I haven't abandoned you

I'm working on a design for the VAWTs.

FGA's to FAQ's

I know this post is redundant but I'm hoping for some fresh hits from the wind power guys and I figure I'll do better if I move the buffet closer to the front door.

The craft is designed to be very light so that it will be easily propelled thru the water. I was a little too successful in my design in that the boat itself, stripped, will weigh less then 800 lb. (360kg).
It will need to weigh 2200 lb. (1000kg) loaded to draw enough water to keep the props at an effective depth.
This is a plus in that I could easily jump from a total of eight batteries to twelve and still have plenty of left over GVW for gear and supplies.
The negative side of the weight issue is that with around 170 square feet of deck and canopy, she could be flipped pretty easy by a strong gust of wind at just the wrong angle.

The Solar panels will articulate. The plan is to hinge them along the ridge of the canopy with some low-tech manual props at the sides of the canopy. There are two issues here:
The river physically runs east and west more often then it runs north/south.
Tilting the panels will give me an even bigger profile in the wind.

The system must to be split into two separate, isolated units.
If anything happens to fail while underway, I need to get the heck out of the shipping channel. There's no breaks on a commercial barge and they would roll over my little boat like a bus over a cheeseburger.
No way I'm putting my eggs or may ass in one basket.

I'm using inboard electric motors with fixed propeller shafts for several reasons:
Conventional electric trolling motors are not designed for full time primary drive or long term immersion.
I can buy two industrial grade DC motors, ESC's, a couple of batteries and a months supply of Guinness Extra Stout for what it would cost to buy just one "Torqueedo".
I can experiment with efficiency of the drive fairly cheaply.
Varying gear ratios between the motor and propeller shaft would only cost me a pulley and a belt, I can use Piranha Props which have interchangeable blades. This allows me to try different blade pitches without the cost of replacing 2 complete props.

Item last would be the wind turbines. I'll need to go with VAWT's.
The 'squirrel cage' will have a maximum diameter of 24" but they could be as tall as 6' with supports at the top.
With the VAWT's mounted in the 4 corners of the craft, they run serious risk of damage in the locks and at dock side.
They'll need to be removable.
I'm considering hard mounting the housing containing the stator and rotors to the craft and being able to lift the masts and fans out of the alternators when the need arises.

I've started to research the turbines.

There's a LOT of information to wade thru.
The manufacture is something I can easily do,
...the design is another story.

The research and a couple of projects that came up late in the week kept me from posting the new drawings, they'll be up tonight.

Seems like I only open my mouth...

...to change feet.

The Skipper of the Greenhorn I (who's also an EE) got me straightened out as far as what happens to the output of 12V wet cells when the power gets low.
Short version: my stooges switchboard is toast.
It's all good, all I'm out is the one sketch, I'm saving myself some hardware and the support crew is sleeping much better.
The "How to get electrocuted" in the last tag line didn't sit well.

I had planned on getting some of the newer prints up on the blog this weekend but there's apparently some kind of a software issues between my iMac at home and my iBook at Casa Support Crew.
Hopefully I'll make it up to you later this week.

Drawing is a chore.

I'm still turning the sketches into 1:12 drawings I can have printed.
I'm also starting to work on details like battery placement and
conduits for the wiring harness.

I had another idea that I want to bounce off the engineers.

I expect it's going to be difficult to keep the batteries charged
and if the onboard system can't keep up with the consumption on
any given day, adding more batteries really isn't going to help.
I'm thinking maybe if I were to add more batteries for ballast,
it might be helpful if I could reconfigure them.
When battery power got low, rather then run the risk of cooking off
a motor running it on voltage that's too low, I could switch from
(for instance) 6 pairs of 2 batteries to 3 pairs of 3.

The setup I had in mind is pretty simple. Picture an old fashioned
telephone switchboard from a 3 stooges flick.
I get a bunch of high amp connectors of the type they use on welding
cables, I run the leads to the ESC/motors down either side of the
battery bay with a series of female connectors in the lines.
Each battery terminal will have both a female connector and a pigtail
with a male connector that can be plugged either into the feeder
cables to the ESC/motor or into the battery next to it.

Piranha Prop's and a "virtual Elvis".

The sketches for the hull and deck are essentially done.
I'm transferring images to a set of prints I can actually build from.
The belt drive is now enclosed inside the pontoon and the tail comes up from the keel at a shallower angle with a smaller transom.

I was figuring on a relatively low prop RPM with an aggressive pitch. Amazingly, this is what one of the engineers at Piranha recommended when I contacted them.

Piranha has an interesting concept.
They make hubs to fit different outboard and I/O drives and you can buy blades in sets, separately and/or individually.
If I were to whack a blade(s) or decide I want to experiment with a different pitch.
I can purchase new blades rather then a whole new prop.

Tech support there are really accommodating!
When she didn't have an answer she forwarded my inquiry to one of the engineers ...unfortunately the fact that the engineer didn't read more then the first sentence in the eMail was painfully obvious from his response. But I cant fault him, I'm sure the questions fell out side of his job description and he had real clients to deal with.

I'm definitely going with the piranha prop. When I shoot the documentary, the girls in tech support definitely get a plug...

My support team liked "scale man" so much they want to see a "virtual Elvis" as well so...

He'll be onboard the next set of sketches.

More drawing, more problems

I started to do more math and it looks like the GVW of this boat isn't going to be even close to the 2200 pounds she displaces.
Which means the props are going to be splashing like bass on the surface and if I were to get a good gust of wind up under the deck and the canopy, she's going to turn turtle on me.
I knew she was going to be small, I had chalked her out on the driveway out of curiosity. When I threw a "scale me" onto the drawing, it was even smaller then I thought.
I was considering making the canopy larger for more cover from the weather, but now I'm not so sure it's a good idea.

Introducing: "Scale Man"
If you've seen any of my recent YouTube videos (Jump to 4:30), it's not a bad likeness.
At 5' 5" and 150 lbs I'm not exactly a big guy unless you live among the !Kung on the Khoikhoi.

Another designer had recommended using AGM batteries which are sort of like a jell cell. They're more durable and a lot more efficient then the automotive type wet cell batteries
I was thinking about using.
They're also a lot bigger and heavier.
We had come to the conclusion that they really wouldn't make much of a difference in a boat that wasn't trying to store power from re-charge point yesterday to re-charge point tomorrow, but now I'm thinking I may need the extra weight. It will all come down to the $ in the end.
How much will 8 RV batteries cost compared to 4 AGM's?


The "support staff" and I have been tossing around names for the craft. I wanted to go with something classic sounding like Ra or Sol but so far the only thing that's stuck is "Floating Spaghetti Monster".