Granite Twin Granite BLX throttle cut out issue.

ssands85

Well-Known Member
Messages
113
Reaction score
72
Location
MN
Arrma RC's
  1. Granite
I haven’t ever used it, but I would think you could make something like that work
 

RC_N00B

Active Member
Messages
12
Reaction score
1
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

Well-Known Member
Messages
99
Reaction score
166
Location
United Kingdom
Arrma RC's
  1. BigRock 4x4
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

Active Member
Messages
12
Reaction score
1
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

Well-Known Member
Build Thread Contributor
Messages
132
Reaction score
134
Location
Woking, UK
Arrma RC's
  1. BigRock 4x4
  2. Kraton EXB
  3. Notorious
  4. Senton 3s
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

Active Member
Messages
12
Reaction score
1
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

Well-Known Member
Build Thread Contributor
Messages
132
Reaction score
134
Location
Woking, UK
Arrma RC's
  1. BigRock 4x4
  2. Kraton EXB
  3. Notorious
  4. Senton 3s
, 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 ;-)
 
Last edited:
Messages
1,528
Reaction score
1,355
Location
Yacolt, Washington
Arrma RC's
  1. Senton 3s
  2. Typhon 3s
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.(y)🤣
 
Top