I decided to add a safety cutoff loop to this boat. The loop is wired to the batteries so that the motor will not work without the loop in place. It adds several inches of wire but I believe it is worth it as the propeller on this boat extends past the transom quite a bit.
I used 6mm connectors for the loop. The female connectors are glue to a thick piece of plastic that is then screwed to the hull. It is removable so soldering in a different speed control is no big deal.
I decided to change the 700 class brushed motor for a Pro-Boat brushless motor. The boat was plenty fast with the 700 motor but the hull will easily handle more speed. Also, I wanted to go with lipo's and this speed controller has a built in cutoff especially for them. The speed controller includes a bec so I don't have to worry about dear receiver batteries which was a problem during sea trial 3.
The lipo batteries I'm using in this boat are 73.4 volt 6 amp units. They should provide plenty of power and run time.
The lip batteries are 2s1p meaning they are two batteries wired in serial. To charge them correctly, a balance unit is used to make sure that both batteries in the pack are charged equally.
Sea trial #3 demonstrated the fact that I needed a turn fin. The one I had on hand is a Fine Design medium right side. I really would have like to have added a left side one as well but I didn't have one on hand.
The turn fin was mount perpendicular to the V of the hull. It's held on my two wood screws that are attached to a plywood doubler glued inside the transom of the boat.
Hopefully this will improve the turning ability of the hull at speed. I'll find out when I get around to doing Sea trial #4.
