T-Pain Is On A Boat: Re: [Electric Boats] kill switch

Monday, January 25, 2010

Re: [Electric Boats] kill switch

John,

That sounds like a pretty good way to get a very efficient electric boat. I imagine google will find you some safety switches - they probably go in the control wiring, not the power cables.

A fuse or circuit breaker should be right at the + terminal of the end of the battery string.

Fairing the motor tubes will give a great improvement in efficiency. The round shaft has a Cd of .49, an NACA 0025 foil Cd is .09.

Try an APC 10x6 pusher prop made for an RC model airplane ($3 at a hobby shop). You will have to bore it out to 3/8" and cut a slot for the MK shear pin but the prop is also a good bit more efficient than the weedless model that comes from MK. It won't be as durable as the MK either, but at $3 who cares?

Keep us posted on your results.

Denny

----- Original Message -----

From: john_casperson

To: electricboats@yahoogroups.com

Sent: Sunday, January 24, 2010 6:01 PM

Subject: [Electric Boats] kill switch

Hi all--

Last year I picked up a pair of 16' Prindle cat hulls for free, and a few days ago I found a pair of 45# thrust 12V saltwater Motorguide trolling motors (with continuously variable controllers) which I picked up for $225. This spring, I'll build a deck connecting the hulls to mount the motors, a pair of type 27 Walmart batteries, and a 200 watt solar panel on a T-top for charging the batteries. The controllers will be disconnected from the motors and moved to an amidships helm location, with the batteries stowed underneath.

I plan to test it in the surf this summer, and it occurred to me that even at low thottle, without me on it, it will run much faster and further than I can swim.

Does anyone know of a suitable kill-switch for this setup?
What about fairing for the motor shafts?
Also, how should it be fused?

John Casperson