It sounds like there is something wrong with the connections if it runs continuously. A picture might help but I'm not sure how you have connected your motor to the receiver if you are not using a speed controller without seeing it. I suspect that channel 5 might not be a proportional one.  The easiest method of controlling it would be to use a speed controller unit but it will require a spare proportional channel.  Some sort of mechanical switching unit would be possible but challenging to reverse. 

If the motor only has a positive and a negative connection then it is a brushed motor and you need to buy a suitable brushed type speed controller. Mtronics do a specific marine range, called Viper, just pick the one of the appropriate amperage for the motor and connect it into one of the spare proportional channels.

I've just had a quick look through your radio manual and it looks like channel 5 is not proportional.  A fairly typical set up would be throttle on the left hand stick up and down, Channel 1, and rudder on the right hand stick left to right, Channel 4.  You could then use the left hand stick left to right, Channel 2 for the bow thruster control.

Edited By Richard Simpson on 27/01/2022 22:41:17

As a person who runs a pusher tug in steering competitions, with a FlySky i6, I can state that what you want to do is very easy.

You have 2 sticks:-

Left controls left motor (up & down).

Right controls right motor (up & down)

Left controls (via esc) bow thruster (left & right)

Right controls rudder (left & right)

Above is for a 'mode 2' setting, all your manouvers are controlled by the 2 sticks, no need to use any channel other than the 4 controlled by the sticks.

Old saying:- " KEEP IT SIMPLE".

This is easy, I know, because I do it myself with the same radio that you have.

No need for 'Mixing', you can do that with your 2 thumbs on the sticks.

Edited By Kev.W on 31/01/2022 18:01:23

I'm getting ready to do the same thing with a Fire Boat I am rebuilding. Kev.W is correct about a universal setup for the gimbals. However, for a bow thruster you don't need the gimbal control, the SX-I6 has the 3 position switch which should suffice.

One thing you don't mention is where are you getting the power from in the boat. Are you using the power that runs through the servo line or are you using a servo to operate a stitch or switches? You should not tap off of the receivers channel for power.

You might not want an ESC for this function. Just tap off the battery and use a servo to operate either a DPDT (center off) switch or a pair of momentary push button switches, one for each direction the servo arm swings.

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