Mojave Issue with our 'new to us' Mojave 6s

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MatusK

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Hi,

this is just my second thread and I am not 100% sure I am posting it in the correct sub-forum. But let me start.

I bought for my daughter a barely used Mojave 6s that had no tuning to its parts (apart from some foam pads for the body mounts and a fan on the motor cooler. The car indeed looked good inside and outside, so I am willing to believe it was not trashed. The seller has a very good reputation too.

So I got a pair of brand new Ace Gets 3s 6800 mAh batteries and Ace Gents charger, charged the batteries, put them in, turned the car on in the proper order - and it all worked as it should. I would get those 6 + 1 (higher pitched) beeps and the car would run normally.

So we took it out to get the very first experience, drew the car slowly (throttle at 50%) and basically tried to get the hang of it. No bashing, no jumps, no crazy nothing. Mostly on loose surfaces and asphalt and some wet short evening grass here and there. It was fun to watch my daughter learn her first steps with an RC car. After about 15 minutes I asked whether I can try the car out, she handed me the transmitter - and the car would not move. Nothing. It sounded like it was off (no buzzing of the fans), but then it started to 'buzz' again, but it would not normally react to the commands it would drive front and back, but it would not steer.

I opened the car, turned everything off and back on - the same. Throttle worked the steering not. After a few more attempts to turn the whole thing on and off there was not even a throttle. Great. Took the car home to have a look at it under proper lights.

There was more dirt inside than I would have naively expected, so I cleaned the body shell separately with a hose and brushed the internals as well as I could (I am still awaiting delivery of some cleaning stuff). There was no water inside the car, but it was all damp. I would not assume that to be a problem with this model.

I opened the box where the receiver sits to be able to observe it. and then tried 2 different ways to turn the car off:

1) (the standard way)

- Turn the transmitter on
- Connect the battery
- Turn the ESC on
--> The receiver LED turns on, but the rest of the car does nothing, only the both fans (EXC and motor) run. No reaction to the commands from the transmitter, but attempting to 'turn right' would increase the RPMs of the fan on the motor. Strange.


2) (The wrong way)
- Receiver off
- Connect the battery
- Turn the ESC on
--> The car would go through the standard 'beeping', but with no movement to the steering. During this the ESC would produce a few red LED blinks Both fans would turn on too.
- Turn the transmitter on
--> The receiver LED would immediately turn on. But there was no reaction from the car to any of the commands. Only when trying to turn to the right, the fan on the motor would increase the RPMs

I checked the batteries - both are at around 4.1V per cell - after about 15 minutes of a rather laid-back driving sounds fine to me.

To be honest, I have no clue what to do. I would very much appreciate any kind of advice or help.

I will attach a few photos in a few moments and if necessary I can make a short video about how the car behaves.

D967898E-F22D-487F-9AE7-4F3BC968561D.jpeg


FA398460-CA21-4228-9F4D-8A181387047A.jpeg


0CE3B371-EE25-470D-8B22-E2BFD820DAF7.jpeg


8F4D716D-4F02-48E4-B08E-2C0E09E8ED24.jpeg


E34026DA-83D1-43D1-80D8-3E1CF7D204B8.jpeg
 
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Hi,

this is just my second thread and I am not 100% sure I am posting it in the correct sub-forum. But let me start.

I bought for my daughter a barely used Mojave 6s that had no tuning to its parts (apart from some foam pads for the body mounts and a fan on the motor cooler. The car indeed looked good inside and outside, so I am willing to believe it was not trashed. The seller has a very good reputation too.

So I got a pair of brand new Ace Gets 3s 6800 mAh batteries and Ace Gents charger, charged the batteries, put them in, turned the car on in the proper order - and it all worked as it should. I would get those 6 + 1 (higher pitched) beeps and the car would run normally.

So we took it out to get the very first experience, drew the car slowly (throttle at 50%) and basically tried to get the hang of it. No bashing, no jumps, no crazy nothing. Mostly on loose surfaces and asphalt and some wet short evening grass here and there. It was fun to watch my daughter learn her first steps with an RC car. After about 15 minutes I asked whether I can try the car out, she handed me the transmitter - and the car would not move. Nothing. It sounded like it was off (no buzzing of the fans), but then it started to 'buzz' again, but it would not normally react to the commands it would drive front and back, but it would not steer.

I opened the car, turned everything off and back on - the same. Throttle worked the steering not. After a few more attempts to turn the whole thing on and off there was not even a throttle. Great. Took the car home to have a look at it under proper lights.

There was more dirt inside than I would have naively expected, so I cleaned the body shell separately with a hose and brushed the internals as well as I could (I am still awaiting delivery of some cleaning stuff). There was no water inside the car, but it was all damp. I would not assume that to be a problem with this model.

I opened the box where the receiver sits to be able to observe it. and then tried 2 different ways to turn the car off:

1) (the standard way)

- Turn the transmitter on
- Connect the battery
- Turn the ESC on
--> The receiver LED turns on, but the rest of the car does nothing, only the both fans (EXC and motor) run. No reaction to the commands from the transmitter, but attempting to 'turn right' would increase the RPMs of the fan on the motor. Strange.


2) (The wrong way)
- Receiver off
- Connect the battery
- Turn the ESC on
--> The car would go through the standard 'beeping', but with no movement to the steering. During this the ESC would produce a few red LED blinks Both fans would turn on too.
- Turn the transmitter on
--> The receiver LED would immediately turn on. But there was no reaction from the car to any of the commands. Only when trying to turn to the right, the fan on the motor would increase the RPMs

I checked the batteries - both are at around 4.1V per cell - after about 15 minutes of a rather laid-back driving sounds fine to me.

To be honest, I have no clue what to do. I would very much appreciate any kind of advice or help.

I will attach a few photos in a few moments and if necessary I can make a short video about how the car behaves.
You may have to try to rebind your tx & rx
 
Thank you - I will try that out and report back.

P.S. Seeing those photos so large - the car looks terrifyingly dirty. The I will definitely do a much more proper cleaning (also want to take down the wheels and check the diffs in the next few days). And the fenders are on their way but to ship anything from UK to EU is a major PITA ...
 
OK, so I tried to do exactly as the manual says on the bottom half of the page 12:
- connect the batteries
- turn on the transmitter
- push & hold the button A (set button) AND pus the button B (on/off switch) and wait until the ESC starts to blink red, the fans are running at low speed)
--> The ESC never starts to blink red
--> I tried the same procedure WITHOUT turning on the transmitter - and then then the ESC did start to blink red (and fans run at higher speed) and make noises. But as soon as I turn on the transmitter the blinking disappears and the fans drop in speed.

Hmmm

EDIT:
OK, after a LOT of trying around I was able to run this page No. 12 procedure as described and now the transmitter does connect with the ESC car normally again. But the servo does not react and I am starting to wonder whether it died ...
 
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@MatusK ,

That lame S652 Spektrum RTR servo probably went south on you and this is also known to fry the ESC. They suck. One of the first thngs to change out anyway. I don't like RTR servos at all. They cheap out on these to keep the Price point low.
Hopefully the ESC was not shorted out by the Spektrum Steering servo in the procss, and is still ok.

>>> First, I would disconnect the Steering servo plug at the Receiver and see if the ESC starts up and you have throttle. If so, the servo is definitely to blame here. If not, then perhaps the ESC is also bricked. This can happen out of nowhere, no one's fault, just Poor Spektrum Servo/ESC. Again, it's this S652 Servo that will usually burn out the Firma ESC while in the process of failing.
This is a common problem , even with a fairly new rig, Some have this happen first time out the box.
Replace the ESC under the Free 2 year warranty. Just Not the Servo. Don't even take a free Spektrum servo as a replacement. Same will happen again.
Buy an Upgrade brand servo . Even like a DS3235 35 kg ....Amazon servo at $34. is perfect. Why I use them in all my 6s rigs including my Mojave. New out the box I toss the RTR servos. They are underpowered anyway. A stronger servo will make the rig much easier to drive.

>>> Consider buying the ScorchedRC Mojave Inner body fenders. This will keep out the dirt and pebbles and rocks very well. Most of us use these.. An important upgrade. The Mojave is a Closed wheeled body, so all the dirt kicks up well inside the chassis. A problem with all these SCT bodies.
 
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Try swapping the ESC's cable to the steering port and see if your ESC responds with your transmitter steering input.

And do it with the servo's cable in the throttle port. See if your servo responds with throttle input.

Just DON'T do both at the same time.

This way you can test the receiver Ports AND the individual devices ,to eliminate any doubts.

Let us know what you find out.


**********

And your interior doesn't look all that bad compared to our ripping sessions.. Definitely seen Much worse.

Yours is actually quite clean.
 
@MatusK ,

That lame S652 Spektrum RTR servo probably went south on you and this is also known to fry the ESC. They suck. One of the first thngs to change out anyway. I don't like RTR servos at all. They cheap out on these to keep the Price point low.
Hopefully the ESC was not shorted out by the Spektrum Steering servo in the procss, and is still ok.

>>> First, I would disconnect the Steering servo plug at the Receiver and see if the ESC starts up and you have throttle. If so, the servo is definitely to blame here. If not, then perhaps the ESC is also bricked. This can happen out of nowhere, no one's fault, just Poor Spektrum Servo/ESC. Again, it's this S652 Servo that will usually burn out the Firma ESC while in the process of failing.
This is a common problem , even with a fairly new rig, Some have this happen first time out the box.
Replace the ESC under the Free 2 year warranty. Just Not the Servo. Don't even take a free Spektrum servo as a replacement. Same will happen again.
Buy an Upgrade brand servo . Even like a DS3235 35 kg ....Amazon servo at $34. is perfect. Why I use them in all my 6s rigs including my Mojave. New out the box I toss the RTR servos. They are underpowered anyway. A stronger servo will make the rig much easier to drive.

>>> Consider buying the ScorchedRC Mojave Inner body fenders. This will keep out the dirt and pebbles and rocks very well. Most of us use these.. An important upgrade. The Mojave is a Closed wheeled body, so all the dirt kicks up well inside the chassis. A problem with all these SCT bodies.

Thank you! Yes, the ESC seems fine (wheels are turning), the servo is probably dead. Oh well, could be worse. Will order new one this weekend.

The body fenders from ScorchedRC have been shipped on 18th of November and the last update was on 20th. There are a few things I would like to say about that, but rather won't. Honestly - I can't imagine running in anything but bone-dry conditions with the stock body. It is basically a dirt collector. I may consider putting some 'net' ovet the fans as even after that short, innocent drive there was dust and little stones in there.

Try swapping the ESC's cable to the steering port and see if your ESC responds with your transmitter steering input.

And do it with the servo's cable in the throttle port. See if your servo responds with throttle input.

Just DON'T do both at the same time.

This way you can test the receiver Ports AND the individual devices ,to eliminate any doubts.

Let us know what you find out.


**********

And your interior doesn't look all that bad compared to our ripping sessions.. Definitely seen Much worse.

Yours is actually quite clean.
Great idea, thanks! I could get this work with the throttle cables at the position of the steering - so the wheels would turn if I would try to drive 'left' (but not 'right'. But the when I plugged the steering cables to a throttle slot in the receiver the ESC was not happy and was blinking red.

Still to me this is another hint that I need to swap the servo.
 
Thank you! Yes, the ESC seems fine (wheels are turning), the servo is probably dead. Oh well, could be worse. Will order new one this weekend.

The body fenders from ScorchedRC have been shipped on 18th of November and the last update was on 20th. There are a few things I would like to say about that, but rather won't. Honestly - I can't imagine running in anything but bone-dry conditions with the stock body. It is basically a dirt collector. I may consider putting some 'net' ovet the fans as even after that short, innocent drive there was dust and little stones in there.


Great idea, thanks! I could get this work with the throttle cables at the position of the steering - so the wheels would turn if I would try to drive 'left' (but not 'right'. But the when I plugged the steering cables to a throttle slot in the receiver the ESC was not happy and was blinking red.

Still to me this is another hint that I need to swap the servo.
Yeah the Stocker servo is horrible. Don't know why Arrma/HH insists on still using them. They are extremely flawed cheap garbage. Many an ESC has fried because of them. You would think that Spektrum/HH would step up their game with something so obviously wrong. Give's them a bad name IMHO.
>>The ScorcedRC fenders will absolutely keeps things 85% + cleaner depending where you run your Mojave. Just fine dust if anything collects. Not tragic.
ScorchedRC can be a bear to deal with orders at times. Be patient. But the fenders are a must have. You will see. Just take your time installing them. I believe there is a video for this as well.
I never ever run my rigs in the wet stuff. ESC's , fans ,motors and electrics are just not WP like they claim to be. Been there. Mud and dirt is fine.
Even just Grass Dew that came out of nowhere while bashing at Dusk got the best of my RTR ESC once. The Dew was just enough to cause an ESC fire. The whole chassis got wet from dew in minutes. Crap happens.
Enjoy.:cool:
 
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So I am officially on a hunt for a servo that:
1) is ideally a "drop-in" replacement
2) does its job the way it should
3) is available in Germany / Europe (the Chines one mentioned above will take 4+ weeks to arrive)
 
Yeah in the EU product availaibilty is so different.
Hang in there.
I just recommend a 35 kg servo whatever you get.(y)
And one with 7.4v capability (HV servo). Your RTR Firma 150 ESC can hande 7.4V BEC. By adjusting the ESC parameter settings. Per the Firma ESC manual. By default, the BEC volts are set to 6.0 volts sometimes. Manual states default is 7.4v. Double check yours to make sure. Good to have the Firma Programmer to adjust your ESC settings more easily/quickly. Less chance for errors.

https://www.arrma-rc.com/on/demandw...ab12/Manuals/SPMXSE1150-Programming_Chart.pdf
 
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@MatusK ,

That lame S652 Spektrum RTR servo probably went south on you and this is also known to fry the ESC. They suck. One of the first thngs to change out anyway. I don't like RTR servos at all. They cheap out on these to keep the Price point low.
Hopefully the ESC was not shorted out by the Spektrum Steering servo in the procss, and is still ok.

>>> First, I would disconnect the Steering servo plug at the Receiver and see if the ESC starts up and you have throttle. If so, the servo is definitely to blame here. If not, then perhaps the ESC is also bricked. This can happen out of nowhere, no one's fault, just Poor Spektrum Servo/ESC. Again, it's this S652 Servo that will usually burn out the Firma ESC while in the process of failing.
This is a common problem , even with a fairly new rig, Some have this happen first time out the box.
Replace the ESC under the Free 2 year warranty. Just Not the Servo. Don't even take a free Spektrum servo as a replacement. Same will happen again.
Buy an Upgrade brand servo . Even like a DS3235 35 kg ....Amazon servo at $34. is perfect. Why I use them in all my 6s rigs including my Mojave. New out the box I toss the RTR servos. They are underpowered anyway. A stronger servo will make the rig much easier to drive.

>>> Consider buying the ScorchedRC Mojave Inner body fenders. This will keep out the dirt and pebbles and rocks very well. Most of us use these.. An important upgrade. The Mojave is a Closed wheeled body, so all the dirt kicks up well inside the chassis. A problem with all these SCT bodies.
100% for the aftermarket fenders.... Very much worth every penny....

Agree about the servos... The only good thing about the factory servos is, whenever they give out, a better one can be had for less $$ than a stock replacement
 
So I found one of these cheap no-name servos with quick shipping and ordered one. But I am seriously starting to think about ProModeler (though ordering from Europe will send the price through the roof, not sure I am ready to take the plunge quite yet)
 
@MatusK ,

That lame S652 Spektrum RTR servo probably went south on you and this is also known to fry the ESC. They suck. One of the first thngs to change out anyway. I don't like RTR servos at all. They cheap out on these to keep the Price point low.
Hopefully the ESC was not shorted out by the Spektrum Steering servo in the procss, and is still ok.

>>> First, I would disconnect the Steering servo plug at the Receiver and see if the ESC starts up and you have throttle. If so, the servo is definitely to blame here. If not, then perhaps the ESC is also bricked. This can happen out of nowhere, no one's fault, just Poor Spektrum Servo/ESC. Again, it's this S652 Servo that will usually burn out the Firma ESC while in the process of failing.
This is a common problem , even with a fairly new rig, Some have this happen first time out the box.
Replace the ESC under the Free 2 year warranty. Just Not the Servo. Don't even take a free Spektrum servo as a replacement. Same will happen again.
Buy an Upgrade brand servo . Even like a DS3235 35 kg ....Amazon servo at $34. is perfect. Why I use them in all my 6s rigs including my Mojave. New out the box I toss the RTR servos. They are underpowered anyway. A stronger servo will make the rig much easier to drive.

>>> Consider buying the ScorchedRC Mojave Inner body fenders. This will keep out the dirt and pebbles and rocks very well. Most of us use these.. An important upgrade. The Mojave is a Closed wheeled body, so all the dirt kicks up well inside the chassis. A problem with all these SCT bodies.
Was totally going to say servo too . Specktrum servo strikes again same thing has happened to me like 3 times
 
So I found one of these cheap no-name servos with quick shipping and ordered one. But I am seriously starting to think about ProModeler (though ordering from Europe will send the price through the roof, not sure I am ready to take the plunge quite yet)
I been through all the expensive name brands early in my RC days. Futaba, Hitec, Savox . I rather use chinese cheaper variants for just simple bashing. Because all servos break and are consumables at some point. Especially sooner with hard bashing.
However my very next Expensive servo will be a Promodeler.(y)
Just that I don't race anymore. But can appreciate a quality servo. PM uses Japanese motors and potentiometers and are handbuilt very well. I can't see how any other Name brand servo can compete. PM servos are used by the Military for Drones. That says something.
 
But I am seriously starting to think about ProModeler…
I’m in a similar situation, just had the stock S652 servo go bad after about a month. HH was very quick to send out a replacement, but now I think it may be better to upgrade the servo and keep S652 as a spare…
One thing I read on the ProModeler site, they do not recommend their servos be used with BEC, but suggest a separate LiPo just for servo. I’ve reached out to John at ProModeler for more insight into this and also for a servo recommendation. I will post any useful details… Maybe some here have experience with this?
 
I’m in a similar situation, just had the stock S652 servo go bad after about a month. HH was very quick to send out a replacement, but now I think it may be better to upgrade the servo and keep S652 as a spare…
One thing I read on the ProModeler site, they do not recommend their servos be used with BEC, but suggest a separate LiPo just for servo. I’ve reached out to John at ProModeler for more insight into this and also for a servo recommendation. I will post any useful details… Maybe some here have experience with this?
I am looking forward to hear what you learn from John, thank you in advance :)
 
Bear in mind that ProModeler is primarily an Air RC servo company. Their claim to fame with Mission critical servos and the Expert Air RC crowd. Any servo will always run best with a dedicated Battery. (separate lipo Plugged directly into the Rx. to power the Servo channels ) And this serves as a Failsafe for Air RC use, if the ESC fails during mid flight. Always Maintaining your Surface Controls ( flaps and rudder control) to Glide land safely. (servos always remaining powered)
For Surface RC bashng, ESC-BEC powered servos are just fine. All Surface ESC's these days are BEC equipped for this reason. And a simpler chassis layout results. Less bloated and lighter.
With most high end Air RC ESC's there is usually never any integrated BEC anyway. Batteries are needed. There is no Battery Elimination Circuit.
Promodeler is more focused on this approach.
 
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I am looking forward to hear what you learn from John, thank you in advance :)
Got a reply back from him and we’re still emailing about a specific servo suggestion, but he is continuing to suggest using a separate battery to power the ProModeler servos. Here is email reply about it:

“And honestly, you're far better off power the control circuit with a dedicated battery instead of a BEC circuit.”

And from the website, he gives this reasoning:

“operating voltage is 4.8-8.4V, but optimal performance is obtained with a 2S LiPo instead of a BEC. This is because LiPos deliver the required current without voltage spikes, noise, or otherwise adversely affecting the delicate avionics (25C or better is recommended).”

I’ll let you know if any more details come from our email chat, but since he continues to press the issue of dedicated battery power (even for non-air use), I am starting to lose interest.

But… 😊 during a visit to LHS today I did see a ProTek PTK-130T and the specs look good. (See pic)

@ARRMArcfanboy4life suggested I also look at AGFRC, Perfect Pass, Reefs RC servos. So I will begin researching these as well.

2BEE1DE7-0D69-49F2-8BC9-01944954F9EA.png
 
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