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  #121   Report Post  
Jeff Morris
 
Posts: n/a
Default

Many boats do. Mine came with folders. Many (most?) of the JBoats come with
folders or feathering props.

But this was 10% over a 3-blade at high speed; the drag for a 2-blade at
moderate speed is somewhat less. And there are downsides to folders and
feathering props, such as reverse thrust, cost, reliability. They are not for
everyone, but they are certainly a reasonable option for many cruisers.



"JAXAshby" wrote in message
...
jeffies, if folding/feathering/kinda twisting props increased performance by
your claimed 10% ALL new boats would have them installed at the factory.

duh.

From: "Jeff Morris"
Date: 9/5/2004 10:55 AM Eastern Daylight Time
Message-id:

Time for the meds again, jaxie. Your reading comprehension is failing. I
made
no claim of the Westsail, I said "At the low RPMs many boats use to go 5
knots,
they only use 10 to 12 hp to go forward." Are you claiming that a Westsail
is
representative of "many boats"?

If fact, I already said several times that I didn't think a low drag prop
would
help a Westsail that much, but they could be of value to many other boats.
You've been claiming that they are useless for any boat other than a high
performance racer. Since you lost that argument, you're now backpedaling and
misrepresenting my comments. Typical lying from cowardly jaxie.

But, since you brought it up, how much power does a Westsail actually use?
At
5 knots, that is a "Speed to Length" ratio of 0.95 (where the 7 knot hull
speed
would be 1.34). To achieve that speed, a displacement boat will have 1400
pounds per HP. At 20,000 pounds, the Westsail uses about 14.2 HP. A bit
higher than the "10 to 12" I mentioned for "many boats," but most 32 footers
don't weigh anywhere near 10 tons. How much wind is needed to generate 14
hp
on a Westsail? With 650 square feet of sail, assuming 0.02 HP/sq.ft. at 14
knots wind, this is 13 HP; so it looks like about 15 to 16 knots of wind is
needed to get a Westsail up to 5 knots.





"JAXAshby" wrote in message
...
jeffies, **you** claimed it only takes 10 or 12 hp to push a Westsail 32 at
five knots. remember? nah, I am sure you don't remember anything from

more
than 7 hours ago.

From: "Jeff Morris"

Date: 9/4/2004 11:11 PM Eastern Daylight Time
Message-id:

"JAXAshby" wrote in message
...
jeffies, a boat under sail has one hell of a lot more drag than a boat
motoring
in a flat calm.

And how is this relevant to anything?



also, keep in mind that the boat under discussion is a Westsail 32, a

boat
usually having a minimum of 30 hp installed, and often 40+ hp.

A Westsail 32 with a 10 to 12 hp engine installed is unmarketable. One
would
need one hell of a lot patience to wait for wind and tide before setting
off.

Are you claiming that an aux engine is always run at an rpm that produces

its
full rated power? Most boaters understand that a diesel might only

produce
half
its rated output at cruise speed. For example, a Yanmar 3YM is rated at

29
HP
only delivers about 14 to the prop at 2800 rpm.

Although the OP has a Westsail, he asked what other boaters have

experienced,
so
the discussion is about all boats. As I said elsewhere, I think the

Westsail
would benefit less than other boats from a low drag prop.






keep in mind that props don't drag all that much anyway. according

to
the
MIT
data, even a fixed 3 blade only pulled 170# on a boat at 5 knots, or
about
the
equivelent of 2-1/2 hp.


That's not much drag??? That's roughly the drag from a 25 knot

breeze!
Are
you saying that this would have no affect on boat speed?

Are you claiming that a having a 2.5 hp engine pulling backwards would
have
little affect on speed? At the low RPMs many boats use to go 5 knots,
they
only
use 10 to 12 hp to go forward
































  #122   Report Post  
Jeff Morris
 
Posts: n/a
Default

jaxie, even my cat understands that you changed the thread by claiming the
folders "only have value for racing boats." Now that you've been proven wrong
on that, you're backpedaling as fast as you can. Don't hurt yourself.



"JAXAshby" wrote in message
...
jeffies, the discussion has from the start been about a Westsail 32. ask your
wife to reread the posts for you.

From: "Jeff Morris"
Date: 9/5/2004 10:55 AM Eastern Daylight Time
Message-id:

Time for the meds again, jaxie. Your reading comprehension is failing. I
made
no claim of the Westsail, I said "At the low RPMs many boats use to go 5
knots,
they only use 10 to 12 hp to go forward." Are you claiming that a Westsail
is
representative of "many boats"?

If fact, I already said several times that I didn't think a low drag prop
would
help a Westsail that much, but they could be of value to many other boats.
You've been claiming that they are useless for any boat other than a high
performance racer. Since you lost that argument, you're now backpedaling and
misrepresenting my comments. Typical lying from cowardly jaxie.

But, since you brought it up, how much power does a Westsail actually use?
At
5 knots, that is a "Speed to Length" ratio of 0.95 (where the 7 knot hull
speed
would be 1.34). To achieve that speed, a displacement boat will have 1400
pounds per HP. At 20,000 pounds, the Westsail uses about 14.2 HP. A bit
higher than the "10 to 12" I mentioned for "many boats," but most 32 footers
don't weigh anywhere near 10 tons. How much wind is needed to generate 14
hp
on a Westsail? With 650 square feet of sail, assuming 0.02 HP/sq.ft. at 14
knots wind, this is 13 HP; so it looks like about 15 to 16 knots of wind is
needed to get a Westsail up to 5 knots.





"JAXAshby" wrote in message
...
jeffies, **you** claimed it only takes 10 or 12 hp to push a Westsail 32 at
five knots. remember? nah, I am sure you don't remember anything from

more
than 7 hours ago.

From: "Jeff Morris"

Date: 9/4/2004 11:11 PM Eastern Daylight Time
Message-id:

"JAXAshby" wrote in message
...
jeffies, a boat under sail has one hell of a lot more drag than a boat
motoring
in a flat calm.

And how is this relevant to anything?



also, keep in mind that the boat under discussion is a Westsail 32, a

boat
usually having a minimum of 30 hp installed, and often 40+ hp.

A Westsail 32 with a 10 to 12 hp engine installed is unmarketable. One
would
need one hell of a lot patience to wait for wind and tide before setting
off.

Are you claiming that an aux engine is always run at an rpm that produces

its
full rated power? Most boaters understand that a diesel might only

produce
half
its rated output at cruise speed. For example, a Yanmar 3YM is rated at

29
HP
only delivers about 14 to the prop at 2800 rpm.

Although the OP has a Westsail, he asked what other boaters have

experienced,
so
the discussion is about all boats. As I said elsewhere, I think the

Westsail
would benefit less than other boats from a low drag prop.






keep in mind that props don't drag all that much anyway. according

to
the
MIT
data, even a fixed 3 blade only pulled 170# on a boat at 5 knots, or
about
the
equivelent of 2-1/2 hp.


That's not much drag??? That's roughly the drag from a 25 knot

breeze!
Are
you saying that this would have no affect on boat speed?

Are you claiming that a having a 2.5 hp engine pulling backwards would
have
little affect on speed? At the low RPMs many boats use to go 5 knots,
they
only
use 10 to 12 hp to go forward
































  #123   Report Post  
JAXAshby
 
Posts: n/a
Default

jeffies, attempting rational discussion with you is attempting rational
discussion with the village idiot. you just smile and chew on flower picked
from the hedge.

btw, jeffies, what everyone else is fully aware of and you are totally ignorant
of is that folding/feathering prop manufacturers promote their products' value
at ---- low ---- wind speeds, not high speeds.

duh.


From: "Jeff Morris"
Date: 9/5/2004 3:09 PM Eastern Daylight Time
Message-id:

jaxie, even my cat understands that you changed the thread by claiming the
folders "only have value for racing boats." Now that you've been proven
wrong
on that, you're backpedaling as fast as you can. Don't hurt yourself.



"JAXAshby" wrote in message
...
jeffies, the discussion has from the start been about a Westsail 32. ask

your
wife to reread the posts for you.

From: "Jeff Morris"

Date: 9/5/2004 10:55 AM Eastern Daylight Time
Message-id:

Time for the meds again, jaxie. Your reading comprehension is failing.

I
made
no claim of the Westsail, I said "At the low RPMs many boats use to go 5
knots,
they only use 10 to 12 hp to go forward." Are you claiming that a

Westsail
is
representative of "many boats"?

If fact, I already said several times that I didn't think a low drag prop
would
help a Westsail that much, but they could be of value to many other boats.
You've been claiming that they are useless for any boat other than a high
performance racer. Since you lost that argument, you're now backpedaling

and
misrepresenting my comments. Typical lying from cowardly jaxie.

But, since you brought it up, how much power does a Westsail actually use?
At
5 knots, that is a "Speed to Length" ratio of 0.95 (where the 7 knot hull
speed
would be 1.34). To achieve that speed, a displacement boat will have 1400
pounds per HP. At 20,000 pounds, the Westsail uses about 14.2 HP. A bit
higher than the "10 to 12" I mentioned for "many boats," but most 32

footers
don't weigh anywhere near 10 tons. How much wind is needed to generate

14
hp
on a Westsail? With 650 square feet of sail, assuming 0.02 HP/sq.ft. at

14
knots wind, this is 13 HP; so it looks like about 15 to 16 knots of wind

is
needed to get a Westsail up to 5 knots.





"JAXAshby" wrote in message
...
jeffies, **you** claimed it only takes 10 or 12 hp to push a Westsail 32

at
five knots. remember? nah, I am sure you don't remember anything from
more
than 7 hours ago.

From: "Jeff Morris"

Date: 9/4/2004 11:11 PM Eastern Daylight Time
Message-id:

"JAXAshby" wrote in message
...
jeffies, a boat under sail has one hell of a lot more drag than a

boat
motoring
in a flat calm.

And how is this relevant to anything?



also, keep in mind that the boat under discussion is a Westsail 32, a
boat
usually having a minimum of 30 hp installed, and often 40+ hp.

A Westsail 32 with a 10 to 12 hp engine installed is unmarketable.

One
would
need one hell of a lot patience to wait for wind and tide before

setting
off.

Are you claiming that an aux engine is always run at an rpm that

produces
its
full rated power? Most boaters understand that a diesel might only
produce
half
its rated output at cruise speed. For example, a Yanmar 3YM is rated

at
29
HP
only delivers about 14 to the prop at 2800 rpm.

Although the OP has a Westsail, he asked what other boaters have
experienced,
so
the discussion is about all boats. As I said elsewhere, I think the
Westsail
would benefit less than other boats from a low drag prop.






keep in mind that props don't drag all that much anyway.

according
to
the
MIT
data, even a fixed 3 blade only pulled 170# on a boat at 5 knots,

or
about
the
equivelent of 2-1/2 hp.


That's not much drag??? That's roughly the drag from a 25 knot
breeze!
Are
you saying that this would have no affect on boat speed?

Are you claiming that a having a 2.5 hp engine pulling backwards

would
have
little affect on speed? At the low RPMs many boats use to go 5

knots,
they
only
use 10 to 12 hp to go forward








































  #124   Report Post  
Jeff Morris
 
Posts: n/a
Default

oh poor jaxie, the jealousy is just dripping off him now!


"JAXAshby" wrote in message
...
I've had little problem in reverse. But
then, I have two diesels


jeffies, your props don't give a rat's what fuel your engines burn. In fact,
your props are totally unable to determine what fuel your engines use.

so, pray tell, why do **you** think your props can tell the difference.




  #125   Report Post  
JAXAshby
 
Posts: n/a
Default

oh poor jaxie, the jealousy is just dripping off him now!

what jealousy is that, jeffies?



"JAXAshby" wrote in message
...
I've had little problem in reverse. But
then, I have two diesels


jeffies, your props don't give a rat's what fuel your engines burn. In

fact,
your props are totally unable to determine what fuel your engines use.

so, pray tell, why do **you** think your props can tell the difference.














  #126   Report Post  
Jeff Morris
 
Posts: n/a
Default

Some salesman might have tried to sell you on low speed performance because he
knew you were scared of high performance boats, but the drag of fixed props at
low speeds is not that great. Its only really significant at higher speeds. As
everyone else knows, appendage drag goes up with the square of speed.

Perhaps you can show us even one folding/feathering manufacturer's site that
claims the primary advantage is a low speed.


"JAXAshby" wrote in message
...
btw, jeffies, what everyone else is fully aware of and you are totally

ignorant
of is that folding/feathering prop manufacturers promote their products' value
at ---- low ---- wind speeds, not high speeds.

duh.


From: "Jeff Morris"
Date: 9/5/2004 3:09 PM Eastern Daylight Time
Message-id:

jaxie, even my cat understands that you changed the thread by claiming the
folders "only have value for racing boats." Now that you've been proven
wrong
on that, you're backpedaling as fast as you can. Don't hurt yourself.



"JAXAshby" wrote in message
...
jeffies, the discussion has from the start been about a Westsail 32. ask

your
wife to reread the posts for you.

From: "Jeff Morris"

Date: 9/5/2004 10:55 AM Eastern Daylight Time
Message-id:

Time for the meds again, jaxie. Your reading comprehension is failing.

I
made
no claim of the Westsail, I said "At the low RPMs many boats use to go 5
knots,
they only use 10 to 12 hp to go forward." Are you claiming that a

Westsail
is
representative of "many boats"?

If fact, I already said several times that I didn't think a low drag prop
would
help a Westsail that much, but they could be of value to many other boats.
You've been claiming that they are useless for any boat other than a high
performance racer. Since you lost that argument, you're now backpedaling

and
misrepresenting my comments. Typical lying from cowardly jaxie.

But, since you brought it up, how much power does a Westsail actually use?
At
5 knots, that is a "Speed to Length" ratio of 0.95 (where the 7 knot hull
speed
would be 1.34). To achieve that speed, a displacement boat will have 1400
pounds per HP. At 20,000 pounds, the Westsail uses about 14.2 HP. A bit
higher than the "10 to 12" I mentioned for "many boats," but most 32

footers
don't weigh anywhere near 10 tons. How much wind is needed to generate

14
hp
on a Westsail? With 650 square feet of sail, assuming 0.02 HP/sq.ft. at

14
knots wind, this is 13 HP; so it looks like about 15 to 16 knots of wind

is
needed to get a Westsail up to 5 knots.





"JAXAshby" wrote in message
...
jeffies, **you** claimed it only takes 10 or 12 hp to push a Westsail 32

at
five knots. remember? nah, I am sure you don't remember anything from
more
than 7 hours ago.

From: "Jeff Morris"

Date: 9/4/2004 11:11 PM Eastern Daylight Time
Message-id:

"JAXAshby" wrote in message
...
jeffies, a boat under sail has one hell of a lot more drag than a

boat
motoring
in a flat calm.

And how is this relevant to anything?



also, keep in mind that the boat under discussion is a Westsail 32, a
boat
usually having a minimum of 30 hp installed, and often 40+ hp.

A Westsail 32 with a 10 to 12 hp engine installed is unmarketable.

One
would
need one hell of a lot patience to wait for wind and tide before

setting
off.

Are you claiming that an aux engine is always run at an rpm that

produces
its
full rated power? Most boaters understand that a diesel might only
produce
half
its rated output at cruise speed. For example, a Yanmar 3YM is rated

at
29
HP
only delivers about 14 to the prop at 2800 rpm.

Although the OP has a Westsail, he asked what other boaters have
experienced,
so
the discussion is about all boats. As I said elsewhere, I think the
Westsail
would benefit less than other boats from a low drag prop.






keep in mind that props don't drag all that much anyway.

according
to
the
MIT
data, even a fixed 3 blade only pulled 170# on a boat at 5 knots,

or
about
the
equivelent of 2-1/2 hp.


That's not much drag??? That's roughly the drag from a 25 knot
breeze!
Are
you saying that this would have no affect on boat speed?

Are you claiming that a having a 2.5 hp engine pulling backwards

would
have
little affect on speed? At the low RPMs many boats use to go 5

knots,
they
only
use 10 to 12 hp to go forward










































  #127   Report Post  
JAXAshby
 
Posts: n/a
Default

the drag of fixed props at
low speeds is not that great.


yup.

but that is the market feathering props aim at. at the high end, just a teeny
bit more sail pushes the boat faster than you wanna go anyway.



From: "Jeff Morris"
Date: 9/5/2004 9:55 PM Eastern Daylight Time
Message-id:

Some salesman might have tried to sell you on low speed performance because
he
knew you were scared of high performance boats, but the drag of fixed props
at
low speeds is not that great. Its only really significant at higher speeds.
As
everyone else knows, appendage drag goes up with the square of speed.

Perhaps you can show us even one folding/feathering manufacturer's site that
claims the primary advantage is a low speed.


"JAXAshby" wrote in message
...
btw, jeffies, what everyone else is fully aware of and you are totally

ignorant
of is that folding/feathering prop manufacturers promote their products'

value
at ---- low ---- wind speeds, not high speeds.

duh.


From: "Jeff Morris"

Date: 9/5/2004 3:09 PM Eastern Daylight Time
Message-id:

jaxie, even my cat understands that you changed the thread by claiming the
folders "only have value for racing boats." Now that you've been proven
wrong
on that, you're backpedaling as fast as you can. Don't hurt yourself.



"JAXAshby" wrote in message
...
jeffies, the discussion has from the start been about a Westsail 32.

ask
your
wife to reread the posts for you.

From: "Jeff Morris"

Date: 9/5/2004 10:55 AM Eastern Daylight Time
Message-id:

Time for the meds again, jaxie. Your reading comprehension is failing.
I
made
no claim of the Westsail, I said "At the low RPMs many boats use to go

5
knots,
they only use 10 to 12 hp to go forward." Are you claiming that a
Westsail
is
representative of "many boats"?

If fact, I already said several times that I didn't think a low drag

prop
would
help a Westsail that much, but they could be of value to many other

boats.
You've been claiming that they are useless for any boat other than a

high
performance racer. Since you lost that argument, you're now

backpedaling
and
misrepresenting my comments. Typical lying from cowardly jaxie.

But, since you brought it up, how much power does a Westsail actually

use?
At
5 knots, that is a "Speed to Length" ratio of 0.95 (where the 7 knot

hull
speed
would be 1.34). To achieve that speed, a displacement boat will have

1400
pounds per HP. At 20,000 pounds, the Westsail uses about 14.2 HP. A

bit
higher than the "10 to 12" I mentioned for "many boats," but most 32
footers
don't weigh anywhere near 10 tons. How much wind is needed to

generate
14
hp
on a Westsail? With 650 square feet of sail, assuming 0.02 HP/sq.ft.

at
14
knots wind, this is 13 HP; so it looks like about 15 to 16 knots of

wind
is
needed to get a Westsail up to 5 knots.





"JAXAshby" wrote in message
...
jeffies, **you** claimed it only takes 10 or 12 hp to push a Westsail

32
at
five knots. remember? nah, I am sure you don't remember anything

from
more
than 7 hours ago.

From: "Jeff Morris"

Date: 9/4/2004 11:11 PM Eastern Daylight Time
Message-id:

"JAXAshby" wrote in message
...
jeffies, a boat under sail has one hell of a lot more drag than a
boat
motoring
in a flat calm.

And how is this relevant to anything?



also, keep in mind that the boat under discussion is a Westsail

32, a
boat
usually having a minimum of 30 hp installed, and often 40+ hp.

A Westsail 32 with a 10 to 12 hp engine installed is unmarketable.
One
would
need one hell of a lot patience to wait for wind and tide before
setting
off.

Are you claiming that an aux engine is always run at an rpm that
produces
its
full rated power? Most boaters understand that a diesel might only
produce
half
its rated output at cruise speed. For example, a Yanmar 3YM is

rated
at
29
HP
only delivers about 14 to the prop at 2800 rpm.

Although the OP has a Westsail, he asked what other boaters have
experienced,
so
the discussion is about all boats. As I said elsewhere, I think the
Westsail
would benefit less than other boats from a low drag prop.






keep in mind that props don't drag all that much anyway.
according
to
the
MIT
data, even a fixed 3 blade only pulled 170# on a boat at 5

knots,
or
about
the
equivelent of 2-1/2 hp.


That's not much drag??? That's roughly the drag from a 25 knot
breeze!
Are
you saying that this would have no affect on boat speed?

Are you claiming that a having a 2.5 hp engine pulling backwards
would
have
little affect on speed? At the low RPMs many boats use to go 5
knots,
they
only
use 10 to 12 hp to go forward


















































  #128   Report Post  
Jeff Morris
 
Posts: n/a
Default

Its a little hard to add sail area when you're already at full sail. One major
advantage of lightweight boats is that they can be driven to high speeds with a
relatively small rig. For example, we showed that a Westsail might go 5 knots
with 650 sq. feet of sail in 16 knots of wind. My boat, weighing half that of a
Westsail, will go 8 knots in that wind, with only 540 feet of sail. If I had
3-blade fixed props I'd probably only be doing 7 or even less. The bottom line
is that the folders give me extra speed (or save un-necessary loss) in any
moderate wind condition.



"JAXAshby" wrote in message
...
the drag of fixed props at
low speeds is not that great.


yup.

but that is the market feathering props aim at. at the high end, just a teeny
bit more sail pushes the boat faster than you wanna go anyway.



From: "Jeff Morris"
Date: 9/5/2004 9:55 PM Eastern Daylight Time
Message-id:

Some salesman might have tried to sell you on low speed performance because
he
knew you were scared of high performance boats, but the drag of fixed props
at
low speeds is not that great. Its only really significant at higher speeds.
As
everyone else knows, appendage drag goes up with the square of speed.

Perhaps you can show us even one folding/feathering manufacturer's site that
claims the primary advantage is a low speed.


"JAXAshby" wrote in message
...
btw, jeffies, what everyone else is fully aware of and you are totally

ignorant
of is that folding/feathering prop manufacturers promote their products'

value
at ---- low ---- wind speeds, not high speeds.

duh.


From: "Jeff Morris"

Date: 9/5/2004 3:09 PM Eastern Daylight Time
Message-id:

jaxie, even my cat understands that you changed the thread by claiming the
folders "only have value for racing boats." Now that you've been proven
wrong
on that, you're backpedaling as fast as you can. Don't hurt yourself.



"JAXAshby" wrote in message
...
jeffies, the discussion has from the start been about a Westsail 32.

ask
your
wife to reread the posts for you.

From: "Jeff Morris"

Date: 9/5/2004 10:55 AM Eastern Daylight Time
Message-id:

Time for the meds again, jaxie. Your reading comprehension is failing.
I
made
no claim of the Westsail, I said "At the low RPMs many boats use to go

5
knots,
they only use 10 to 12 hp to go forward." Are you claiming that a
Westsail
is
representative of "many boats"?

If fact, I already said several times that I didn't think a low drag

prop
would
help a Westsail that much, but they could be of value to many other

boats.
You've been claiming that they are useless for any boat other than a

high
performance racer. Since you lost that argument, you're now

backpedaling
and
misrepresenting my comments. Typical lying from cowardly jaxie.

But, since you brought it up, how much power does a Westsail actually

use?
At
5 knots, that is a "Speed to Length" ratio of 0.95 (where the 7 knot

hull
speed
would be 1.34). To achieve that speed, a displacement boat will have

1400
pounds per HP. At 20,000 pounds, the Westsail uses about 14.2 HP. A

bit
higher than the "10 to 12" I mentioned for "many boats," but most 32
footers
don't weigh anywhere near 10 tons. How much wind is needed to

generate
14
hp
on a Westsail? With 650 square feet of sail, assuming 0.02 HP/sq.ft.

at
14
knots wind, this is 13 HP; so it looks like about 15 to 16 knots of

wind
is
needed to get a Westsail up to 5 knots.





"JAXAshby" wrote in message
...
jeffies, **you** claimed it only takes 10 or 12 hp to push a Westsail

32
at
five knots. remember? nah, I am sure you don't remember anything

from
more
than 7 hours ago.

From: "Jeff Morris"

Date: 9/4/2004 11:11 PM Eastern Daylight Time
Message-id:

"JAXAshby" wrote in message
...
jeffies, a boat under sail has one hell of a lot more drag than a
boat
motoring
in a flat calm.

And how is this relevant to anything?



also, keep in mind that the boat under discussion is a Westsail

32, a
boat
usually having a minimum of 30 hp installed, and often 40+ hp.

A Westsail 32 with a 10 to 12 hp engine installed is unmarketable.
One
would
need one hell of a lot patience to wait for wind and tide before
setting
off.

Are you claiming that an aux engine is always run at an rpm that
produces
its
full rated power? Most boaters understand that a diesel might only
produce
half
its rated output at cruise speed. For example, a Yanmar 3YM is

rated
at
29
HP
only delivers about 14 to the prop at 2800 rpm.

Although the OP has a Westsail, he asked what other boaters have
experienced,
so
the discussion is about all boats. As I said elsewhere, I think the
Westsail
would benefit less than other boats from a low drag prop.






keep in mind that props don't drag all that much anyway.
according
to
the
MIT
data, even a fixed 3 blade only pulled 170# on a boat at 5

knots,
or
about
the
equivelent of 2-1/2 hp.


That's not much drag??? That's roughly the drag from a 25 knot
breeze!
Are
you saying that this would have no affect on boat speed?

Are you claiming that a having a 2.5 hp engine pulling backwards
would
have
little affect on speed? At the low RPMs many boats use to go 5
knots,
they
only
use 10 to 12 hp to go forward




















































  #129   Report Post  
JAXAshby
 
Posts: n/a
Default

The bottom line
is that the folders give me extra speed (or save un-necessary loss) in any
moderate wind condition.


keep telling yourself that, jeffies, and pretty soon you will convince yourself
of its "truth". the prop manufacturers don't say that, but you go ahead and
repeat a silly mantra as to how much you "invested".

geesh, don't let science get in your way.


  #130   Report Post  
Jeff Morris
 
Posts: n/a
Default

So are you claiming that the MIT study that said that a 3-blade prop could slow
a boat up to 0.8 knots was bad science? Since I have two props, and frequently
sail at 7 to 9 knots, wouldn't these results be especially important to me?

Sorry jaxie, the science is on my side.




"JAXAshby" wrote in message
...
The bottom line
is that the folders give me extra speed (or save un-necessary loss) in any
moderate wind condition.


keep telling yourself that, jeffies, and pretty soon you will convince

yourself
of its "truth". the prop manufacturers don't say that, but you go ahead and
repeat a silly mantra as to how much you "invested".

geesh, don't let science get in your way.




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