T-Pain Is On A Boat: Re: [Electric Boats] new member, bruce

Friday, July 25, 2014

Re: [Electric Boats] new member, bruce

Good point on the rust, the marine environment can be brutal. As to overheating the setup is not designed for continuous load. Probably a 50% duty cycle at most. I have seen some electric boat setups that incorporate some copper tubing wound around the motor and presumably raw water is pumped through. I might do that.

Thanks for your input.

On Jul 25, 2014, at 1:10 AM, "CNC 6-Axis Designs gcode.fi@gmail.com [electricboats]" <electricboats@yahoogroups.com> wrote:

the motor will likely overheat under sustained load.
it will maybe also rust within the year.
just a caution.

On Jul 25, 2014 5:44 AM, "Mark F mark.internet@yahoo.ca [electricboats]" <electricboats@yahoogroups.com> wrote:

I have tried running a 3hp treadmill motor using an inverter.

The controller used SCR's and the motor was rated at 90 volts DC.

In my experiments, I found you would need an expensive inverter to drive the power required.

I also had losses from the inverter.

If you have a bank of 10 12v, I would suggest a DC motor at around 100 volts and a controller to match it.

Unfortunately I haven't found a reasonable priced controller at that voltage with relatively low amps.

I have used a 48 volt controller, which was reliable, but was low on top end speed.

good luck

From: "Bruce Wilder brucewild@gmail.com [electricboats]" <electricboats@yahoogroups.com>
To: electricboats@yahoogroups.com
Sent: Monday, July 7, 2014 9:53:03 PM
Subject: [Electric Boats] new member, bruce [1 Attachment]

[Attachment(s) from Bruce Wilder brucewild@gmail.com [electricboats] included below]
Hi, I'm building a 25 foot flat bottom houseboat. During my first float test at #3500
It drew 5 1/2 inches. At full weight of 7000 or so it should not draw more than a foot.
I'm aiming for extreme shallow draft gunk holing, no blue water for this barge.
My primary power will be an old Volvo 130 HP Stern drive taken from a ski boat.
I know, I'll probably have to re-prop from the stock 15-17... But that's for another forum, right?

I haven't looked through all the archives yet, but I doubt what I'm planning has been tried.
It may or may not work but that's the fun of trying new things.
I have a 3HP 220 V single phase motor off an old DeWalt radial arm saw. plate shows 3500 rpm
but i dont know if thats load or no load.
The power might come from a battery bank of 10 12v running thru an inverter or direct from my 8500 watt gen set. which has a 220 30 amp output.

Now, the kicker, no pun intended. the output will be through a Yamaha wave venture jet pump.
this pump is factory rated for 6500 rpm on a 50 HP motor. of course I dont expect much speed, probably just a few knots, but that is ideal for my need for extreme shallow draft or emergency get home power if needed. I'm picking up the motor from Salinas (CA) Armature tomorrow where they have mounted a 35 tooth cog wheel. I'll have a 21 tooth wheel on the pump so that will give me a slight boost in RPM on the pump. (supposedly)