Granite Twin Granite BLX throttle cut out issue.

[ssands85]

I haven’t ever used it, but I would think you could make something like that work

 

[RC_N00B]

Update: Arrma sent me a replacement servo. It's an S6170. Not really sure if this is considered an upgraded part, considering it's not the same one that came stock with the Granites. However, I also FINALLY got the Arrma 25T servo saver, so I can now go shopping for a couple cheap 20kg upgrade servos and just swap out the stock junk. Still no update on the throttle cut out, but now that I'll be able to have all the trucks running again, I'll look further into the issue.

 

[Boomer]

Update: Arrma sent me a replacement servo. It's an S6170. Not really sure if this is considered an upgraded part, considering it's not the same one that came stock with the Granites. However, I also FINALLY got the Arrma 25T servo saver, so I can now go shopping for a couple cheap 20kg upgrade servos and just swap out the stock junk. Still no update on the throttle cut out, but now that I'll be able to have all the trucks running again, I'll look further into the issue.

Out of interest, what run time were you getting before you had the throttle issues? Also, for future reference, the Traxxas 3744 servo saver is 25t and works perfectly. Only costs a few pounds.

 

[RC_N00B]

Out of interest, what run time were you getting before you had the throttle issues? Also, for future reference, the Traxxas 3744 servo saver is 25t and works perfectly. Only costs a few pounds.

Damn, wish I knew that 2 months ago. I want to say the run time before throttle cut out was anywhere from 5 - 15 minutes.

 

[Paul777]

Just re-read the original post and noticed you're running on 2S batteries - my son's big rock does the same on 2S especially when cold, or if it gets stuck in the undergrowth and you pull the trigger hard. I tried 3 different BLX100 ESCs with the same result - the surge in amps just pulls the voltage down too much on 2S.

I did find that when I (as opposed to my son) ran on 2S it was ok - I tended to be driving harder/faster but more linearly on the throttle, which increases battery temp and in turn reduces the voltage drop, also and not jabbing at the throttle meant I didn't get the sudden voltage drops.

Solution is to run on 3S which results in lower amps for the same power. If the speed is too much for the kids turn the transmitter to 50 or 75% mode. My 8 year old has progressed and now runs his Big Rock on full 3S power a lot of the time, but generally starts each session with it turned down.

 

[RC_N00B]

Just re-read the original post and noticed you're running on 2S batteries - my son's big rock does the same on 2S especially when cold, or if it gets stuck in the undergrowth and you pull the trigger hard. I tried 3 different BLX100 ESCs with the same result - the surge in amps just pulls the voltage down too much on 2S.

I did find that when I (as opposed to my son) ran on 2S it was ok - I tended to be driving harder/faster but more linearly on the throttle, which increases battery temp and in turn reduces the voltage drop, also and not jabbing at the throttle meant I didn't get the sudden voltage drops.

Solution is to run on 3S which results in lower amps for the same power. If the speed is too much for the kids turn the transmitter to 50 or 75% mode. My 8 year old has progressed and now runs his Big Rock on full 3S power a lot of the time, but generally starts each session with it turned down.

I think this is exactly the problem. They like to lightly tap the throttle and this is when it cuts out. The trucks have never lost throttle when I drive them. We'll deal with it for now, they're not ready for 3S quite yet.

 

[Paul777]

, they're not ready for 3S quite yet.

3S with 50% or 75% set on the transmitter depending on terrain behaves pretty much like 2S but without the fails from what I've found. Assuming they can be trusted not do flick the switch to 100% themselves ;-)

 

[Ginglehopper]

3S with 50% or 75% set on the transmitter depending on terrain behaves pretty much like 2S but without the fails from what I've found. Assuming they can be trusted not do flick the switch to 100% themselves ;-)

If you don't show them the throttle limiter and tell them not to mess with the settings, or it will mess up the car, i'm pretty sure they won't.

 

[RC_N00B]

I finally got around to replacing the servo with a 20kg I found on Amazon. Got through it with minimal fuss. Turned it on. NO JOY! WTF!!! Maybe it wasn't a bad servo afterall. But what could it be, a bad transmitter?

I finally got around to replacing the servo with a 20kg I found on Amazon. Got through it with minimal fuss. Turned it on. NO JOY! WTF!!! Maybe it wasn't a bad servo afterall. But what could it be, a bad transmitter?

Nevermind, I'm retarded. I had the servo plugged into the wrong slot.

 

[RC_N00B]

It's working now, but the steering is backwards. Not sure how that happened. Good thing the TX has a reverse switch.

 

[Velodromed]

It's working now, but the steering is backwards. Not sure how that happened. Good thing the TX has a reverse switch.

I think you reversed the plug on that one? Black wire to the left on the receiver. But yeah, it is nice that the remotes have a reverse switch.

 

[Paul777]

It's working now, but the steering is backwards. Not sure how that happened. Good thing the TX has a reverse switch.

Nothing you did as such, some servos just seem to work backwards to others - as you have found you just flip the switch. I have found that Arrma servos seem to operate opposite to the others I've used.

 

[*420+3RC*]

I had to switch my sterring reverse also. 25kg dss servo

 

[Wes13]

I had to switch my sterring reverse also. 25kg dss servo

Yeah same here...

 

[Ruzty1311]

I had to switch my sterring reverse also. 25kg dss servo

Same....here.

 

[Velodromed]

Nothing you did as such, some servos just seem to work backwards to others - as you have found you just flip the switch. I have found that Arrma servos seem to operate opposite to the others I've used.

I just went out and looked at two of my voltages and the servos are reversed on those as well, I just forgot I had hit the switch’s awhile back. Both of them have those 20kg dss servos. My granite has a 25 KG version and it’s not reversed so yeah I see what you say…hit or miss.