Here is a link to Malcolm Moss's website if it may help.
Cheers, Alex.
Sent from my iPhone
Begin forwarded message:
From: <foster73@outlook.com>
Date: 10 January 2017 at 04:20:56 GMT
To:<electricboats@yahoogroups.com>
Subject: Re: [Electric Boats] Electric paddlewheelMalcolm Moss is a good man to talk to about electric paddle wheels.
He is the President of the Electric Boat Association in the UK.
Paddle wheel boats are his favourite and he has quite a lot of knowledge about them.
You may be able to google his email address and contact him, otherwise I shall ask him to allow me to give his email address if you request it.
I hope that may help.
Alex.
Sent from my iPhone
On 19 Jan 2017, at 09:36, alexander jones 73foster@live.com [electricboats] <electricboats@yahoogroups.com> wrote:
Malcolm Moss would be great person to discuss this with.
He specialises in Paddlewheel projects and is President of the Electric Boat Association in the U.K.
He has some good Paddlewheel projects with the Moss Solar Company.
If you get in touch with Malcolm he will have a chat about certain aspects.
Sent from my iPhone
On 19 Jan 2017, at 08:42, Hannu Venermo gcode.fi@gmail.com [electricboats] <electricboats@yahoogroups.com> wrote:
I am 99% sure that paddlewheels are no-where near 90% efficient at any
speed.
Think of it this way.
Pull the craft with a rope, using motor output as the measure of power used.
This will have zero slip and the power transmission will be 100%
efficient (no stretch on rope).
OR like this.
A human being can output about 100W max power, for a short time, when
trained, like on a bicycle by an athelete.
Pulling by hand, when standing on shore, the power is perhaps 20-50 watts.
By hand, you can pull a heavy 28 metric ton, 24 m powerboat (Baia
azzurra, 2x1300 hp, 60 knot deep v hull) at about 1 km/hr with no wind.
The boat will move exactly no-where with a prop or paddlewheel when
powered by 50 Watts.
You can also pull a 70 metric ton steel riverboat / lakeside craft by
hand, a bit slower, but it moves just fine.
What do You need in terms of hp ?
No idea whatsoever.
But since electric motors are cheap, or very cheap, does it matter ?
I would use an inverter and a 3-phase motor or better yet a servo motor,
both at 220V (50 hz, EU).
Since they are;
1. more efficient
2. cheap
3. any power levels are available for little relative cost 0.5 hp - 1000
hp or more
4. are meant for continuous duty and will last forever
I think most other motors would not last at all long, if actual use will
often or usually be 5 hours per day.
My thinking is influenced by the fact I went from 48V DC to 72 V DC, and
from 3-phase motor with VFD to 220V ac servo brushless, and the
difference is enormous.
Using several makes of drivers.
A 1-2 hp 3-phase motor is about 100$, and any power level is not much more.
Second hand is likely fine, and you can probably get 1-10 hp for not
much more.
Surplus center shows a 2HP one for 150$, and 5 HP for 406 $ new.
http://www.surpluscenter.com/Electric-Motors/3-Phase-Motors/3-Phase-Motors-Base-Mount/?page_no=1&fq=ATR_Motors_HP:5
Ebays shows new 4 kW VFDs for 150$, chinese (they will usually be fine).
Or a used hitachi 4 kW for 120$.
For my druthers, 4 kW motor + Hitachi VFD.
5 kW (20 kW peak) 12V - 220V inverters show up from 380 - 460$, ebay,
chinese.
And a heavy gearset to drive the paddlewheel.
Make sure the power electronics do not collect humidity, so they dont
rust inside !
A preventive laquer coat from the electronics shop might also be in
order, after they have been run a few times for a few hours.
HTH.
On 18/01/2017 20:03, elwelldon@yahoo.com [electricboats] wrote:
> But what DO i need in terms of HP/torque, etc. In a paddlewheel,
> torque, not speed is the issue. I suppose I could take a 1000W
> electric and chain gear the thing down from 1500 to 40 rpm at the
> wheel (which would probably exhaust the motor shortly), but you see
> the variables. Paddlewheels are about 90% efficient in transferring
> energy to the water, but only at low speeds, but that's fine. Not
> anticipating the boat operating for more than about five running hours
> a day.
>
> We are currently planning on something like four 100AH batteries wired
> up at 48 volts.
>
> More thoughts kids?
--
-hanermo (cnc designs)
Posted by: alexander jones <73foster@live.com>
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