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Viper Marine 25 keeps servo reversing on its own

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  • Viper Marine 25 keeps servo reversing on its own

    I have two Viper Marine 25 in my sub. One for propulsion, one on water pump. They both manage to flip over to opposites eg forward starts working as reverse. Blow becomes flood. I then have to flick the servo reverse switch on my TX. Fortunately this is accessible on the front of my TX. However it is annoying when I bench test all ok at home only to find by the time I switch on at the water side forward has suddenly become reverse again! Is there something I am missing?

  • #2
    I think they (Mtronik ESC) are known to do that with some radio gear. Are you using a BEC? Try with a seperate battery for the Tx and disable the BEC on the ESC by removing the red wire.


    • #3
      That's a new one for me. I've never heard of that happening before. I can't even think of how it would happen from the ESC-side. Are you sure it's not an issue with your radio? Does it happen when you turn your radio off then on?

      Perhaps try bench-testing with the sub on and turning the radio on and off. If it flips, I'd say its on your TX side and not the ESC side.

      Conversely, you could try keeping the radio on and turning the sub off then on to see if that flips it.


      • #4
        Thanks guys. Good suggestions. I will give these a try. Bench testing results to follow...


        • #5
          The Mtroniks in one of my RC cars started doing the same thing.


          • #6
            Ok Bench testing complete. I think I now understand what is happening and what the fix is. First of all results - flipping servo reverse switch on TX only works during the current session. By the next time the batt is disconnected and re connected it all seems backward again and the TX servo reverse switch needs switching again.

            What I think I have figured out is this - Remembering that Mtroniks sell two different versions of this speed controller, the manual set up version and the plug and play version. Mine are the plug and play version. So the clever electronics sets itself up from neutral every time you turn it on. It seems to want to shove power down the output leads the same way on its first operation from turn on. If I push the TX stick forward from start up the prop spins reverse. If I push the TX stick backward from start up the prop still spins reverse. So as things are currently wired if I push my TX stick backwards as the first operation after startup the plug and play system locks in to the correct setup, reverse on the TX is reverse on the prop and forwards on the TX is forwards on the prop. This works every single time. So all I have to remember is give the TX throttle stick a quick blip backwards immediately after turn on and everything sets up in the correct way around.

            If I could be bothered, I could swap the wires over on my motor and then I would have to remember to make sure the first operation on TX stick must go forward. But I can't be bothered to un-solder and re-solder the wires on the motor.

            Thanks for you help guys - you helped me find the solution.

            Mankster, I would be interested to know if the quick blip of reverse immediately after turn on solves your RC car problem too.


            • #7
              Hi...i am a new user here. I want to know are you sure it's not an issue with your radio? Does it happen when you turn your radio off then on?Perhaps try bench-testing with the sub on and turning the radio on and off. If it flips, I'd say its on your TX side and not the ESC side.

              china pcb assembly
              Last edited by RickyTerzis; 01-05-2018, 12:07 PM.


              • #8
                Ricky, I am abs positive that it is not the radio TX. I have repeated the experiment and proved it both ways. The plug and play version sets up with +ve going down the same lead every time it is turned on. It detects the first direction you move the TX stick from turn on and locks in as that direction. Just to repeat the above experiments. I turned on and push TX stick forwards, result prop spins reverse. Turn off, turn on and immediately move the TX stick back backwards result, prop still spins reverse. However times I turn off and on again the prop always spins reverse first. Hence my conclusion that power is always fed the same way on startup. Knowing this, I simply move TX stick immediately backwards on startup and the system locks onto this as the reverse, and hence TX stick forwards produces prop spinning for ahead.


                • #9
                  Have you spoken to Mtroniks about this?
                  Time to DIVE IN!


                  • #10
                    No. I am quite happy now that I understand what is going on with the set up. In the end I did just reverse the wires around in the block connector. Now I move off forwards first and all is ok. I don't think it faulty apparatus. I think it is a condition which comes from the way plug and play sets up.