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[narrowboater]

Hi all,
I have a problem with the rudder/motor/gun servos on the boat I am building and I wonder if any of you electronic wizards can suggest why it is happening and, hopefully, a solution.


My model has 3 motors and (obviously!) rudders. These are controlled by a Forge Electronics Rudder Mixer Mk2 so that the outer motors help with turning. Although quite big this unit has a range of set-up options which are quite useful. I also have three guns on the model which I have turning using micro servos and a separate channel on my transmitter. These are connected to the receiver by two Y leads.


Now to the problem. With no gun connections to the receiver the motors and rudders work perfectly. If I connect one of the gun servos to the receiver then again everything is ok. If I connect one of the Y leads to the receiver then one of the gun servos to that - again all ok. As soon as I connect a second gun servo to the Y lead and use the transmitter to turn the servos the lights on the mixer unit (which should both stay on until the motors are running) start to flash and the motors start to 'pulse' run and the rudders judder. If I stop turning the gun servos everything settles down immediately.


I have swapped the Y leads and the receiver and there is no difference. To my simple mind the rudder mixer is picking up interference from somewhere, but why only when I connect up more that one gun servo? I have asked Component Shop if there could be a problem with the Y leads (one lead possibly, but two?) but not had a reply yet. I have also contacted Forge Electronics but no reply as yet. I keep coming back to the problem being the rudder mixer and interference but I'm not sure and in any case I don't know how I can prevent it.


Sorry to be so long winded but I thought it best to try and give the full picture. Any thoughts or ideas guys?

[HMS Invisible]

Hi all,
I have a problem with the rudder/motor/gun servos on the boat I am building and I wonder if any of you electronic wizards can suggest why it is happening and, hopefully, a solution.


My model has 3 motors and (obviously!) rudders. These are controlled by a Forge Electronics Rudder Mixer Mk2 so that the outer motors help with turning. Although quite big this unit has a range of set-up options which are quite useful. I also have three guns on the model which I have turning using micro servos and a separate channel on my transmitter. These are connected to the receiver by two Y leads.


Now to the problem. With no gun connections to the receiver the motors and rudders work perfectly. If I connect one of the gun servos to the receiver then again everything is ok. If I connect one of the Y leads to the receiver then one of the gun servos to that - again all ok. As soon as I connect a second gun servo to the Y lead and use the transmitter to turn the servos the lights on the mixer unit (which should both stay on until the motors are running) start to flash and the motors start to 'pulse' run and the rudders judder. If I stop turning the gun servos everything settles down immediately.


I have swapped the Y leads and the receiver and there is no difference. To my simple mind the rudder mixer is picking up interference from somewhere, but why only when I connect up more that one gun servo? I have asked Component Shop if there could be a problem with the Y leads (one lead possibly, but two?) but not had a reply yet. I have also contacted Forge Electronics but no reply as yet. I keep coming back to the problem being the rudder mixer and interference but I'm not sure and in any case I don't know how I can prevent it.


Sorry to be so long winded but I thought it best to try and give the full picture. Any thoughts or ideas guys?

You shouldn't apologise because you gave a perfect description of overloading the receiver power supply.

I'm guessing this supply is some kind of over- current & thermally protected regulator.
Is that so?

[StudioJohn]

Hi there this is John from ScaleWarship (Forge Electronics). I haven't received any communication from you regarding your problem
Can you please contact me. Tel and email on Scale Warship Website

[narrowboater]

Hi John,
I originally sent you an email but missed the W out so it was returned as undeliverable. I then sent it again this time with the W and got a reply from Google which I have never seen before saying they were having trouble delivering the email but would keep trying for 22 hours. Since then Google says they couldn't deliver it. Very strange!


However, I will give you a ring tomorrow,  any time best for you?

[narrowboater]

Hi Microgyros,
Not sure what you mean by overloading the receiver power supply. The receiver is powered from one of the Mtroniks 25A ESCs. Would fitting a UBEC solve the problem?

[StudioJohn]

Sorry for the email issues. Please call anytime

[T888]

Hi narrowboat,


I’d contact John at Scalewarships as he’s very helpful. Contact details on the web site.

[HMS Invisible]

Hi Microgyros,
Not sure what you mean by overloading the receiver power supply. The receiver is powered from one of the Mtroniks 25A ESCs. Would fitting a UBEC solve the problem?

It is one of several solutions but not the easiest. But you haven't revealed information on the input battery or receiver.
A fault finding tennis match is quicker over the phone is best so perhaps you should give John a bell, even although it is a servo & supply issue.

[cos918]

Hi Microgyros,
Not sure what you mean by overloading the receiver power supply. The receiver is powered from one of the Mtroniks 25A ESCs. Would fitting a UBEC solve the problem?

You are using the BEC in the Mtronics esc. as you add more load ie the second servo it can momentarily shut down or go low on out put voltage. This can cause other units to do weird things.
I had something like this happen on my ferry. I disabled all the mtronics becs  and used an external 5ah bec. Had no problems since .


John

[HMS Invisible]

You are using the BEC in the Mtronics esc. as you add more load ie the second servo it can momentarily shut down or go low on out put voltage. This can cause other units to do weird things.
I had something like this happen on my ferry. I disabled all the mtronics becs  and used an external 5ah bec. Had no problems since .


John

This is what I believe is happening but it is also why I asked about voltage. 

Narrowboater might have too low an input & also get away with a 220uF capacitor to buffer the receiver voltage. After looking at a voltage trace on a scope it would be the first thing I would try as a diagnostic.

The ferry had 12 volt supply, high drain 550s and a single rudder servo.
The distinct on/off timing of cutouts on the ferry pointed to thermal overload which was cured by disabling the bec in one way.

[narrowboater]

Thankyou Microgyros.
You saying about receiver voltage kicked a couple of the little grey cells into operation! I had a similar problem with my big landing craft where the winch servo which controls the front ramp wouldn't lift it without everything cutting out. Fitting a UBEC solved it.
I've now fitted a UBEC into this model and everything seems to be working correctly.

[narrowboater]

Hi cos918,
You probably have now read my reply to Microgyros. Fitting a UBEC as you did seems to have sorted everything out. You say you disabled the BEC in the Mtroniks ESCs, did you just disconnect the red wires or what?

[narrowboater]

Hi  again all.
To put matters right for anyone reading this thread, I titled it with Forge Electronics Rudder Mixer as I originally thought that was where the problem lay. I  now know that the rudder mixer was NOT, repeat NOT, at fault at all and is working perfectly. If you have the room I would recommend that you give one of these units a try. It is fairly easy to set up and has lots of options as to how you want to set it up to suit you. And no, I am not getting anything for saying this! I just don't want anyone thinking the units are iffy because of what I originally said.


Thanks for your help with this,
Take care, don't be an idiot, stay safe.