Esc for twin motors

[Chris ScherrerParticipant @chrisscherrer92246]

[Chris ScherrerParticipant @chrisscherrer92246]

I have built the Riva Aquarama from scratch and installed a couple of brushed motors. To run them I found a esc for twin motors on line. They work fine but now I am thinking of changing the motors to brushless to increase performance. Ideally I like to run them the same way with a single esc. That way both motors are governed by a single channel on the rc and the boat is easier to steer.

The issue I am having is that I cannot find a twin motor esc for brushless motors.

Has anyone come across this and is there a way around it?

[Charles OatesParticipant @charlesoates31738]

I'm afraid you won't find one, brushless motors exchange information with the esc so 2 motors would give conflicting signals. There are exceptions to this, but not worth considering.

The answer to your problem is simple, use 2 esc s connected to the receiver with a Y lead so they both plug into the same socket on the receiver. As long as the motors and esc s are the same you'll be ok.

Another option is if you have a computerised transmitter that will let you have 2 receiver sockets respond to one stick movement, that sometimes allows other options like mixing. Personally I like to keep things simple and just use a Y lead.

Chas.

[Malcolm FraryParticipant @malcolmfrary95515]

Running 2 brushless motors off one ESC has been done successfully, but with great care. Identical motors, identical wiring, identical loading, great care taken to ensure that the ESC chosen could handle the power of two motors. The idea can only work with unsensored motors, as sensors would only create confusion.

Much simpler to use one ESC per motor on a Y lead. Has the advantage that you get to put the (smaller) ESCs where you want them, rather than planting one larger one where it decides.

[Chris ScherrerParticipant @chrisscherrer92246]

Thanks guys. Your response is much appreciated. I was trying to save a few bucks and some space in the hull in not having a second esc. Malcom's idea of using only one seems too complex as I would have to split the 3 wires of the esc to service both motors or connect them in serie. (should that be feasible) And then there is the battery feed to consider. And what size esc would I need. These are all questions for an electronic wise person which I am not really. Although interesting it would be and a challenge. The risk of damage to components is definitely there.

I will invest in a second esc and a futaba Y harness.

[Empire ParkstoneParticipant @empireparkstone]

Could be cheaper fit one prop (if practical) one brushless one escape I changed to one brushless one prop to replace 3 and 3 MFA 850's

[Chris ScherrerParticipant @chrisscherrer92246]

One prop only would be cheaper but it would not reflect the real Riva.

[ashley needhamParticipant @ashleyneedham69188]

What brushed motors do you have fitted? And do you know what current they take?

A wattmeter is a handy device as it shows not only the power being consumed/developed, but can be used as gauge for how much the motors are being loaded.

28mm outrunners are an adequate replacement for anything up to a speed 600, and they come in various Kv and wattages, so this would have a bearing on what esc you need.

Ashley

[Empire ParkstoneParticipant @empireparkstone]

Only those who were viewing underwater

[Chris ScherrerParticipant @chrisscherrer92246]

Ashley, no sure what brushed motors they are. They measure 36×56mm. It's been a while since I'v installed them. The replacement would be something like 2840. I did read somewhere that for boats it is better to have an inrunner motor installed. Something to do with cooling.

[ashley needhamParticipant @ashleyneedham69188]

While inrunners can be cooled properly with a water jacket, that should only be required if you are talking high power, highly loaded items.

If you choose the right outrunners and check that they are not being overloaded then you should not need cooling. A motor that’s running happily will get warm or even hot, but not to the point it needs cooling.

Sounds like some sort of 540. A standard 540 struggles to develop 40-50 watts or so, and the cheap 28mm brushless motors all seen to develop at least 80 watts, so some 1400Kv ones should do, on a 6-cell Nimh stick.

Ashley

[Charles OatesParticipant @charlesoates31738]

Hi Chris, like Ashley says, the old motors are probably some type of 540 ones. Over the last couple of years I've replaced 4 of these in my models with brushless motors. My lightweight crash tender/ fire float has a 28mm outrunner, as has my rtll. Both are faster and run longer with no heating, water cooling would be silly in models like these that are running well within the motors limits. I've also a large heavy Garr Wood Speedster, with a 35 mm outrunner that runs fast and cool.

The point is that I would recommend outrunners for normal models, no cooling needed. I just chose a kv rating to match the battery voltage in each model, it's that simple.

Charles.

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