Beginners question around battery/motor/speed controller combo

[Aderaat]

HI all,

I am a newbie to RC boat building and am planning to build a device to help me fish in various ways (trolling, long lining, or just simply getting bait out further than I can cast) and in various weather conditions (surf, swell, off the rocks, off the beach etc.)

I am OK with the design side of things but need some help with the electronics.

The basic design concept is a catamaran and simply drive 2 engines independantly instead of having a rudder assembly. I hope to use either a single or pair of heavy duty 12v batteries and as speed isn't the primary objective here but running time is, I would like the best possible combination to maximise operational time, whilst balancing speed/torque/load etc.

What I am after is some sound advice around the best combination for the speed controller/s, motor/s and their respective ratings and wiring before I start the build. Electronics isn't my forte (if you haven't already guessed) so any help would be very much appreciated.

Also any pointers to good resources that help an electronics novice understand the basic electrical elements would be appreciated, especially around calculating load in relation to voltage, current etc. would be very much appreciated.

Thanks in advance for your help!!

Andy in N.Z.

[toesup]

I am a newbie to RC boat building and am planning to build a device to help me fish in various ways (trolling, long lining, or just simply getting bait out further than I can cast) and in various weather conditions (surf, swell, off the rocks, off the beach etc.)

First off, before we can talk motors / electronics, we need to know how big the boat is...

.. and if you are going to run it on the open sea, it had better be BIG..

.. and if you plan on actually catching fish with it, it had better be VERY BIG!

[Aderaat]

Hi there,

I plan each hull to be a meter to a meter and a half long using the batteries as ballast. Built out of high pressure rated PVC downpipe. (nice weather proof screw on covers for access and very versatile and strong).

As a result it will b e very stable and highly bouyant. Will also have a servo controlled line release mechanism in case i get a shark or kingfish.

Make sense?

[mfr02]

For surf, you need it a lot bigger than first thought. Off rocks? A LOT stronger than first thought.
To see at any distance, you need a large visible part above water, not only so's you can see it, but also tell which way it's going.

[toesup]

I plan each hull to be a meter to a meter and a half long

As a result it will b e very stable and highly bouyant. Will also have a servo controlled line release mechanism in case i get a shark or kingfish.

Make sense?

Yes, it makes sense... but its still too small to cope with the sea..

You need to increase your design size by at least 50% if not more..

To drive something of that size you are going to need some pretty serious motors, something with some 'low end grunt' as well as extra speed in case you need to get out of trouble quickly.