Yes I believe my Transmitter/receiver are programmable , I have two Turnigy GT5’s. I currently have not tried or know what/ how to do it I will at some point have to correct this . The projects I currently have or plan to do are the S91 , I would like to build 2 S-38’s , another S-100 and have in storage PT596, and Trumpeters 1/200th scale Bismarck and Rodney , …I foolishly gave my wish list to my local hobby shop and I may regret it ….lol the shot list is the rest of Trumpeters 1/200th scales and a flower class corvette …My life and finances be long enough for both I hope …lol
Bill G.

HI BG
Since posting my previous reply I remembered that some years ago I used a similar system in my Aerokits Solent lifeboat. I was using a Bob's board to control both motors and two channel radio. My problem was that the long protruding keel on the model was overcoming the rudders, so the model would turn about 45deg then swiftly revert to going straight ahead. I managed to use two microswitches controlled by the rudder servo to switch off the inner prop motor when turning and it worked.
This was only disconnecting the motor and I used to slow down when turning so no high currents flowing. Pics attached to show my set up and the model.
I still do not recommend switching from forwards to reverse but stopping the inner motor in a turn is certainly a possibility.
dave976

Hi BG
Relays and switches have many uses and will reverse the polarity to your motors. However this should only be used when the power is being applied for the first time and never when the motor is revolving with or without power. A revolving motor will have a considerable amount of energy in the drive train and sudden stopping and reversing will place a great strain on the electrical components not to mention the mechanical strain on the connectors and prop. You risk damaging the ESC and losing your prop and possibly damaging the motor. Whilst brushed motors can have their rotation reversed by changing the polarity, brushless motors are connected by three leads and direction can be reversed by swopping any two of the three. This is done with the power off so not possible as you suggest.
You have not said which 6 ch Tx you are using but many modern sets allow for some programming which is perfectly feasible and is used by many modellers.
Please ask for more details if your Tx is programable?
dave976

I am new to RC and have given this topic thought , as I have difficulty operating a stick radio , a little bit of knowledge can be dangerous and having a background in electrical and electronic assembly my thoughts run to a relay that would switch the polarity to the motor . Either brushed or brushless …I have looked at available relays and have yet to find anything to my liking but have a couple of double pole double throw switches that are rated for my current motors amperage. I was thinking of using a system where the switches would be mounted to activate off the rudder and that any turns would automatically switch the inside / turn direction motors polarity but not be effect the speed control. Is this something I could follow up on or is there a reason that electric speed controls or motor loads make this an unwise option?

I use a 6 channel land transmitter that you often see for RC cars and trucks …
BG.

Hi Lew,
My 52in CB90 Command Boat is a high speed boat but can also be very manoeuvrable in tank mode.

I use a Flysky i6 mixer modes to switch between tank mode and single stick mode.

It can turn in its own length spinning on it own axis.



Uses two props and two rudders.

Regards Roy

Hi Lew
Like you I have used both joysticks for "tank control" of two motors. As an ex RC flyer I had no problem with using multiple sticks. I use mode 2 so the left vertical stick is the standard motor control and mine are all free moving (no spring), I adjust the centre manually. The right vertical stick is used for the second motor, and the right horizontal stick for the rudder. I control by advancing the left stick just a little and then move the right sticks to increase speed and correct direction. I then adjust both vertical sticks to cruise speed and thereafter can easily control the model with just the right sticks. On my RMS Olympic I use the right horizontal stick, but only when approaching max speed. For a fast boat I would use the mixing facilities to advantage. On a fast PT type boat it is wise, as you say, to reduce speed on the inner prop when turning and mixing the rudder with the two props makes control a doddle. I like the idea of using a switch as forward is the only direction used, and my brain struggles with remembering which direction to push the stick! I have used the Taranis Tx but FlySky is easier to use and if you really want the latest the Radiomaster is replacing the Taranis as it has multiple protocol output built in.
dave976

I have built several models with two or three motors. For me i got used to using both joysticks for the tank control. At low speeds and maneuvering the "tank control" is great. For example, a wide high speed turn, say left, ease off on the left stick and keep the right stick up. If need be, use a little left rudder.

(As I also have several tanks, the radios in them use one stick for F/R & L/R. This is a combination of the up/down and left/right movement of one joystick, not to be confused with the rudder control.)

My towboat has all of the rudders (six, two "barn doors" and four flanking) and they are all linked together and the boat turns 360 in less than its own length while on its own. Her is a seven year old video of the boat doing just that:

I never looked into thee "mixing" features some of the more advanced radios use. Any thoughts about that?

There are also arguments on the control of three motors especially on fast boats. Some say use only two motors. My PT boat (1/20 scale at 47-1/4") runs on three motors for high speed. The outer two have the "tank control" using two joysticks, each on an ESC. The center motor is turned on/off with an auxiliary switch that is for forward only. I just flip the switch after the boat tops out on the two outer motors. There is a noticeable improvement in speed.

Works for me.

Lew

Hi Stan,

I too had what they call 'tank control' on my RC boat, Remember to ensure both controls have auto neutral(centre)on the sticks.
I added a switch to join the two channels together, the reason is that 'tank control' is quite difficult to master especially at higher speeds.
and it is nice to be able to switch to a single stick control if needed.
I cracked open my Transmitter case and added a dual switch, please note you do this at your own risk, this switch is drawn from memory.

Regards Roy

Hi BobbyN,
Many thanks for your reply to my query. I am not in a position to need a dual throttle control at the moment but I will certainly bear your system in mind for the future. I have never seen anything like it in the UK.
Derek.

I was definitely admiring that setup as well. Maybe for my next build I will look into it. For my tow boat build having the independent right and left throttle with the independent right and left rudder I believe will allow it to work as the real thing. I do like the looks of the dual throttle though.

I do want to thank all those who have posted here I greatly appreciate your input.

Derek

The throttles are 3d printed. The set I posted a photo of is about 6 years old and still going strong, albeit the paint on the handles could do with a touch up.

I have found the system to be excellent. A number of people in our Association prefer to us the left and right gimbals because they have had considerable experience using them to control port and starboard motors, but a number of our members now use the dual throttle and swear by it. They are just a replacement gimbal, so 4 screws and then plug in is all that is needed.

If you want one my grand daughter used to sell them on Ebay, she is just finishing her HSC so has been fully committed and I uderstand has taken down the add. Unsure if she has any left but if you like I will chase for you, just give me your email.

Hi BobbN,
That looks an interesting set-up with the twin throttle sticks. I presume that this is an aftermarket fitting and not FlySky. Can you give some details please?
Derek.

Hi, have a look how rc caterpillars or tanks are configured. They have the same dual drive.

Thanks for the diagram, I thought that would be the way to go but wasnt 100% sure. Also I intended on adding a throttle gimble to the other stick, channel 3 and 4 as you mentioned. With the tow boat being able to adjust throttle independently and rudder independently gives it the ability to turn on a dime even with a large tow. 👍

Big Rich is an amazing resource, give him a call...he is MACK Products, and all his stuff is skookum!

bigrichmodels@optonline.net

Hi

Here is a simple wiring diagram for twin throttles that I use. Also I use an upgraded twin throttle gimbal for control hence it runs on channel 3 and 4.

Withonly two exceptions, all of my other boats run multiple motors independently. I simply put a throttle on each vertical stick of my radios. I do have the advantage of being able to mix the throttles so that, except for docking or emergency manuvers, I can run both motors off one stick. Frees up my other important hand... the drinking one.😁
As previously mentioned, do make sure that you disconnect one of the red power leads of one of the ESC's( only if they are BEC equipped).

Is your tx programmable?

CB90 Has the right way to go.

Hi ,
Main thing to remember is, if they have built in BECs (Battery Elimination circuit) you should only connect one of the positives from the ESCs the other should be disconnect.
I personally take the connector (Red) out of the 3 pin plug and wrap it in tape to isolate it, it can then be reinserted if you need to.
I hope you understand, I am sure someone has a diagram that will explain better.

Regards Roy