The biggest disadvantage of this one is that you have to buy a Hunter!!
OK, just having fun, sailboats are very personal with regards to taste, but remember, I was able to convince Compac to install electric in a new 27!! And to me there is nothing like the traditional look of a sailboat with a real bowsprit.

There are also a couple to catamaran companies with electric/hybrid options.
Richard

--- In electricboats@..., David Goldsmith <suntreader@> wrote:

On Wed, Nov 24, 2010 at 6:12 PM, Eric <ewdysar@> wrote:

Hmmm. I just checked the Hunter website and it says the Hunter 27 waterline
length is 23'7". But that's just a minor detail... It doesn't change the
general results much.

Ah, yep I see. I was going on the numbers published by Sail in their little
write up, they've got the hull length that Hunter lists as the LWL and don't
make mention of the LWL from the Hunter spec. Either way, its still got a
pretty good water line for its LOA, of course all that changes once you
start heeling or loading it down. I seem to remember a few years ago them
selling a Hunter 26 that was the same boat but with an outboard instead of
an inboard and some pretension to trailering, but I may be fuzzy on that. I
do remember sailing our old '77 27 into St. Augustine coming back from the
Bahamas and one of the brand new Hunter 27s sailing by us and asking us
where we'd been (the Q flag was up and we had clearly been 'out there' for a
while.)

But we're obviously on the same page. BTW, the Elco drive certainly looks
sturdy, I wonder how much that unit weighs. There's a picture on the ELCO
27e brochure that is linked to the Hunter 27 spec page on the Hunter US
website.

It looks like a serious little drive doesn't it! I'd really like to get a

look inside that case.

David

Eric


--- In electricboats@... <electricboats%40yahoogroups.com>,
David Goldsmith <suntreader@> wrote:

I love it when you lay it out for us. I'd like to throw in a few points
however. The Catalina 30 actually has a shorter waterline, its listed as
25', while the Hunter 27 has a full 27' waterline and the Hunter's
displacement is listed as about 7,600 lbs, while the Catalina weighs in

at

10,200. The current Hunter 27 really isn't in the same class as the older
Hunters of that length or the Catalinas. Its more of a stretched 25

footer

than a roomy cruiser.

Those other numbers won't dramatically affect what usually works out to a
lot of factors like how the boat is loaded, the condition of the

batteries,

and the weather and sea conditions. I wouldn't put it past them to be
quoting range and speed that assume you're sailing down hill:)

I would assume, but take this with a grain of salt, that Hunter and Elco
would have this set up very well optimized and worked out. They've both

got

extensive experience and complete control over every component so they
should be able to make a good show of things. We'll know as soon as

someone

on the list buys one, any takers?

David

On Wed, Nov 24, 2010 at 3:26 PM, Eric <ewdysar@> wrote:

David,

I ran some quick numbers to see if 20 miles at 6kts is reasonable from

that

battery bank.

214Ah @ 72V = 15.4kWh
80% depth of discharge = 12.3kWh usable...

So I would believe 20nm @ 4.5kts from specific info that you posted

from

Hunter. That is very good performance from an electric conversion of

this size....

Of course, these are all estimates based on experience collected here

and

with other electric conversions. Hunter's results may vary, the only
effective way to find out is to put one of their 27e's through its

paces.

Let's hope that someone here buys one and gives a detailed performance

and

efficiency report.

Fair winds,
Eric
Marina del Rey, CA

Hi. I am resuming my conversion plans and question if building a system from scratch using as basis a Sevcon Brushless Sailboat Kit - 8.5KW () instaead of the SolidNav unit is worth the hassle. Cost is about half, but you must add the heat sink, gear reduction system and holding rails. Your input is highly appreciated.

--- In electricboats@..., "acsarfkram" <acsarfkram@> wrote:

Hi Glenn,

I bought a factory built unit from SolidNav, the Explorer model. It has a Mars motor with a Sevcon controller. I think the gear ratio is 2 to 1 maybe a bit more than 2, you should be able to find that info on their web site.

The prop I'm using is a fixed 3 blade 12x10. I would like to try a 12x11 or 12 some day as I think I would get a higher top speed. Currently I have a top speed in calm conditions of 5.7 knts. My concern is loosing the 4 knts at 20 amps, I would not sacrifice that for a higher top speed. But 4knts at 16 amps....:-)

You can see some photos in the photo section here under "Lotus Flower".

I've been running my system non stop since May of 2008 and am very pleased. Good luck with your research and possible repower.

Mark
Santa Cruz

--- In electricboats@..., "Glenn Dennis" <vega1184@> wrote:

Mark

What motor and controller do you have? Did you get it as a kit or build it your self? What gear ratio and prop are you running? Sorry for all the questions but I am trying to figure this out.

Glenn


--- In electricboats@..., "acsarfkram" <acsarfkram@> wrote:

Hi Glenn,

With my Ericson 27, (7000lbs before batteries) I have motored for 7 hrs at a draw of 20 amps. At that point I was using a small 2 blade prop that gave me 3 knts at that current draw. I now have a fixed 3 blade that gives me 4 knts at 20 amps.

During that trip I used only one of the two 48 volt 100 amp hr banks that I have. I do not know how deep I discharged that bank because I didn't have a monitor at that point. It was probably deeper than you should discharge but I did have power at that point.

I understand the theory dictates lower run times but I would be interested in what people are getting in real life.

Mark
Santa Cruz

--- In electricboats@..., "Eric" <ewdysar@> wrote:

On Wed, Nov 24, 2010 at 6:12 PM, Eric <ewdysar@...> wrote:

Hmmm. I just checked the Hunter website and it says the Hunter 27 waterline
length is 23'7". But that's just a minor detail... It doesn't change the
general results much.

Ah, yep I see. I was going on the numbers published by Sail in their little
write up, they've got the hull length that Hunter lists as the LWL and don't
make mention of the LWL from the Hunter spec. Either way, its still got a
pretty good water line for its LOA, of course all that changes once you
start heeling or loading it down. I seem to remember a few years ago them
selling a Hunter 26 that was the same boat but with an outboard instead of
an inboard and some pretension to trailering, but I may be fuzzy on that. I
do remember sailing our old '77 27 into St. Augustine coming back from the
Bahamas and one of the brand new Hunter 27s sailing by us and asking us
where we'd been (the Q flag was up and we had clearly been 'out there' for a
while.)

But we're obviously on the same page. BTW, the Elco drive certainly looks
sturdy, I wonder how much that unit weighs. There's a picture on the ELCO
27e brochure that is linked to the Hunter 27 spec page on the Hunter US
website.

It looks like a serious little drive doesn't it! I'd really like to get a

look inside that case.

David

Eric


--- In electricboats@... <electricboats%40yahoogroups.com>,
David Goldsmith <suntreader@> wrote:

I love it when you lay it out for us. I'd like to throw in a few points
however. The Catalina 30 actually has a shorter waterline, its listed as
25', while the Hunter 27 has a full 27' waterline and the Hunter's
displacement is listed as about 7,600 lbs, while the Catalina weighs in

at

10,200. The current Hunter 27 really isn't in the same class as the older
Hunters of that length or the Catalinas. Its more of a stretched 25

footer

than a roomy cruiser.

Those other numbers won't dramatically affect what usually works out to a
lot of factors like how the boat is loaded, the condition of the

batteries,

and the weather and sea conditions. I wouldn't put it past them to be
quoting range and speed that assume you're sailing down hill:)

I would assume, but take this with a grain of salt, that Hunter and Elco
would have this set up very well optimized and worked out. They've both

got

extensive experience and complete control over every component so they
should be able to make a good show of things. We'll know as soon as

someone

on the list buys one, any takers?

David

On Wed, Nov 24, 2010 at 3:26 PM, Eric <ewdysar@> wrote:

David,

I ran some quick numbers to see if 20 miles at 6kts is reasonable from

that

battery bank.

214Ah @ 72V = 15.4kWh
80% depth of discharge = 12.3kWh usable...

So I would believe 20nm @ 4.5kts from specific info that you posted

from

Hunter. That is very good performance from an electric conversion of

this size....

Of course, these are all estimates based on experience collected here

and

with other electric conversions. Hunter's results may vary, the only
effective way to find out is to put one of their 27e's through its

paces.

Let's hope that someone here buys one and gives a detailed performance

and

efficiency report.

Fair winds,
Eric
Marina del Rey, CA

Ok all, yes its jay hafner and I have been a member of this site for a couple of years not contributing until now. I have been helping Dave Tether with some information avenues like youtube (americasailingclub). You can find all you need to know on my floridasailing.com or genigreenelectric.com which is the new name for the catamaran. I need help, some opinions if they are with honor, to finish by the Miami Boat Show in Feb. We have dock space at Strictly Sail and have the boat in Marathon Marina and Boatyard marathonmarina.net We have found some things that need a lot of work and we need volunteers. I happen to know there are able bodied, retired or otherwise, men and women on this group that would love to come learn about electric conversion, see what we are doing and benefit when it's done. This is one of the all talk no play, put up or shut up statements that advice and mentoring has great value. When you read about how we are utilizing the benefits of 144V dc systems for Propulsion, Air-conditioning, Inversion to 120/240, a simple genset (for now) and later a DC genset for retrofit you will simply be amazed. If you are not amazed then that is a better reason to come down through your advice on the table and see what we can do to make it happen.
I am paying for the rooms and some food in two condos in marathon () accommodations. You will only be allowed to work 4-5 hours a day and must enjoy every sunset and/or sunrise. We are sandblasting this weekend but skills in wire, plumbing, etc are what I need. On board will be both 144V dc 250amp bank and a 1,000 amp 12V bank..50amp shore power must be installed, chargers etc..the inventor and many other guests will show up to wow you..but this is real so decide and come on board.

Hi Glenn,

I bought a factory built unit from SolidNav, the Explorer model. It has a Mars motor with a Sevcon controller. I think the gear ratio is 2 to 1 maybe a bit more than 2, you should be able to find that info on their web site.

The prop I'm using is a fixed 3 blade 12x10. I would like to try a 12x11 or 12 some day as I think I would get a higher top speed. Currently I have a top speed in calm conditions of 5.7 knts. My concern is loosing the 4 knts at 20 amps, I would not sacrifice that for a higher top speed. But 4knts at 16 amps....:-)

You can see some photos in the photo section here under "Lotus Flower".

I've been running my system non stop since May of 2008 and am very pleased. Good luck with your research and possible repower.

Mark
Santa Cruz

--- In electricboats@..., "Glenn Dennis" <vega1184@> wrote:

Mark

What motor and controller do you have? Did you get it as a kit or build it your self? What gear ratio and prop are you running? Sorry for all the questions but I am trying to figure this out.

Glenn


--- In electricboats@..., "acsarfkram" <acsarfkram@> wrote:

Hi Glenn,

With my Ericson 27, (7000lbs before batteries) I have motored for 7 hrs at a draw of 20 amps. At that point I was using a small 2 blade prop that gave me 3 knts at that current draw. I now have a fixed 3 blade that gives me 4 knts at 20 amps.

During that trip I used only one of the two 48 volt 100 amp hr banks that I have. I do not know how deep I discharged that bank because I didn't have a monitor at that point. It was probably deeper than you should discharge but I did have power at that point.

I understand the theory dictates lower run times but I would be interested in what people are getting in real life.

Mark
Santa Cruz

--- In electricboats@..., "Eric" <ewdysar@> wrote:

Ron, one of the nice points about the boat I choose was the full keel, it
protects the prop and nozzle under all but the most "what if" conditions. The
rear of the keel where the nozzle connects was flared to allow the natural flow
to the Rice nozzle. The rudder is a turbulence maker but have to have it....
Chuckle I looked at the possibility of a 2 shafted unit but the time to
build it and experiment with 2 distinctly different systems was more than I
wanted to put into the project.. Again this is not for the racers, it's for
the person that wants to milk every bit of power out of the system to be put
back into the battery bank for either propulsion or house, don't matter to me..
Ideally I want to do it all with one prop and will continue to work and
experiment to that end, if it happens, great, if it doesn't, I'll try a
different approach... Ideas and critiques anticipated. Dave K



________________________________
From: Ron <rlgravel@...>
To: electricboats@...
Sent: Thu, December 2, 2010 3:24:22 PM
Subject: [Electric Boats] Re: Converting an Albin 27



Dave, I looked at the pictures and see what you mean about a tight fit. I got
disconnected and lost a too long post (likely a good thing)it was in reply to
Eric and his usual good information. I think his post shows that the value of
power to the speed prop and the regen from that same prop are too different to
be real practical, that is why I threw out something so different.
When we built push boats we used flanking rudders, but never did anything with
kort nozzels. Looking at your rudder, I wonder how large of a nozzel would
supply close to the same control, a hydraulic or electric powered small prop
inside and the outer adjustable blades for regen. Eliminating the shaft through
the hull would allow service without dry docking. The piviot would be where your
rudder swings now, for the minds eye it would be much like an oscilating fan
(sp). The best solution for electric will not be in a single prop.
I believe the number of batteries not needed or being replaced will offset the
cost of some engineered version of this idea, in a short time.

If we have absolutly free charging, the problem will be the same,"not enough
storage capacity for the power/time factor".

The regen nozzle might be too vulnerable to damage, but maybe not. The fear of
"what might happen" has killed some good ideas.

Ron

Ron, have you ever gone to a "brain storm session", we used to have them at
Apple all the time and you could throw out any thoughts that came to mind.
This idea isn't so far fetched at all, it just needs room. I may be a little
of a maniac but I have 4 sailboats from 17 to 37 on deck so it gives me a wide
range of test platforms, love it... What does and old retired, tired inganear
do? He works on projects... chuckle Who said we have to stay
conventional?.... out of the box thoughts are accepted, at least by me..
chuckle... if you have a chance take a look at the Redeemed album, needed a
total rebuild, it would have been a reef if anyone else would have got her...
Dave K
PS: if anyone is looking for a perfect platform for a slippery electric
sailboat conversion that is a solid boat a friend of mine has one. James
Baldwin has an Alberg 30 on a trailer in southeast Georgia that would be
perfect, all the rigging and sails, just needs the interior and what ever
auxiliary power you want to put in it.. I believe he has it on his web site
www.atomvoyages.com


________________________________
From: Ron <rlgravel@...>
To: electricboats@...
Sent: Mon, November 29, 2010 2:35:15 PM
Subject: [Electric Boats] Re: Converting an Albin 27

Dave, Sorry if I posted out of context, it was a flash of mechanics and no
thought of restrictions of the present hull.
If it has any value at all, it might require a complete new boat design to make
it practical.

Ron

--- In electricboats@..., Dave Kellogg <inganear1@> wrote:

Question Ron, how much room do you have under your waterline? I only had
enough room for a 14 inch prop and a 1 inch cross section nozzle, and I had to

make some real changes in my rudder... Room is the problem.. Dave K

PS... I have some pictures in the album section.



________________________________
From: Ron <rlgravel@>
To: electricboats@...
Sent: Mon, November 29, 2010 1:58:40 PM
Subject: [Electric Boats] Re: Converting an Albin 27

Dave,
You made a great point about weight, a large mass in motion will be less
sensitive to extracting a regen value.
I'll throw out an idea, but will not try to explain in too much detail, as I
can

never say things just right.

A two function design using the nozzle you mention, a small high speed power
prop inside the nozzle and the nozzle turns as a large regen unit, having
several blades on the outside diameter that can be feathered for least
resistance when the power prop is in use, then feathered for maximum regen when

being powered by wind or current movment.
So basiclly a two prop system. Massive torque and high speed power seem to
always be on opposite ends of where they are needed.

Ron

------------------------------------

Yahoo! Groups Links

Ok all, yes its jay hafner and I have been a member of this site for a couple of years not contributing until now. I have been helping Dave Tether with some information avenues like youtube (americasailingclub). You can find all you need to know on my floridasailing.com or genigreenelectric.com which is the new name for the catamaran. I need help, some opinions if they are with honor, to finish by the Miami Boat Show in Feb. We have dock space at Strictly Sail and have the boat in Marathon Marina and Boatyard marathonmarina.net We have found some things that need a lot of work and we need volunteers. I happen to know there are able bodied, retired or otherwise, men and women on this group that would love to come learn about electric conversion, see what we are doing and benefit when it's done. This is one of the all talk no play, put up or shut up statements that advice and mentoring has great value. When you read about how we are utilizing the benefits of 144V dc systems for Propulsion, Air-conditioning, Inversion to 120/240, a simple genset (for now) and later a DC genset for retrofit you will simply be amazed. If you are not amazed then that is a better reason to come down through your advice on the table and see what we can do to make it happen.
I am paying for the rooms and some food in two condos in marathon () accommodations. You will only be allowed to work 4-5 hours a day and must enjoy every sunset and/or sunrise. We are sandblasting this weekend but skills in wire, plumbing, etc are what I need. On board will be both 144V dc 250amp bank and a 1,000 amp 12V bank..50amp shore power must be installed, chargers etc..the inventor and many other guests will show up to wow you..but this is real so decide and come on board.

Eric,
Your slip factor seems unnecessarily pessimistic, at least for driving forward. I have no experience with regen. Perhaps you are using slip factor for reverse which may simulate regen. See for estimates and formula. They suggest 6-10 percent which agrees with my experience with my Torqeedo 801 on an easily driven very light hull at nearly hull speed.
Ned

On Dec 1, 2010, at 3:03 PM, Eric wrote:

Myles, your numbers look good. I have noticed that most prop manufacturers use a 50-55% "slip" factor in determining the proper pitch for displacement auxilliary sailboats, so your 65-70% prop efficiency may be a bit optimistic for many of our conversions....


Fair winds,
Eric
Marina del Rey, CA

From: Dave Kellogg
Subject: Re: [Electric Boats] Re: more regen conversation
To: electricboats@...
Date: Wednesday, December 1, 2010, 9:10 PM

?

Regen has always been a controversial subject here on this forum and will continue depending on which position you take.. ?I personally can't give you exact percentages on what would be acceptable for all of us, it depends on what we need in our own application. ? We work with trade offs in each case and as we all experiment within our own budgets and expertise we will find the groove we can accept.. ?and the tradeoff's we can live with, so, we keep plodding along and sharing what we learn, that's what is the most exciting about this group.. ?Dave K

---

From: Eric
To: electricboats@...
Sent: Wed, December 1, 2010 3:03:43 PM
Subject: [Electric Boats] Re: more regen conversation

Myles, your numbers look good.? I have noticed that most prop manufacturers use a 50-55% "slip" factor in determining the proper pitch for displacement auxilliary sailboats, so your 65-70% prop efficiency may be a bit optimistic for many of our conversions.

One problem in tuning a prop to maximize regen will decrease it's drive efficiency.? Since I'm personally more interested in drive efficiency to maximize my powered range, then I'm will to accept less regen.? You have clearly demonstrated why regen is limited due to the different water and prop speeds, so adding 20% to regen efficiency could make a small difference, but if came at the cost of 20% drive efficiency, it looks like a losing proposition to me.? Others may think differently...

Fair winds,
Eric
Marina del Rey, CA

Myles

Thanks for the explanation.

But which would be more efficient, turning the motor faster or slower with more resistance?

Glenn

From: electricboats@... [mailto:electricboats@...]
On Behalf Of Glenn Dennis
Sent: Wednesday, December 01, 2010 10:31 AM
To: electricboats@...
Subject: [Electric Boats] Re: more regen conversation

All

I was disappointed to learn that regen would not "completely solve all
problems" ;-) But as I read the last post I wondered, has anyone tried a
different ratio for regen sort of a two speed trans, one for propulsion and
one for regeneration. Wouldn't be that hard to fab up, but would it work?
I'm inclined to think not, in that there is only so much force being exerted
against the prop by the water flow.

You could get the motor to turn faster with a small resistance or the motor
to turn slower with large resistance, which would produce more power?

Thoughts?

Glenn