computerised twin drives help

[Guest]

Laid in bed this morning and had an idea (no not that sort keep it clean)

Anyway have been thinking about my hull Nangee and what to fit as the propulsion,would love to fit schottels ,too expensive.

So have decided on twin drives ,twin controls.

But then what about steering should I fit rudders or just rely on the motors or both.

And what about paired or indipendant.

Then the thought came to me I have a computerised tx why not use the mixing facillitys to control the motors /rudders and have this on a switchable facility so I can then either have the full control on one stick or both for normal .

thanks daz

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[Guest]

I had a u-boat which I sold recently which had the forward and aft planes set up to work together or, at the flick of a switch, they worked independantly.

Using the mixing facility of a radio is a good idea but the downside is that you model is tied to that radio. I would prefer a bit more flexibility and with a change of crystals I have a couple of radios that can operate about four boats.

Another possibility is an on-board mixer which can link your two shafts to the rudder servo and enhance the steering options without the need for additional channels.

I realise though that with a sophisticated radio you would want to make the most of it's possibilities but I would stay open minded for now and have a play with a few differrent options while you can and before you enclose everything. The best bet would be to install the propulsion and have a play with it in the bath (as you said keeping it clean!) and see what you think. You may find the effort isn't worth it at the end of the day.

I have a Deans Marine Cossack that I set up with two independant shafts but it has to be a very calm day before they are any use in manoeuvring. The slightest wind and it goes where it wants until it starts moving when it becomes responsive again.

If the club does a show though and I put it on an indoor pool it always draws comments that it can turn without moving forward.

[Guest]

What about a dual motor controller - something like this

http://www.lynxmotion.com/Product.aspx?productID=89&CategoryID=10

I'm looking for something similiar which would control a 1/35 scale tank using a two channel radio and dual motors.

[Guest]

thanks Alan .Richard i can see your point about checking out with normal controls first before getting too complicated as for the model being tied to the radio ,i dont see how as the mixing would be done by the tx ,not the rx as i would be using a 7/8 ch rx and in normal mode the model would surly opperate as a twin stick ? but more to the point would the model work if it was set up as a mixed type .

cheers daz

[Guest]

That's my point, I don't know if it would. I think you should do some serious experimenting with all your options before you commit to securing all the pieces in the hull and continuing with the model.

That's the trouble nowadays, too much choice!!

[Guest]

i built a RC boat for my son for xmas, its a twin motor hull, i too had the same dilemma, how do i set up the model for him, what would be reliable, what would be good in terms of operating, and ultimately what is the best option for the job.....

so the decision was made - it has no rudders, no nozzles just 2 props !

control is via a esc/mixer in one unit, the board is made by a club member who retails these units...they are ideal for 2 channel boats or tanks

the mixer/ esc/ board independantly controls each motor, so on a standard 2 channel set up if you move the left transmitter stick forward both motors run at full power in the same direction, if you do left stick back then both motors run at full power in reverse, the speed is fully proportional in both directions.....

the steering is controlled in 2 ways

if forward or reverse propulsion is activated and over about approx 40 % of max speed then one motor slows down to facilitate a turn- both motors continue run in the same direction...

if propulsion speed is activated and its low ( less than approx 40% of full power ) then when the steering stick is moved then one motor will actually run in reverse so the model will turn- the two motors will run in opposite directions to facilitate the turn in a speedy manner.

if there is no forward or reverse propulsion applied but the steering stick is moved then the motors will run in opposing directions - one in forward and one in reverse and the model will spin on the spot....

it means very manouverable models, ideal for steering regattas !- the other advantage is this esc/ mixer board also has bec fitted and it means for my sons model boat there is no servos needed !

the board/ mixer/ esc plugs directly into the 2 receiver outputs, and the bec eliminates the need for RX batteries.

the mixer will ocntrol any motor up to 15 amp output and inputs upto 15 volts

and all this for the cost of a standard basic esc !

pm mee if you want more details

[Guest]

I haven't had much luck with the combined Speed Control / mixer board on my tank model.

It's running on a 9.6 volt Transmitter pack and powering some very small motors. Running fine until one of the components on the board went up in smoke and caught fire! It would have looked great in a boat without anyway to put out the resulting fire!

As it was only 6 feet away in the front room though I was able to extinguish the flames prior to it taking hold! Just as well this was only being used in a test chassis though.

:smile11:

Edit: I've taken a look at the board and it's working but I've lost Reverse on the right hand motor - Three of the Fets on the board have melted! I can't read what the numbers where on those either to replace as the others are varnished and very hard to read.

[Guest]

wow - you are having some bad luck, - contact the maker i am sure he will advise on the next step, i am sure he will do the right thing !

sounds very odd that with tiny motors something went into meltdown.....

you cant be overloading the unit with tiny motors....plus it will handle 15 volt input...

and from your message it was working ok to start with....

obviously there was nothing near to short out the board ?

polarity was correct ?

all i can think is there was a malfuctioning component ?

i am not an electronic expert so cant sauggest anything else...

i am sure it will be sorted by the maker, he's a fair man....

[Guest]

I've been in contact with the maker of the board, who said to return the board and offered to replace it free of charge or repair the item.

I think it was a faulty transistor as it was working fine and the motors even when stalled will only pull up to about an amp or so.

The component was really alight though and it took a fair amount of blowing to get the fire out! Luckily I was only testing in a trial chassis, saying that though it would have looked quite spectacular with flames licking out the vents on the engine covers!

[Guest]

I've received the replacement controller board and will soon be installing the item into my test chassis again!

The problem could have been due to a faulty component of lack of supression on the motors I was running.

I'll post details of how the new controller performs later.