Today's Message Index:
----------------------
1. 05:26 AM - Tubes are straight now (John Bickham)
2. 06:54 AM - Warp Drive prop question (John Cooley)
3. 07:15 AM - Re: Warp Drive prop question (John Hauck)
4. 08:34 AM - Re: Prop noise (John Jung)
5. 08:54 AM - Re: Warp Drive prop question (J.D. Stewart)
6. 09:11 AM - Re: Prop noise (John Hauck)
7. 10:06 AM - Re: Prop noise (Richard & Martha Neilsen)
8. 10:08 AM - Re: Warp Drive prop question (Kirk Smith)
9. 11:30 AM - Re: Warp Drive prop question (Richard Pike)
10. 01:42 PM - Just A Few More Days Left; Lagging Behind Last Year... (Matt Dralle)
11. 03:38 PM - MKlllx Speed (Cat36Fly@aol.com)
12. 07:04 PM - Static Run (ElleryWeld@aol.com)
Message 1
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| Subject: | Tubes are straight now |
--> Kolb-List message posted by: "John Bickham" <gearbender@bellsouth.net>
Hello list,
After input and responses to my questions on how to straighten bent tubes, I
was pretty successful yesterday. That is the great thing about this list.
You can get a lot of good ideas from individuals and even combine them and
come up with great solution. Made it real simple to do.
Thanks Jimmy H, Bob B, Woody, & the rest for the responses.
It kinda surprised me how far past straight you have to bend the tubing to
get a good result. My first attempt didn't allow for this.
Drilled a 4 x 4 down the center and split it with a band saw.
Used a Harbor Freight (cheapo) Porta Power and some scrap metal fence
material to make a press. I used pre-punched 1.5" channel. Welded a little
extra gusset on 1//2" square bar to make sure the tubing was the first part
to bend.
My first attempt wasn't long enough or deep enough to allow for the flex.
Pictures are worth a thousand words. Check out the web page if you are
interested.
http:/home.bellsouth.net/p/pwp-8jb
<file:///C:\Documents%20and%20Settings\Big%20Daddy\My%20Documents\8JulietBra
vo%20Web%20Page>
Do Not Archive
Thanks again,
John Bickham
St. Francisville, LA
Message 2
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| Subject: | Warp Drive prop question |
--> Kolb-List message posted by: "John Cooley" <johnc@datasync.com>
Hi Guys,
Got a question for you Warp Drive folks or anyone that can enlighten me. I
bought a 66" 2 blade taper tip prop for my MK II that I have been sprucing
up to sale. I didn't like the GSC prop that was on it is the reason for
switching. Anyhow back to the question. With the GSC and the Powerfin prop
on my FS II I would always set the prop for about 6200~6300 static rpm's to
achieve the 6600~6700 level flight WOT rpm's. The prop unloads in flight and
turns higher rpm's, right?
Well, with this prop I first set it up turning 6200 rpm's on the ground and
took it up for a test flight. Max level flight rpm's was about 5700~5800
rpm's and the engine was real slow to rev up. This scared me for a minute or
two as I thought something was going wrong with the engine.
I then went back and adjusted the prop twice more and wound up with 6600
static and 6400 WOT level flight.
This prop came off a Firestar and supposedly vibrated real bad and this was
the reason for selling. I fixed the vibration problem, but am puzzled by the
lower rpm's in WOT level flight. The climb rate seems about normal but I
really couldn't tell as it was very bumpy yesterday. My butt came out of the
seat a few times while descending for landings.
I have heard of constant speed blades on Warp drive props. Is this possibly
the reason for the lower flight rpm's I am seeing?
Thanks,
John Cooley
--
Message 3
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| Subject: | Re: Warp Drive prop question |
--> Kolb-List message posted by: "John Hauck" <jhauck@elmore.rr.com>
possibly
| the reason for the lower flight rpm's I am seeing?
|
| Thanks,
| John Cooley
John C/Gang:
Yep.
Set pitch so it will bump the red line at WOT straight and level
flight. You will then obtain the best cruise and climb. That's the
way it works, and that is the way the two strokes, especially, like to
be set up. 5,800 rpm is about 75% power. I ran my two strokes,
primarily, at this rpm and had very good luck with them. I run the
912/912S at 75% power and higher.
My 3 blade taper tip Warp Drive is pitched for 5,400 rpm static. A
few feet into take off roll, the rpm drops 100 to 150 rpm and stays
that way throughout WOT climbs. WOT, straight and level is 5,500.
john h
MKIII/912ULS
Message 4
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--> Kolb-List message posted by: John Jung <jrjungjr@yahoo.com>
Ed and Group,
I raised the engine by using longer bolts and washers and nuts for
spacers. I measured it since my last post and it was closer to 1/2 inch
that I had raised it. But the sound difference was noticeable. The
bolts are long enough to go up 3/4 inch, so I will try that.
John Jung
Firestar II N6163J
Surprise, AZ
On Nov 27, 2005, at 12:56 AM, Kolb-List Digest Server wrote:
> John,
>
> I dont have any advice, But I would like to know how you raised
> your
> engine that 1" and how noticeable of an effect it had on flight
> characteristics.
>
> Ed ( In Houston)
Message 5
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| Subject: | Warp Drive prop question |
--> Kolb-List message posted by: "J.D. Stewart" <jstewart@inebraska.com>
It's amazing how the same subject comes up about the same time on different
lists. I've seen this time and time again. Here's an exchange from the
Titan list (pretty long, but worth the read) during the last few days
concerning this very thing:
-----Original Message-----
From: Titanaircraft@yahoogroups.com
[mailto:Titanaircraft@yahoogroups.com]On Behalf Of Kimberly Panos
Subject: Re: [Titanaircraft] tapered prop
Thom,
By eliminating prop area (wing area), it reduces the amount of total thrust
(lift if a wing) the prop is capable of at a given RPM (speed). As a
conventional piston engine's RPM increases, horsepower increases in a
relatively linear fashion (to a point), but the load imposed on the engine
by the prop increases by the square. This means that when the prop load
matches the available horsepower, the engine RPM can't increase (kind of
like hitting a wall). The tip is where the most lift and drag can be
created. After a conventional piston engine reaches it's peak design torque
RPM(determined by bore/stroke combination, cam, compression, heads,
induction system, manifolds, etc.), the torque begins to fall while the prop
load increases.
How and where you reduce the area is crutial. For example, if you had an
unlimited controllable power source that you could turn both props to 3000
RPM, the straight blade, non-tapered tip would produce more thrust and
require more power, even though the tip speed is the same. It kind'a boils
down to physics. You don't get anything for free. By tapering the tips,
the taper tip prop isn't capable of producing the same thrust at the same
RPM as before, but allows the engine to get to its peak operating range
which would allow the maximum thrust that the engine/prop combo is capable
of while maintaining the prop speed (tip speed). It's much more efficient
than running a short, stubby prop or stubby props with many blades. That's
another reason two blades provide better performance than three for the same
application. It allows a larger diameter and more pitch for the same load.
If they weren't any more noisy on a pusher, you can bet we'd be running
two-blade props instead of three-blade (as long as they clear the tailboom).
I'm sorry can't think of a real simple explanation for that one. I think
I'd better quit here since the more I elaborate, the more complicated it's
getting.
cheers,
--Kimberly
----- Original Message -----
From: "Thom Riddle" <jtriddle@adelphia.net>
Subject: [Titanaircraft] tapered prop
> Kimberly,
>
> Thanks for the explanation and it sounds plausible but confusing a bit, at
> least to me, for
> two reasons.
> 1) How does the Warp Drive prop NOT change rpm much from relatively low
> speed Vy
> climb under full throttle, to straight and level full throttle speeds at
> least 30-40 mph
> faster, without a flexing or pitch change?
> 2) My Woodcomp prop is gradually tapered along the chord from about 25-30%
> radius out
> to about 95%, then sharply tapered the last 5% or so. If it the tapering
> that enables this
> strange phenomenon and not flexing lateraly (effectively changing pitch
> dynamically), then
> my Woodcomp should show similar rpm behavior, wouldn't it?
>
> I'm not questioning you explanation just trying to understand why the Warp
> does what it
> does and others that look similar do not. The leads me to believe that
> their is some
> dynamic lateral flexing (pitch changing) in the Warp that is not happening
> in the
> Woodcomp and others. It does not take much pitch change to make a big
> difference in
> rpm.
>
> Thom
> --- In Titanaircraft@yahoogroups.com, "Kimberly Panos" <krpanos@n...>
> wrote:
>>
>> Thom,
>>
>> The so-called CS effect of a warp really isn't because the blades warp.
>> I
>> haven't seen the tips warp or flex on ours at all, even on near full
>> throttle runups. What it does is provide less load at the tip (where the
>> load is hardest to turn) to allow the engine to get up to it's peak
>> horsepower, but keep the prop tip speed alive while doing so. This keeps
>> the efficiency up and the load down. Just like a glider wing compared to
>> the wing on the Tornado. While the two could have the same square
>> footage,
>> the glider wing (due mainly to its high aspect ratio wing), it is much
>> more
>> efficient (more lift, less drag), but not as stout enough to carry heavy
>> loads. Notice that the majority of all certified modern aircraft (except
>> a
>> few like the Archer, trainers, etc) use a tapered chord wing, as does the
>> propeller on mainly piston prop planes because they are more efficient
>> and
>> not because they twist or warp. A constant chord wing is just cheaper
>> and
>> easier to produce, provides docile characteristics, and keeps speeds down
>> for some aircraft categories. The main reason why you'll see those
>> mostly
>> on metal-winged kit planes and trainers.
>>
>> The nice thing about being able to taper a finished prop is to customize
>> the
>> prop load while keeping efficiency up, unlike most other composite props
>> where you can only chop them off for length -- a dismal experience we had
>> with Ivo where the medium HP blades were just down-right too wide for the
>> high RPM requirement of the Jabiru.
>>
>> --Kimberly
And one of the first posts on the subject:
From: "Barry Weinzirl" <rans9@wwt.net>
Subject: Re: [Titanaircraft] Re: Propwash, Texas to Santa Ynez, CA: The Very
Long Story
If you run a warp drive taper tip you will usually static more rpm then what
you turn as you get rolling. I have the same thing on my 503. I will static
a 100rpm or more than what I turn in the climb. It has to do with parts of
the prop being stalled until you get some forward air moving through it. At
least that is what warp says. And they only gain a few hudred between climb
and strainght and level. They are very tight. Barry
There you go. Hope that helps.
Warp Drive Dealer,
J.D. Stewart
UltraFun AirSports, LLC
www.ultrafunairsports.com
Titan Aircraft E-mail list
http://groups.yahoo.com/group/Titanaircraft/
Challenger E-mail list
http://groups.yahoo.com/group/FlyChallenger/
> Kolb-List message posted by: "John Cooley" <johnc@datasync.com>
>
> Hi Guys,
> Got a question for you Warp Drive folks or anyone that can enlighten me. I
> bought a 66" 2 blade taper tip prop for my MK II that I have been sprucing
> up to sale. I didn't like the GSC prop that was on it is the reason for
> switching. Anyhow back to the question. With the GSC and the Powerfin prop
> on my FS II I would always set the prop for about 6200~6300
> static rpm's to
> achieve the 6600~6700 level flight WOT rpm's. The prop unloads in
> flight and
> turns higher rpm's, right?
> Well, with this prop I first set it up turning 6200 rpm's on the
> ground and
> took it up for a test flight. Max level flight rpm's was about 5700~5800
> rpm's and the engine was real slow to rev up. This scared me for
> a minute or
> two as I thought something was going wrong with the engine.
> I then went back and adjusted the prop twice more and wound up with 6600
> static and 6400 WOT level flight.
> This prop came off a Firestar and supposedly vibrated real bad
> and this was
> the reason for selling. I fixed the vibration problem, but am
> puzzled by the
> lower rpm's in WOT level flight. The climb rate seems about normal but I
> really couldn't tell as it was very bumpy yesterday. My butt came
> out of the
> seat a few times while descending for landings.
> I have heard of constant speed blades on Warp drive props. Is
> this possibly
> the reason for the lower flight rpm's I am seeing?
>
> Thanks,
> John Cooley
>
Message 6
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--> Kolb-List message posted by: "John Hauck" <jhauck@elmore.rr.com>
| bolts are long enough to go up 3/4 inch, so I will try that.
|
| John Jung
John J/Gang:
Let me ask you a question.
In the process of raising the thrust line to reduce noise, are we also
reducing performance?
john h
MKIII
Titus, Alabama
Message 7
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--> Kolb-List message posted by: "Richard & Martha Neilsen" <NeilsenRM05@comcast.net>
John/All
You would think that raising the trust line would decrease performance but I
don't see it. I had 7 inches of clearance between the boom tube and the tips
of my 72 inch prop with my old engine mount. Now with the lower engine mount
I have app 1.75 inch clearance. This is likely much more than most people
would move their thrust line but I had no detectable change in performance.
With that said I did have some very undesirable handling issues with the
high thrust line but again most people will not likely move their thrust
line up as high as I did. In my own defense I didn't just create that high
thrust line for the heck of it. The VW engine with the Valley reduction
drive just didn't allow a lower mounting with the stock Kolb cage/engine
mount.
Rick Neilsen
Redrive VW powered MKIIIc
----- Original Message -----
From: "John Hauck" <jhauck@elmore.rr.com>
Subject: Re: Kolb-List: Prop noise
> --> Kolb-List message posted by: "John Hauck" <jhauck@elmore.rr.com>
>
>
>
> John J/Gang:
>
> Let me ask you a question.
>
> In the process of raising the thrust line to reduce noise, are we also
> reducing performance?
>
> john h
> MKIII
> Titus, Alabama
Message 8
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| Subject: | Re: Warp Drive prop question |
--> Kolb-List message posted by: "Kirk Smith" <snuffy@usol.com>
. The prop unloads in flight and
> turns higher rpm's, right?
> Well, with this prop I first set it up turning 6200 rpm's on the ground
and
> took it up for a test flight. Max level flight rpm's was about 5700~5800
> rpm's
In this case it appears that the prop loads up in flight. Probably the
forward motion of the craft through the air is providing more air molecules
for the prop to displace. At least less turbulent air.
Do not archive
Message 9
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| Subject: | Re: Warp Drive prop question |
--> Kolb-List message posted by: Richard Pike <richard@bcchapel.org>
What engine/gearbox combination do you have that prop on? Years ago I had
an Anglin J-6 with a 503 on it and a 66" Warp Drive 2 blade, and I had
exactly the same situation. I had to prop it for a high static rpm because
as I began my takeoff roll, the prop would load up and the RPM's would
decrease. It acted exactly as if the prop were stalled at static rpm, and
was revved a bit higher than you would expect - and then unstalled and
loaded up and slowed down as the takeoff roll began - which actually makes
sense, because a 2 blade prop will have a higher angle of attack (more
pitch) than a three blade prop for a given horsepower and prop diameter,
and might have had too much pitch for realistic results at a static runup.
But as soon as forward speed increases at takeoff, the blade unstalls and
loads up the prop, and the engine slows down.
I have my MKIII/582 propped for about 64-6500 WOT, so it sounds like you
are currently in the ball park, even though you got there by non standard
means.
Richard Pike
MKIII N420P (420ldPoops)
At 08:54 AM 11/27/2005 -0600, you wrote:
>--> Kolb-List message posted by: "John Cooley" <johnc@datasync.com>
>
>Hi Guys,
>Got a question for you Warp Drive folks or anyone that can enlighten me. I
>bought a 66" 2 blade taper tip prop for my MK II that I have been sprucing
>up to sale. I didn't like the GSC prop that was on it is the reason for
>switching. Anyhow back to the question. With the GSC and the Powerfin prop
>on my FS II I would always set the prop for about 6200~6300 static rpm's to
>achieve the 6600~6700 level flight WOT rpm's. The prop unloads in flight and
>turns higher rpm's, right?
>Well, with this prop I first set it up turning 6200 rpm's on the ground and
>took it up for a test flight. Max level flight rpm's was about 5700~5800
>rpm's and the engine was real slow to rev up. This scared me for a minute or
>two as I thought something was going wrong with the engine.
>I then went back and adjusted the prop twice more and wound up with 6600
>static and 6400 WOT level flight.
>This prop came off a Firestar and supposedly vibrated real bad and this was
>the reason for selling. I fixed the vibration problem, but am puzzled by the
>lower rpm's in WOT level flight. The climb rate seems about normal but I
>really couldn't tell as it was very bumpy yesterday. My butt came out of the
>seat a few times while descending for landings.
>I have heard of constant speed blades on Warp drive props. Is this possibly
>the reason for the lower flight rpm's I am seeing?
>
>Thanks,
>John Cooley
>
>
>--
>
>
Message 10
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| Subject: | Just A Few More Days Left; Lagging Behind Last Year... |
--> Kolb-List message posted by: Matt Dralle <dralle@matronics.com>
Dear Listers,
There are just four more days left of this year's List Fund Raiser! Response has
been very good, but we are behind last year as far as the number of people
that have made a Contribution and as a percentage of the total number of subscribers.
Please remember that there isn't any sort of commercial advertising on the Lists
and the *only* means I have of keeping these Lists running through your Contributions
during this Fund Raiser.
Please make a Contribution today!
http://www.matronics.com/contribution
Thank you!
Matt Dralle
Matronics Email List Administrator
Matt G Dralle | Matronics | PO Box 347 | Livermore | CA | 94551
925-606-1001 V | 925-606-6281 F | dralle@matronics.com Email
http://www.matronics.com/ WWW | Featuring Products For Aircraft
do not archive
Message 11
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--> Kolb-List message posted by: Cat36Fly@aol.com
For those that are interested I made some speed runs today as conditions
were decent. It got to about 45-50 degrees today and I was able to consistently
get 1000 FPM climb on repeated take offs. That was with 6500 RPM and 58-60 MPH
indicated.
I made a couple of runs where I kept inching up the throttle and arrived at
84 MPH indicated turning 6500 RPM. I'm finding 5000 RPM is a comfortable
cruise setting and seems to be somewhat fuel efficient.
Read a couple of posts concerning the loading/unloading of props. I'm
turning a 66" Warp 3 Blade With taper and do not see any difference at WOT on
the
ground or in the air (6500 RPM). However, I will watch closer from now on.
Larry Tasker
MKlllx 582 3-blade warp
Message 12
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--> Kolb-List message posted by: ElleryWeld@aol.com
That's kinda not what I have seen at all in my testing & setting prop pitch,
I static run my prop to 6000 Rpms on the ground tied to my truck @ WOT. and in
flight I get 6250 rpms right where I want it at WOT so I don't over rev my
engine and kill the life of it sooner than expected, 300 HR Rebuilds come to
soon anyway but also I cruse at 5500 RPM IAS at 65 mph
Or am I doing something wrong?
Original Firestar I am putting the skis on it this week are You?
Ellery Batchelder Jr.
do not archive
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