Re: [bolger] Re: Electric Smoothie
Real big help, I missed these web sites in my search. As you pointed
out, they are not as easy to find as you might think. I suspect that the
low volumne/price combo puts them out of reach of a lot of potential
buyers. I will delve further.
HJ
But Info on manufacturers of props for cruisers
out, they are not as easy to find as you might think. I suspect that the
low volumne/price combo puts them out of reach of a lot of potential
buyers. I will delve further.
HJ
But Info on manufacturers of props for cruisers
> and sailors was not so easy to come by, though I did find a few.
>
> Designer Michael Kasten has a page describing their use and
> advantages at www.kastenmarine.com/CPprops.htm. There he mentions
> the Helseth and Hundested units. I also found web sites for two
> manufacturers at www.teignbridge.co.uk/special/index.htm and
> www.klatu.com/vpf/.
>
> I hope this was some help. You may also want to search for
> Controllable Pitch Propeller and Controllable Reversible Propellers.
>
>
Harry,
I thought it would be a simple search for VP props, but I was wrong.
It seems that, besides boats, they are used on airplanes, hovercraft,
MODEL airplanes, and those propulsion pods that divers use. The U.S.
Navy and Coast Guard use them. Boat designer Michael Kasten spec's
them on most of his boats. Sailboats feather them to eliminate prop
drag when sailing. Models that automatically or manually vary their
pitch are available for outboards and stern drives, but they can not
be varied remotely (from the cabin). All of this info is easily
available online. But Info on manufacturers of props for cruisers
and sailors was not so easy to come by, though I did find a few.
Designer Michael Kasten has a page describing their use and
advantages at www.kastenmarine.com/CPprops.htm. There he mentions
the Helseth and Hundested units. I also found web sites for two
manufacturers at www.teignbridge.co.uk/special/index.htm and
www.klatu.com/vpf/.
I hope this was some help. You may also want to search for
Controllable Pitch Propeller and Controllable Reversible Propellers.
Stew
I thought it would be a simple search for VP props, but I was wrong.
It seems that, besides boats, they are used on airplanes, hovercraft,
MODEL airplanes, and those propulsion pods that divers use. The U.S.
Navy and Coast Guard use them. Boat designer Michael Kasten spec's
them on most of his boats. Sailboats feather them to eliminate prop
drag when sailing. Models that automatically or manually vary their
pitch are available for outboards and stern drives, but they can not
be varied remotely (from the cabin). All of this info is easily
available online. But Info on manufacturers of props for cruisers
and sailors was not so easy to come by, though I did find a few.
Designer Michael Kasten has a page describing their use and
advantages at www.kastenmarine.com/CPprops.htm. There he mentions
the Helseth and Hundested units. I also found web sites for two
manufacturers at www.teignbridge.co.uk/special/index.htm and
www.klatu.com/vpf/.
I hope this was some help. You may also want to search for
Controllable Pitch Propeller and Controllable Reversible Propellers.
Stew
> From: Harry W. Jamesfind,
> Subject: Re: [bolger] Re: Electric Smoothie
>
> I happen to think a lot of the VP prop also. They are hard to
> and I would appreciate any sources others out there have runacross.
>Stew,
> P.S My friend's dad worked on forklifts for a living. My friend has
> told me stories of his dads homemade pontoon boat. The floor was filled
> with forklift batteries, and an outboard engine was converted to
> electric. I imagine the controls were scavenged from a forklift too.
Thanks for more on the VP prop.
Thirty years ago while planning a home built potter's wheel for my girlfriend, I was
surprised when she told me the variable speed controller would be the most expensive part
of an electric one. As an indicator of the family budget, we were living in some $45 a
month shack out in the middle of a field. So we ended up with a kick wheel, which did make
her happy.
These days, even with IC the high frequency EV controllers still cost as much or more than
the motor they are used with. ( But they are lovely. ) That's why there's such a spread in
trolling motors between the ones that are 5 speed, resistor based and continuously
variable.
Even reading the schematic is beyond me, but a knowledgeable hobbyist could build one of
several shown in Bob Brant's 'Build Your Own Electric Vehicle.'
I bet that pontoon boat was nice. Lots of capacity to carry all the lead.
Mark
I happen to think a lot of the VP prop also. They are hard to find,
and I would appreciate any sources others out there have run across.
Hj
4) My choice, a variable pitch prop. I know, the VP prop
and I would appreciate any sources others out there have run across.
Hj
4) My choice, a variable pitch prop. I know, the VP prop
> is not cheap either, but it will eliminate both the gear box and the
> electronic motor controls. It gives you infinite speed control,
> including reverse. You could start your motor in semi-nuetral and ease
> it into gear. And it could be adjusted to provide for optimum speed or
> power generation under sail. Put the VP prop on a reduced rpm motor and
> you would have a very simple system (KISS principle), with fewer parts
> to purchase and maintain.
>
> Another advantage of the VP prop would be the ability to vary your load
> on demand. By putting an amp meter on the motor you could see exactly
> how much juice the motor is drawing, and then fine tune your power usage
> by adjusting the load on your motor. Then you could: maximize your
> range; match your power consumption to your power source (genset,
> batteries, PV...); leave enough juice for your wife's appliances; find
> that sweet spot in the speed vs power spectrum; or meet some other
> singular requirement.
>
Mark,
Ahh, the Curtis PWM is pulsing the current to control motor rpm! 15KHz
is much faster that I could switch it on and off ;)
State-o-the-art is always best. I should have stated that my thoughts
were aimed at the DIYer on a budget: I was also trying to convey a
basic difference between an electric motor and an internal combustion
engine, and to give folks a little different angle on the electrics. I
guess the best comparison is that when you put a prop with too much
pitch on an I/C engine, it boggs the engine down because you have
increased the load beyond the engines design. But since electric motors
are hard wired (literally) to run at a specific rpm, they will draw
whatever amperage is required to maintain that rpm in response to the
increased load (up to a point, and assuming no interference by controls)
The variable pitch props give you the ability to infinitely change the
pitch of your prop and so change the load on your engine/motor.
Cruisers like them because they can continue to run their diesels at an
optimum rpm during varying conditions, say calm sea vs rough). The
props slip should be greater with a higher pitched prop and less with a
lower pitch (some prop guru please jump in here). But slip is not what
the VP prop uses to slow the boat down, it is the lower pitch, which at
the same time lowers the load on the motor/engine. This lower load on
your electric motor would result in a lower draw on your batteries, just
as when you lighten the load on your engine you must throttle back to
maintain the same rpm and thereby save fuel.
P.S My friend's dad worked on forklifts for a living. My friend has
told me stories of his dads homemade pontoon boat. The floor was filled
with forklift batteries, and an outboard engine was converted to
electric. I imagine the controls were scavenged from a forklift too.
Ahh, the Curtis PWM is pulsing the current to control motor rpm! 15KHz
is much faster that I could switch it on and off ;)
State-o-the-art is always best. I should have stated that my thoughts
were aimed at the DIYer on a budget: I was also trying to convey a
basic difference between an electric motor and an internal combustion
engine, and to give folks a little different angle on the electrics. I
guess the best comparison is that when you put a prop with too much
pitch on an I/C engine, it boggs the engine down because you have
increased the load beyond the engines design. But since electric motors
are hard wired (literally) to run at a specific rpm, they will draw
whatever amperage is required to maintain that rpm in response to the
increased load (up to a point, and assuming no interference by controls)
The variable pitch props give you the ability to infinitely change the
pitch of your prop and so change the load on your engine/motor.
Cruisers like them because they can continue to run their diesels at an
optimum rpm during varying conditions, say calm sea vs rough). The
props slip should be greater with a higher pitched prop and less with a
lower pitch (some prop guru please jump in here). But slip is not what
the VP prop uses to slow the boat down, it is the lower pitch, which at
the same time lowers the load on the motor/engine. This lower load on
your electric motor would result in a lower draw on your batteries, just
as when you lighten the load on your engine you must throttle back to
maintain the same rpm and thereby save fuel.
P.S My friend's dad worked on forklifts for a living. My friend has
told me stories of his dads homemade pontoon boat. The floor was filled
with forklift batteries, and an outboard engine was converted to
electric. I imagine the controls were scavenged from a forklift too.
Stew,
Thanks for the interesting read.
I have no experience with variable props, but guess the working principle might be
increasing slip. If so, it would not advantage the very tight energy constraints upon on
an eboat.
In any case, the solid state controllers have pretty much become the standard in electric
vehicles. They are not that expensive anymore-maybe come to less than all the contactors
etc. to stay with battery switching, less than rewinding motors. One to fit most eboats
is in the $500 - 1500 range. With the latter you could accelerate a car @ 120v, 300 -
500a, a load one won't go far with on the water.
These black boxes with just four connectors are pretty foolproof. They provide for more
than just soft starts. You can continuously match the load to the conditions.
With your interest in this, you might get an evening's kick from googling
http://www.google.com/search?client=googlet&q=Curtis%20PWM%20dc
Mark
Stew Miller wrote:
Thanks for the interesting read.
I have no experience with variable props, but guess the working principle might be
increasing slip. If so, it would not advantage the very tight energy constraints upon on
an eboat.
In any case, the solid state controllers have pretty much become the standard in electric
vehicles. They are not that expensive anymore-maybe come to less than all the contactors
etc. to stay with battery switching, less than rewinding motors. One to fit most eboats
is in the $500 - 1500 range. With the latter you could accelerate a car @ 120v, 300 -
500a, a load one won't go far with on the water.
These black boxes with just four connectors are pretty foolproof. They provide for more
than just soft starts. You can continuously match the load to the conditions.
With your interest in this, you might get an evening's kick from googling
http://www.google.com/search?client=googlet&q=Curtis%20PWM%20dc
Mark
Stew Miller wrote:
>
> Most electric motors have two speeds - on and off. So some sort of
> speed reduction will be required for docking and other low speed
> applications. Several options come to mind: 1) an automotive type
> transmission with multiple gear ratios (ugh!) 2) Voltage reduction
> through creative battery switching. Inexpensive, but it would only give
> a few speeds to choose from, and may require pulsing (on-off-on-off) for
> very low speed work (ugh again!). It may also require you to start your
> motor in gear, which puts a strain on your system. 3) The continuously
> variable, solid state controller mentioned by Mark would fix both of the
> speed and starting-under-load problems, but at the noted increase in
> expense ($3k just for soft-starts on the mining eq.). Plus it would add
> another point of potential failure, which could not be fixed at your
> local marina. 4) My choice, a variable pitch prop. I know, the VP prop
> is not cheap either, but it will eliminate both the gear box and the
> electronic motor controls. i
I used to design coal-mining equipment. We much preferred electric
power to diesel when the customer had a huge genset or was working near
a power line. Here's a little more food for thought on electric motors:
If you're considering getting a motor custom wound by your motor guru
(always our choice by the way), you can have him wind it to run at a
lower (than original) rpm. I recall that our options were always in
multiples of 600: 1200, 1800, 2400, 3600... DC motors may vary, but you
get the idea. If you could get a 600 rpm motor for hull speed travel,
you could eliminate the space, weight, cost and power loss of the gear
reducer.
The ratings on electrice motors are for continuous duty: the maximum
load at which the motor can run continuously without melting down.
However, electric motors only perform work equal to the load that is
placed on them. For example, if you ask your 10hp rated motor to
perform 5hp of work (the load), it will consume only enough electricity
to perform the 5hp of work (1hp = 746watts). If you run your motor with
no load, you will use almost no electricity (there is some loss due to
friction, etc). And if you ask it for 15hp, for example by using the
wrong pitch prop, it will do it - until it burns out. This can be VERY
useful, as you can call upon the motor to provide two or three times its
rated output for short periods of time (something you just can't do with
an internal combustion engine). Circuit breakers designed for electric
motors take this into account. The point is that just because you
install a 10hp motor, it doesn't mean the it will consume 10hp worth of
electricity whenever it is running.
Electric motors share one advantage with hydraulic motors: they are
small and can be located remote from the power source. This is minor,
but explains common use of electric and hydraulic motors in bow
thrusters. In primary propulsion it offers the option of relocating the
weight from the stern, as compared to typical engine installations.
Most electric motors have two speeds - on and off. So some sort of
speed reduction will be required for docking and other low speed
applications. Several options come to mind: 1) an automotive type
transmission with multiple gear ratios (ugh!) 2) Voltage reduction
through creative battery switching. Inexpensive, but it would only give
a few speeds to choose from, and may require pulsing (on-off-on-off) for
very low speed work (ugh again!). It may also require you to start your
motor in gear, which puts a strain on your system. 3) The continuously
variable, solid state controller mentioned by Mark would fix both of the
speed and starting-under-load problems, but at the noted increase in
expense ($3k just for soft-starts on the mining eq.). Plus it would add
another point of potential failure, which could not be fixed at your
local marina. 4) My choice, a variable pitch prop. I know, the VP prop
is not cheap either, but it will eliminate both the gear box and the
electronic motor controls. It gives you infinite speed control,
including reverse. You could start your motor in semi-nuetral and ease
it into gear. And it could be adjusted to provide for optimum speed or
power generation under sail. Put the VP prop on a reduced rpm motor and
you would have a very simple system (KISS principle), with fewer parts
to purchase and maintain.
Another advantage of the VP prop would be the ability to vary your load
on demand. By putting an amp meter on the motor you could see exactly
how much juice the motor is drawing, and then fine tune your power usage
by adjusting the load on your motor. Then you could: maximize your
range; match your power consumption to your power source (genset,
batteries, PV...); leave enough juice for your wife's appliances; find
that sweet spot in the speed vs power spectrum; or meet some other
singular requirement.
power to diesel when the customer had a huge genset or was working near
a power line. Here's a little more food for thought on electric motors:
If you're considering getting a motor custom wound by your motor guru
(always our choice by the way), you can have him wind it to run at a
lower (than original) rpm. I recall that our options were always in
multiples of 600: 1200, 1800, 2400, 3600... DC motors may vary, but you
get the idea. If you could get a 600 rpm motor for hull speed travel,
you could eliminate the space, weight, cost and power loss of the gear
reducer.
The ratings on electrice motors are for continuous duty: the maximum
load at which the motor can run continuously without melting down.
However, electric motors only perform work equal to the load that is
placed on them. For example, if you ask your 10hp rated motor to
perform 5hp of work (the load), it will consume only enough electricity
to perform the 5hp of work (1hp = 746watts). If you run your motor with
no load, you will use almost no electricity (there is some loss due to
friction, etc). And if you ask it for 15hp, for example by using the
wrong pitch prop, it will do it - until it burns out. This can be VERY
useful, as you can call upon the motor to provide two or three times its
rated output for short periods of time (something you just can't do with
an internal combustion engine). Circuit breakers designed for electric
motors take this into account. The point is that just because you
install a 10hp motor, it doesn't mean the it will consume 10hp worth of
electricity whenever it is running.
Electric motors share one advantage with hydraulic motors: they are
small and can be located remote from the power source. This is minor,
but explains common use of electric and hydraulic motors in bow
thrusters. In primary propulsion it offers the option of relocating the
weight from the stern, as compared to typical engine installations.
Most electric motors have two speeds - on and off. So some sort of
speed reduction will be required for docking and other low speed
applications. Several options come to mind: 1) an automotive type
transmission with multiple gear ratios (ugh!) 2) Voltage reduction
through creative battery switching. Inexpensive, but it would only give
a few speeds to choose from, and may require pulsing (on-off-on-off) for
very low speed work (ugh again!). It may also require you to start your
motor in gear, which puts a strain on your system. 3) The continuously
variable, solid state controller mentioned by Mark would fix both of the
speed and starting-under-load problems, but at the noted increase in
expense ($3k just for soft-starts on the mining eq.). Plus it would add
another point of potential failure, which could not be fixed at your
local marina. 4) My choice, a variable pitch prop. I know, the VP prop
is not cheap either, but it will eliminate both the gear box and the
electronic motor controls. It gives you infinite speed control,
including reverse. You could start your motor in semi-nuetral and ease
it into gear. And it could be adjusted to provide for optimum speed or
power generation under sail. Put the VP prop on a reduced rpm motor and
you would have a very simple system (KISS principle), with fewer parts
to purchase and maintain.
Another advantage of the VP prop would be the ability to vary your load
on demand. By putting an amp meter on the motor you could see exactly
how much juice the motor is drawing, and then fine tune your power usage
by adjusting the load on your motor. Then you could: maximize your
range; match your power consumption to your power source (genset,
batteries, PV...); leave enough juice for your wife's appliances; find
that sweet spot in the speed vs power spectrum; or meet some other
singular requirement.
I think you may find that this nozzle data only applies when your
gearing isn't low enough and the prop is too small, and for initial
acceleration. Of course those may be constraints you have on your
design already. A nozzle will be hard to build, tho.
gearing isn't low enough and the prop is too small, and for initial
acceleration. Of course those may be constraints you have on your
design already. A nozzle will be hard to build, tho.
--- In bolger@y..., "announcer97624" <cupp@k...> wrote:
> --- In bolger@y..., "recree8" <arvent@h...> wrote:
>snip
>
> I am going to talk with one of the engineers at a leading nozzle
> company when I get the specs on the motor and shaft size to get a
> recommendation on the nozzle and prop size. Depending on the design
> of the nozzle and propeller you can increase performance by 35% as
> opposed to a propeller without a nozzle. On the plus side the nozzle
> increase thrust and protects the prop. The negative side is that at
> hull planning speeds the nozzle drag nullified the thrust increase.
>
snip
--- In bolger@y..., "recree8" <arvent@h...> wrote:
and he told me my idea of a submersible AC pump motor reworked by him
with a speed rheostat battery/genset/ photovoltaic power source is
very do-able. He also told me that the most expensive part(next to
the genset and photovoltaic panels) will be the converter for DC to
AC, it should cost about $1,500 US. He claims to me that can build a
10 HP unit that can be reversed and since it will be submerged for
cooling he will give it a ten year warranty. He also said with the
new battery conditioners they have come out with batteries should
last that long or longer now.
I am going to talk with one of the engineers at a leading nozzle
company when I get the specs on the motor and shaft size to get a
recommendation on the nozzle and prop size. Depending on the design
of the nozzle and propeller you can increase performance by 35% as
opposed to a propeller without a nozzle. On the plus side the nozzle
increase thrust and protects the prop. The negative side is that at
hull planning speeds the nozzle drag nullified the thrust increase.
Since most of us are just out for a nice cruise and we don't really
need a twenty foot rooster tail behind our boats the nozzle increases
performance and thrust in low to medium speed applications. Just
where most of us need the power. With a 10 HP reversible submerged
motor it should be the answer to some of our wishes.
A few links to ponder besides the Solomon pages.
http://www.feys.org/System/our_system.htm
http://www.marineengine.com/cgi-bin/links/jump.cgi?ID=325
> Thanks for the info Mark. The 8 HP looks about doable. Instead ofof
> four 6 volt batteries, one would need four 24 volt batteries which
> course are just four 6 volt batteries each:-) It's interesting thatGentlemen I spoke with my local electric engineer/motor rebuilder
> once one figures out all the regulators and transformers and then
> some kind of tranmission - gee whiz it hardly seems worth it. Might
> just as well use an outboard for motoring and a genset for all the
> live aboard stuff! No - not that I've quit scheming yet!
>
> Nels
and he told me my idea of a submersible AC pump motor reworked by him
with a speed rheostat battery/genset/ photovoltaic power source is
very do-able. He also told me that the most expensive part(next to
the genset and photovoltaic panels) will be the converter for DC to
AC, it should cost about $1,500 US. He claims to me that can build a
10 HP unit that can be reversed and since it will be submerged for
cooling he will give it a ten year warranty. He also said with the
new battery conditioners they have come out with batteries should
last that long or longer now.
I am going to talk with one of the engineers at a leading nozzle
company when I get the specs on the motor and shaft size to get a
recommendation on the nozzle and prop size. Depending on the design
of the nozzle and propeller you can increase performance by 35% as
opposed to a propeller without a nozzle. On the plus side the nozzle
increase thrust and protects the prop. The negative side is that at
hull planning speeds the nozzle drag nullified the thrust increase.
Since most of us are just out for a nice cruise and we don't really
need a twenty foot rooster tail behind our boats the nozzle increases
performance and thrust in low to medium speed applications. Just
where most of us need the power. With a 10 HP reversible submerged
motor it should be the answer to some of our wishes.
A few links to ponder besides the Solomon pages.
http://www.feys.org/System/our_system.htm
http://www.marineengine.com/cgi-bin/links/jump.cgi?ID=325
Thanks for the info Mark. The 8 HP looks about doable. Instead of
four 6 volt batteries, one would need four 24 volt batteries which of
course are just four 6 volt batteries each:-) It's interesting that
once one figures out all the regulators and transformers and then
some kind of tranmission - gee whiz it hardly seems worth it. Might
just as well use an outboard for motoring and a genset for all the
live aboard stuff! No - not that I've quit scheming yet!
Nels
four 6 volt batteries, one would need four 24 volt batteries which of
course are just four 6 volt batteries each:-) It's interesting that
once one figures out all the regulators and transformers and then
some kind of tranmission - gee whiz it hardly seems worth it. Might
just as well use an outboard for motoring and a genset for all the
live aboard stuff! No - not that I've quit scheming yet!
Nels
--- In bolger@y..., Mark Albanese <marka@h...> wrote:
>
>
> rnlocnil wrote:
> >
> > I wonder what a regular or scrounged electric motor would cost
and if
> > it would work. (We are a bunch of mostly impecunious Bolgerites,
of
> > course, so you have to expect this reaction.)
>
> Just about anything will do for an inboard, including a surplus
aircraft starter motor if
> you're not too hard on it. On the other hand, even a new, designed
for EV use, Advanced DC
> in the 2 - 20 hp ( continuous ) range are, respectively, 375 -
1200 dollars, plus about
> the same if you want a continuously variable, solid state
controller.
>http://www.kta-ev.com/catalog/index.html
>
> The impecunious might revert to battery switching to change the
voltage in a couple of
> steps; say half, and then full power.
> >
> > >From the figures you provide, efficiency on the Stirling genset
is
> > somewhat low, and I bet you wouldn't get very good mileage under
> > power.
>
> Correct!
>
> Mark
The Whispergen puts out up to 6KW of heat per hour burning .18
gallons of diesel per hour. That's 90 percent efficiency. It's
exhaust is only 70C/180F. It's really a furnace that happens to
produce enough power in a day to run everything else, verrry quietly.
My energy budget even allows for an air-conditioner (450 watts,
intermittent)in the summer!
Since the boat is an auxillary, I don't want to run the motor
continuously. If I drive it at 5 knots, that would require half power
of the ST37 at about 2.7 KW per hour and I should be able to clear
moorages just fine since one of those battery banks stores 30 KW. If
my wife really means it when she say that she doesn't need a lot of
electric appliances If I was in a hurry to get somewhere, why would I
bother with sails or, even, a boat?
The boat, BTW, is meant to be something of a cross between LM2 and
Solution 48. Shallow draft, steel, retractable appendages above and
below.
gallons of diesel per hour. That's 90 percent efficiency. It's
exhaust is only 70C/180F. It's really a furnace that happens to
produce enough power in a day to run everything else, verrry quietly.
My energy budget even allows for an air-conditioner (450 watts,
intermittent)in the summer!
Since the boat is an auxillary, I don't want to run the motor
continuously. If I drive it at 5 knots, that would require half power
of the ST37 at about 2.7 KW per hour and I should be able to clear
moorages just fine since one of those battery banks stores 30 KW. If
my wife really means it when she say that she doesn't need a lot of
electric appliances If I was in a hurry to get somewhere, why would I
bother with sails or, even, a boat?
The boat, BTW, is meant to be something of a cross between LM2 and
Solution 48. Shallow draft, steel, retractable appendages above and
below.
--- In bolger@y..., "rnlocnil" <lincolnr@m...> wrote:
> From the figures you provide, efficiency on the Stirling genset is
> somewhat low, and I bet you wouldn't get very good mileage under
> power. I wonder what comparable figures would be for a piston IC
> engine with a heat exchanger in the exhaust? Of course it would be
> noisier. You won't be able to motor at high power settings
> continuously.
>
Dick
rnlocnil wrote:
you're not too hard on it. On the other hand, even a new, designed for EV use, Advanced DC
in the 2 - 20 hp ( continuous ) range are, respectively, 375 - 1200 dollars, plus about
the same if you want a continuously variable, solid state controller.
http://www.kta-ev.com/catalog/index.html
The impecunious might revert to battery switching to change the voltage in a couple of
steps; say half, and then full power.
Mark
>Just about anything will do for an inboard, including a surplus aircraft starter motor if
> I wonder what a regular or scrounged electric motor would cost and if
> it would work. (We are a bunch of mostly impecunious Bolgerites, of
> course, so you have to expect this reaction.)
you're not too hard on it. On the other hand, even a new, designed for EV use, Advanced DC
in the 2 - 20 hp ( continuous ) range are, respectively, 375 - 1200 dollars, plus about
the same if you want a continuously variable, solid state controller.
http://www.kta-ev.com/catalog/index.html
The impecunious might revert to battery switching to change the voltage in a couple of
steps; say half, and then full power.
>Correct!
> >From the figures you provide, efficiency on the Stirling genset is
> somewhat low, and I bet you wouldn't get very good mileage under
> power.
Mark
I'm impressed that Solomon is honest enough to warn you about losing
the 3/4 knot. THat's a fair amount of drag. If you could figure out a
way to feather or fold the drive prop and engage a prop designed for
this function, I bet you could have much less drag when regenerating.
I wonder what a regular or scrounged electric motor would cost and if
it would work. (We are a bunch of mostly impecunious Bolgerites, of
course, so you have to expect this reaction.)
From the figures you provide, efficiency on the Stirling genset is
somewhat low, and I bet you wouldn't get very good mileage under
power. I wonder what comparable figures would be for a piston IC
engine with a heat exchanger in the exhaust? Of course it would be
noisier. You won't be able to motor at high power settings
continuously.
the 3/4 knot. THat's a fair amount of drag. If you could figure out a
way to feather or fold the drive prop and engage a prop designed for
this function, I bet you could have much less drag when regenerating.
I wonder what a regular or scrounged electric motor would cost and if
it would work. (We are a bunch of mostly impecunious Bolgerites, of
course, so you have to expect this reaction.)
From the figures you provide, efficiency on the Stirling genset is
somewhat low, and I bet you wouldn't get very good mileage under
power. I wonder what comparable figures would be for a piston IC
engine with a heat exchanger in the exhaust? Of course it would be
noisier. You won't be able to motor at high power settings
continuously.
--- In bolger@y..., "dickpilz" <dickpilz@g...> wrote:
> My current dream is to have the auxillary power for a sharpie thus:
>
> Turning the prop:
>
>http://www.solomontechnologies.com/
>
> These electric motors have already prven themselves. The downside is
> approximately one kilobuck (US) per HP. The 6 HP would do me nicely,
> though. And, it regenerates under sail!
>
snip
> And for the genset:
>
>http://www.whispertech.co.nz/
>
> These enclosed Stirling Engine gensets put out .75 KW electric, 6 KW
> hot water/heat (I live on the Upper Left Coast and this is a
> necessity) 24 x 7 for 5000 hours, burner nozzle cleaning and 50,000
> hours between overhauls. Again, you pay for what you get and these
> puppies cost 10 kilobucks. As a source of power AND heat this is
> still competitive.
>
> As a system, this should be reliable and quiet. The initial cost
> impact is lessened when I consider this to be a retirement home.
>
> Dick
Dick,
You're thinking first rate, and with with the requisite deep pockets.
I do note the ST motor is recommended at 144 volts. This might consume the available amps
in either of your proposed battery banks pretty quickly. Apart from the ( arguable )
benefit of regen under sail, why this rather than a good, primary drive outboard or, to
stay top of the line, a SolZ saildrive?
It's pretty easy to have 6 hp at 48 volts, leaving a lot of lead to combine for amperage.
But 6 hp ( electric ) is about the right hull speed power for a 3000# boat. If you're
batteries are half the all up weight, how can anyone retire on a boat the size of Martha
Jane ( assuming, wrongly, it could carry the weight) ?
I guess if your strictly thinking auxiliary, and drop down to 1 hp per 1000, then you
could have about a bare bones, 80 sheet boat + batteries in the 6000 pound range. On a 40'
waterline, it looks like 6.5 kt. That'll work.
Mark
dickpilz wrote:
You're thinking first rate, and with with the requisite deep pockets.
I do note the ST motor is recommended at 144 volts. This might consume the available amps
in either of your proposed battery banks pretty quickly. Apart from the ( arguable )
benefit of regen under sail, why this rather than a good, primary drive outboard or, to
stay top of the line, a SolZ saildrive?
It's pretty easy to have 6 hp at 48 volts, leaving a lot of lead to combine for amperage.
But 6 hp ( electric ) is about the right hull speed power for a 3000# boat. If you're
batteries are half the all up weight, how can anyone retire on a boat the size of Martha
Jane ( assuming, wrongly, it could carry the weight) ?
I guess if your strictly thinking auxiliary, and drop down to 1 hp per 1000, then you
could have about a bare bones, 80 sheet boat + batteries in the 6000 pound range. On a 40'
waterline, it looks like 6.5 kt. That'll work.
Mark
dickpilz wrote:
>
> My current dream is to have the auxillary power for a sharpie thus:
>
> Turning the prop:
>
>http://www.solomontechnologies.com/
>
> These electric motors have already prven themselves. The downside is
> approximately one kilobuck (US) per HP. The 6 HP would do me nicely,
> though. And, it regenerates under sail!
>
> The battery bank:
>
>http://www.lifelinebatteries.com/marinebattery.asp
>
> These batteries are AGP style that don't leak at any angle, don't
> leak even if punctured and are deep-cycle lead-acid, so they won't
> have to be replaced very often. A good thing, because they cost about
> 2.50 USD per pound and I will need about 1600 pounds of them. Twice
> as much if I decide to have two banks. Good internal ballast.
>
> And for the genset:
>
>http://www.whispertech.co.nz/
>
> These enclosed Stirling Engine gensets put out .75 KW electric, 6 KW
> hot water/heat (I live on the Upper Left Coast and this is a
> necessity) 24 x 7 for 5000 hours, burner nozzle cleaning and 50,000
> hours between overhauls. Again, you pay for what you get and these
> puppies cost 10 kilobucks. As a source of power AND heat this is
> still competitive.
>
> As a system, this should be reliable and quiet. The initial cost
> impact is lessened when I consider this to be a retirement home.
>
> Dick
My current dream is to have the auxillary power for a sharpie thus:
Turning the prop:
http://www.solomontechnologies.com/
These electric motors have already prven themselves. The downside is
approximately one kilobuck (US) per HP. The 6 HP would do me nicely,
though. And, it regenerates under sail!
The battery bank:
http://www.lifelinebatteries.com/marinebattery.asp
These batteries are AGP style that don't leak at any angle, don't
leak even if punctured and are deep-cycle lead-acid, so they won't
have to be replaced very often. A good thing, because they cost about
2.50 USD per pound and I will need about 1600 pounds of them. Twice
as much if I decide to have two banks. Good internal ballast.
And for the genset:
http://www.whispertech.co.nz/
These enclosed Stirling Engine gensets put out .75 KW electric, 6 KW
hot water/heat (I live on the Upper Left Coast and this is a
necessity) 24 x 7 for 5000 hours, burner nozzle cleaning and 50,000
hours between overhauls. Again, you pay for what you get and these
puppies cost 10 kilobucks. As a source of power AND heat this is
still competitive.
As a system, this should be reliable and quiet. The initial cost
impact is lessened when I consider this to be a retirement home.
Dick
Turning the prop:
http://www.solomontechnologies.com/
These electric motors have already prven themselves. The downside is
approximately one kilobuck (US) per HP. The 6 HP would do me nicely,
though. And, it regenerates under sail!
The battery bank:
http://www.lifelinebatteries.com/marinebattery.asp
These batteries are AGP style that don't leak at any angle, don't
leak even if punctured and are deep-cycle lead-acid, so they won't
have to be replaced very often. A good thing, because they cost about
2.50 USD per pound and I will need about 1600 pounds of them. Twice
as much if I decide to have two banks. Good internal ballast.
And for the genset:
http://www.whispertech.co.nz/
These enclosed Stirling Engine gensets put out .75 KW electric, 6 KW
hot water/heat (I live on the Upper Left Coast and this is a
necessity) 24 x 7 for 5000 hours, burner nozzle cleaning and 50,000
hours between overhauls. Again, you pay for what you get and these
puppies cost 10 kilobucks. As a source of power AND heat this is
still competitive.
As a system, this should be reliable and quiet. The initial cost
impact is lessened when I consider this to be a retirement home.
Dick