Vintage dual prop rc boat conversion

[stavie131]

I have a vintage SunRunner SN-61 that was my fathers and I would like to convert it to modern electronics.

This is my first time doing custom work on an RC boat, I do however have experience building rc crawlers and bashers.

I would like to keep the dual prop setup with NO rudder. I want this to be a "sleeper" build.

Help with what electronics to choose would be helpful, I will be using a spectrum DX5 rugged radio.

The original motor diameter is 24mm and the original prop shaft diameter is 2.48mm.

So I need two motors, two escs, couplers and advice on how to setup the two escs together so I can steer and throttle.

Thank you in advance!

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[fweasel]

Steering a twin boat without a rudder using a pistol style transmitter will be challenging. You'd need a transmitter high-end enough with channel mixing that could be manipulated with another channel. Outside of my wheel house, and not even sure of it's possible. Significantly easier, and more reliable, would be a two stick 4ch transmitter. The two ESC's would be controlled on their own channel, mapped to the vertical stick action. You'd steer with tank style stick maneuvers. That's the approach I'd take if I was set on operating that boat in that manner.

As for electronics, I assume you're going to go brushless and lipo. Those are fully submerged toy grade, plastic props. You won't be breaking speed record, or pulling amps, so small brushless marine ESC's will be all you need. I would imagine 60-80A ought to do it. A pair of small Leopard 2845 motors (still probably overkill) in the 2500-3000kV range running on 2S would keep things under 20K RPM. I have ZERO experience running a toy boat with dual submerged plastic props and have NO idea what the original setup RPM was, so these are just guesses. If you guess wrong on motor kV, you can always adjust it by increasing/decreasing battery voltage.

[stavie131]

I've decided to get a rudder for simplicity since I don't want to buy another radio.

Can I run two brushless motors off the same esc?

[Peter A]

Can I run two brushless motors off the same esc?

No! You could however run two small brushed motors off one esc like a HW 1060, or a Tamiya twin esc.
I would suggest if you go brushless use a couple of small outrunners and 30A esc's.

[fweasel]

To run two brusless motors, you'll need two brushless ESC's. The ESC receiver wires get combined with a Y harness and connected to the throttle channel of your receiver. If the ESC's have a BEC feature, you'll need to cut or de-pin the red wire on one leg of the Y harness so only one ESC powers your receiver.

[stavie131]

Ahhh the Y harness makes it simple, no channel mixing that way!

Now with a dual prop setup, can I run a single rudder?

[fweasel]

yes