter what I do with it. When I turn it is whining and when I want to re-center it it whines, so I don't know what the problem is.

flyinwalenda

My Feedback: (5)

Digital servos always whine .

I'd say that servo needs more power than the ESC can provide through the receiver. Either install a separate receiver battery pack (disable the esc bec first) or install a Castle BEC set to 6v wired directly to the main batteries and power the servo directly from the bec.

Or put the stock servo back in .

lALXl

Thanks for the help.
I might just swap the savox for the original one and save it for my next build project.

lALXl

EDIT!!!: I swapped the Savox servo for the original one, and it's still doing it. It didn't happen before with the stock servo.
However I noticed something very weird. If the receiver's antenna isn't pointed straight onto the transmitter, some weird glitches begin to happen, for example losing some power for a few seconds, then losing the power completely and after a few seconds gaining max power, and the cycle continues. The weird glitches include the servo backing out at 100% turn signal.
I noticed that my 4S battery is very slightly bulged outwards on the top and bottom (I don't remember if it was like that or not). I checked the temps after run and it seems to only be a bit warm. Nothing special, just a bit warmer than my freezed hand (in Poland we have winter now) sooo... Should I be worried about my battery or should I replace the transmitter and receiver (as that may be the main problem)?

flyinwalenda

My Feedback: (5)

Did the truck roll-over and damage the receiver antenna. The business end is the last 2" and if that gets ground/cut off you will have limited range and issues with servos.

Lipo's swell from either sitting for weeks/months at full charge, running the vehicle past LVC, or using the wrong charger or incorrect settings. You need a cell checker or a charger with a display to see the voltages of each cell in order to determine if the pack is OK.

lALXl

Ok, so I rolled over the truck but the antenna seems fine.
The LiPo battery was sitting for weeks because I didn't have time to run the truck, but it was at half-charge just as you should store LiPos, I don't think that I've been running the truck after LVC. LiPo cutoff is when a tuck loses a bit of max power, then stops and then going back to max power for a few seconds? If so then I ran it 3 times only to get back to my garage which is about 20 meters. Is that enough to destroy a LiPo?

flyinwalenda

My Feedback: (5)

It is enough to make it puff up. LVC exists for a reason. It monitors the battery and cuts power to the motor when it senses the battery is at it's safest lowest voltage. The vehicle then looses power and slows down and eventually stops. At this point the driver should walk to the vehicle pick it up and bring it back.
Too many drivers let the truck sit for a minute or more and then limp the vehicle in to where they are. The battery will recover a bit to where the LVC will turn off and allow the motor to run again however the battery has nothing let to give and begins to heat up and the cells swell up and the battery gets damaged.

lALXl

Ok, thanks man, I really appreciate your help. So that means that I have to get a new battery and the problems should go away, doesn't it?

RustyUs

LVC differs from ESC to ESC. Having it set low, e.g. 3.0v/cell, might not be such a good idea if running a pack that is known to have a bad health issues (high internal resistance). If you have a LiPo pack with cells that hold their balance well, then lower LVC settings won't be an issue. I would not recommend a low setting on the LVC unless you know the ESC and your packs well. Normally, I would have packs come off the track reading 3.4v/cell after the LVC completely shuts down. Now I just set all my ESC's LVC to 3.4v/cell, if option is available. Voltage from my packs will usually read 3.7v/cell after a LVC triggering/shut down of ESC, and the pack sits for 10 seconds.

Possible that OP has run through some water?

flyinwalenda

My Feedback: (5)

I don't know.
You only have one set of batteries?
You need to troubleshoot something. Either test the batteries or try a known good set.
Or get a good 6 volt receiver pack, plug it into the receiver (don't plug the main batteries in) and see if the servo issue still exists.
As stated, you may have got the receiver or ESC wet and damaged it.

lALXl

Yes I ran it in snow but the battery was waterproofed by me

lALXl

Everything was very carefully waterproofed before running in water. However before I waterproofed it I ran it a couple of times on a damp asphalt/grass. Would this affect it? I haven't ran the truck in water/puddles.

flyinwalenda

My Feedback: (5)

The only way to determine if or what is damaged is to perform some troubleshooting and elimination of suspected issues.
If I didn't have a battery tester or a good charger than can display cell voltages and/or internal resistance then I would get or borrow a 6 volt receiver battery pack and plug it into the receiver to test the servo problem. If the servo works then the suspects are either the ESC or the batteries. If the problem still exists then I would suspect the receiver.

lALXl

I believe the issues come from the battery. It doesn't want to balance the 4th cell. When I balance it the 3 first cells are at 3.9v while the 4th one is at around 4.15. I think that the 4th cell swelled up. In near days I'm going to try and ask my local hobbyshop if they will let me test the truck on a battery that they (maybe) have lying around and then I will post an edit, and probably the end of this thread. If they have it in stock I'm going to buy a 6v receiver battery pack to fully test everything.
No matter what thanks for the good help, and I will talk to you soon.

lALXl

So I tested everything fully and the issue was coming from the battery. Thanks for the help everyone.

tntpooof

adjust end points and then get a ubec the bec on esc cant supply enough amps for servo..