Lew

Thanks for the feedback, the battery part of the wiring diagram should be only be taken as a guide. The battery comfiguration can vary. I have up to three batteries in parrallel as I would prefer to use batteries instead of lead for ballast. Certainly on many of my boats I only use a single battery to run twin screws. I should have indicated the battery side of the diagram is only a guide when posting.

About the dual motor setup...

I see you have two batteries in parallel (only one is needed if the amperage is sufficient). A better setup might be one battery for each motor ESC. There could be a relay on the BEC circuit to run the receiver off one battery then switch over to the other battery giving the receiver power to the "last surviving battery".

Just a thought.

Lew,
Florida ⛱️, USA

The attached wiring diagrams are used within our Association for single and twin screw boats. Hopefully they will be helpful if used with Lew's diagram

Finally got around to finishing the document for my recommendations for a Basic Model Boat configuration for those not familiar to this. I have it in the "How-To-articles" on this site. Hopefully this will help new model boaters understand the basics to start the process to their project.

Also, thanks to all for the nice responses! Hope to be around and continue in this fascinating hobby and the sharing of ideas on this site.

Lew
Florida 😎, USA

Duck

Sorry, the readings were taken in a test tank. The boat is pushing against one end of the tank with both motors running full speed. The 2.5 A is total current from the battery. The actual reading when the boat is on the pond will be less than this as the boat will be moving. In the test tank it is trying to accelerate and so will be drawing additional power. By way of information the readings wre taken on a 72 scale WW2 Captain Class frigate. We have had much the same readings on a 72 scale Modified Black Swan class.

Hope this helps
Cheers
Bob

Bob.

Thank you for the information. The 31ZY could well be a useful motor for me.
One clarification please. When you say twin 35mm props and 2.5A is that one motor for each prop and is the 2.5A the total for 2 motors or the draw for each motor (ie 1.25A per motor when driving one 35mm prop)?

Duck

We tend to use a 4mm shaft with a threaded end to take a prop with the small motor (31ZY) I have seen props from 20 to 50 mm used. These work fine. We usually get them from the one boat parts supplier in Australia (Float a Boat) and the brand are Robash (excuse the spelling if req'd) In all situations I have not seen any issues. I should explain that we are a scale model association and so speed is not all that critial. Also we have some members who carefully bend/twist the prop blades and can adjust the speed.

We have tested the motors under load in a boat fitted with twin 35mm props and the currents draw was around 2.5A. We run for an hour on sailing days and a 5 AH Lithium Iron Battery is, I estimate from recharging, about two thirds spent over this time.

Hope this is of some help.

Cheers
Bob

Les,

80cm length seems to be about the average length for scale model boats. With a mild performance type boat you should have no problem (unless you are in a remote area) in finding items without breaking the bank.

It probably would be helpful if there was an easily findable section on Model-Boats that new members could access such recommendations. This is probably the most common question and undeniably there will be many, many opinions.

Also, the Hobbywing 1060 brushed is a top performer for the price (I have at least 10). Don't worry about the fancy motors. An inexpensive 3xx series will work fine.

Lew
Florida, USA

Bob (in Aus?) thanks for the detail on the motors etc, I have been able to find UK suppliers for what your describe (took only 15 mins). I like the equipment you describe and the UK cost is very reasonable. So...thats what I am going to try and thank you for that! There is a question from another forum member on Props, would you have any advice on that for sizing etc?
Appreciated.
Les

Bob

It would be very useful if you could tell us what props are used with these motors and thrust/ amps. The more data the better. TIA.

In our model boat Association we use 31ZY permanent magnet DC motors 12v 3500 RPM (or you may run it with 6V) which we have found to be very reliable for smaller boats. About 50 of these motors have been motors successfully fitted into members boats with no issues. For larger boats we use an XD-3420 12V (3500 RPM version) again about 35 of these are running in boats within our Association without a problem. For Speed controllers we use the Hobbywing 1060 and we have over 100 of these EScs running with no issue. Albeit we did have one fail when a new member wired it up incorrectly. All items are available through Aliexpress, although other suppliers may have them as well. Hope this is of some help. The items I have indicated are supplied by our Association for members to buy and we have been doing this for over four years now.

Cheers
Bob