fastfreddie

Long story short, I'm building a "proof of concept" 1/4 hydro and thought I might as well turn it into an RC.
To keep costs down, I'm looking to power it with an EP-1.
Here's a quick look at the boat full size...1/4 scale puts the "proof" model at 24"x12".
http://www.dngoodchild.com/5820.htm (There are much better pics/info on the net but, this was quick/low bandwidth).

The concept is a structural design change...(I plan to mount a 25hp unit to the full scale). The stringers will be raked into the motor board with its included 15 degree angle and the outside frames will also carry this 15 degree rake. This concept gives the motor board the full support of the transom instead of the originally designed "screwed on" motor board that is supported only by the stringers. Additionally, the frames, stringers, cross piece and fore strut will be "beefed" up.

I'm ignorant of the requirements for electric RCs so, can someone tell me how much of my Losi LST radio gear/servos/batteries I can use for this project? I'm thinking most of it, tho' i'll need some way to control the motor. ESC? Can I run the ESC off my JR radio?
What other accessories will I need? (Keep in mind, the RC application is secondary so, think on a budget).
What would be a starting point for hopping up the speed, if necessary?

Thanks, in advance, for your thoughts.

MadManAndrew

Your Losi radio gear should work fine, as well as servos as long as they have enough torque to turn the motor. What model is your JR radio? I'll be able to help your more once I know what size motor it was meant to control. As for accessories, I'm not really sure as I'm new to boating myself. Maybe someobody else can help you with that. With your scrapped-together setup, I'd go for a good set of batteries to get a good increase in performance.

fastfreddie

Radio's a JR XS3 Synth FM. I think it'll control just about anything.
How much torque does a servo need to turn an outboard? Can't be as much as a monster truck. Anyway, LSTs use two steering servos, JR Z590M, each with 85oz/in torque @ 6 volts. Plenty of room in the cockpit for both plus battery packs, JR RS300 receiver and another servo or two, camera, whatever.

My biggest question is understanding how an ESC works, how it's set up, what controls it, etc...I'm pretty sure it's what I'll need to make the motor go.

Thanks for the reply.

MadManAndrew

Electronic speed control (ESC). Basicly, an ESC is a variable resistor bank. Batteries in one side, motor plugged to the other, then plug it into your throttle on the radio, and it changes the amount of energy from the batteries that is let through to the motors based on how much throttle you're giving. From what I can tell, you're radio does not have an ESC. Where do you plan to buy the motor from? I could try and give you a link to a good ESC from the same place.

I'm not really sure on how much torque you would need to turn it, but I would assume that one of those will do.

Chynewalker

Ahhh, an old MiniMax!  Had one of them when I was a kid.  I ran a 7.5hp Merc on mine and it was fast enough.  A 25 will be a handful - and then some.  At 8-feet you will likely run out of boat before you run out of throttle.  Be sure to get a prop that keeps your RPM down.  If you're running a stock prop on your 25 it'll rev well past the redline.  Your modifications will help with the transom strength (that's how "real" hydros are built) but not necessarily with control...  The plans said they would handle that much power, but I'm not sure it worked out that well in reality...