On 04 Sep 2004 23:25:53 GMT,
Shen44 wrote:
ubject: What are the pros and cons of a folding prop?
From: "Jeff Morris"

If you insist on calling the Autoprop "feathering" then you have to admit its
a
pretty poor one, having 5 to 10 times the drag of other feathering props.
For
example, in the MIT/Practical Sailor test, at about 7 knots the Autoprop had
10
pounds of drag, while the 2 and 3 blade Maxprop feathering props had about 1
and
2 pounds respectively. The folding props were so low they weren't shown. 10
pounds of drag is pretty good, compared to the 25 to 35 pounds for many of
the
props in the test, but it isn't the same as feathering. The Autoprop has
some
interesting properties, like very good performance in reverse, if you rev

From this, and looking at diagrams of both the "maxprop" and "autoprop", it
appears that both designs can rightly call themselves "feathering".
However, it appears that the design of the hub of the autoprop is such that it
still creates a marked amount of drag which has little to do with the
shape/curvature of the blades.
Agree/disagree/comments?

Shen


Sounds about right to me, the autprop looks like it would produce
significantly more drag than the Max prop to me, and that both, would
produce less drag than a fixed. Since I think the autoprop is about the
same $$ as the Max prop, I'd go for the Max, unless there was some real
good reason otherwise. Maintenance maybe? is the Max prop a lot more
work to maintain?

--
Jim Richardson http://www.eskimo.com/~warlock
"`If there's anything more important than my ego around, I
want it caught and shot now.'"
-- Zaphod

jim, if you had your mind made up that you were going to spend two and half big
boat bux to buy a tiny increase in performance at some considerable increase in
maintenance, why in hell did you ask for people's opinions? It just made you
look stew ped. Which you have a right to do, of course. But why announce it
to the world?

From: Jim Richardson
Date: 9/4/2004 8:00 PM Eastern Daylight Time
Message-id:

On 04 Sep 2004 23:25:53 GMT,
Shen44 wrote:
ubject: What are the pros and cons of a folding prop?
From: "Jeff Morris"

If you insist on calling the Autoprop "feathering" then you have to admit
its
a
pretty poor one, having 5 to 10 times the drag of other feathering props.
For
example, in the MIT/Practical Sailor test, at about 7 knots the Autoprop
had
10
pounds of drag, while the 2 and 3 blade Maxprop feathering props had about
1
and
2 pounds respectively. The folding props were so low they weren't shown.
10
pounds of drag is pretty good, compared to the 25 to 35 pounds for many of
the
props in the test, but it isn't the same as feathering. The Autoprop has
some
interesting properties, like very good performance in reverse, if you rev

From this, and looking at diagrams of both the "maxprop" and "autoprop", it
appears that both designs can rightly call themselves "feathering".
However, it appears that the design of the hub of the autoprop is such that
it
still creates a marked amount of drag which has little to do with the
shape/curvature of the blades.
Agree/disagree/comments?

Shen


Sounds about right to me, the autprop looks like it would produce
significantly more drag than the Max prop to me, and that both, would
produce less drag than a fixed. Since I think the autoprop is about the
same $$ as the Max prop, I'd go for the Max, unless there was some real
good reason otherwise. Maintenance maybe? is the Max prop a lot more
work to maintain?

--
Jim Richardson http://www.eskimo.com/~warlock
"`If there's anything more important than my ego around, I
want it caught and shot now.'"
-- Zaphod