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F3A Results - SPOILER

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Old 08-04-2012, 04:28 AM
  #51
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Could it be that the ability to pick-up an unknown, fly it, and fly it well in a contest, whatever the prevailing conditions, has more to do with winning at the top than glow vs electric? And if so, what does that say for how we practice pattern while rising up through the classes (the vast majority of us are somewhere in the middle and few if any will make it to the top for obvious reasons). The interesting thing is - aside from the amount of time devoted to practice (daily, weekly, whatever) - that we tend to fly the schedule we are working on and the only unknowns are those that come from missing a maneuver and recovering from the resulting attitude LOL!  I mean, perhaps we need to find a way to practice something "unknown" on the way up as that seems to be an ability, skill, unto itself (even though it is not needed to fly the AMA classes). Anyone doing this? Thoughts? Cheers!
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Old 08-04-2012, 07:24 AM
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Quote:
ORIGINAL: serious power

Hi Brett,
You may be giving the judges credit based on your own belief system.
I would advise you to be careful with that.
In truth they do their job at a fairly basic level ,for the most part.

To win you need a very very high level of technical perfection and add to that a 'style factor'.
If you get the style factor right the judges may be a little more tolerant of technical errors.
I must emphasise the 'little' in a little more tolerant.
Both are absolutely required to win

The YS on glow is a pleasant sound ,no more than that (I loved it myself), the CDI is just like any other Honda 50.
It is just another single cylinder 4 stroke engine.

The geared inrunners do have a high pitched 'whine'.

However the Neu has as much low end torque as any YS and it wont bog down if you get it a little too low down so there is never any lag. Electrics self govern to some extent.

Brenner's contra when powered by the Neu takes low end torque to a whole new level.
This aspect is what really strikes people when they see it for the first time.

As for the reduced work-load aspect.
With the contra , 'spiral slip stream' aside, P-factor is gone as is almost all the precession and 90% of the motor torque that would normally go into the airframe.

Again 'perception is reality'.

Brian

PS; So far Mayr has used the electric only at the EC's, that's after using the YS at multiple World cup events, for the slower speed capability apparently.
Anyone who has taken a few minutes to analyze a few tear sheets at the worlds can tell you that judging isn't always as straight forward as we want it to be. When you want to be the best, you have to make an impression. Obviously, technical accuracy trumps all, but past that impression makes a difference.

I cannot speak for the low end torque of a Neu, only the fact that every single one I've seen fly has flown significantly farther out and faster than me.

As for the contra... there was one guy running it in the finals at the US Nats, it's country of origin, and now he's switching to glow. Chip's Visa was heavier than our YS powered Alferma. If you looked at the two airplanes side by side you may find that pretty hard to believe (but it's true). The contra seems to be fixing a problem that doesn't really exist and creating 5 more. Again, no personal experience, just observation.
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Old 08-04-2012, 08:09 AM
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Hi Brett,
I have flown them all, 2st, 4st, outrunner/pletty and the Neu/Contra - sometimes equally badly.
I can speak to the low end torque of each.
I also fly a large bipe.
The conversation I'm having is about 'the mass migration back to glow'.
If this is to fix the 'low end torque' problem it truly will be in vein as this is a problem that does not exist.
There are plenty of 'E' options that deliver low end end torque. Some of these deliver high end speed as well.
You should try the Neu and or the contra, if only so as to have the experience.

Perhaps you could run through the problems you observe with the contra.
I would find that helpful and I'm sure Brenner would also.

Brian
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Old 08-04-2012, 08:38 AM
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Hi Brian

I would say your flying a small bipeand if you have not competed with the 175, you, can`t compare!

Brett may be a little coy sometimes But, he is a convert from electric to glow. He knows the ends and outs of both systems.
I have flown contra setups, I do believe they have merrit! but there is no comparison in tourque( precise ,usable tourque) to a 1.75 nor the flexibility on prop selection, especially at the end of the flight!
I`m not saying the contra is Bad by all means, I`m designing a airplane for one But apples to apples they don`t match up to current glow flexibility. Both Systems have made and continue to make strides to improve and I commend Brenner for his Work, as well as Yamada!

You assume Brett`s a Rookie? LOL A 12`th and 13`th place in the World Champs gives him some creds I think, to understand the human nature of scoring and the ability to select a airplane setup to get there
The ability to pull that last fraction of a score ,is what seperates the top pilots. pulling that last bit of number by either , impression, or technical Skill.

We were Quiet when the Electric guys were having their hayday! pronouncing" the end of glow! and " dogging the "SLIMERS" But now it seems like the new Success of YS to pull back to the top, may have offended guys who made the switch LOL. (Im not aiming this at anyone in particular)

It kinda is a Chevy Verses Ford Argument for armchair pilots ,but not to the Guys burning the Fuel [X(] and in the trenches. as new schedules change so does the systems to make the podium. it`s why you will see 50% bipes in the finals at the worlds in years to come.

Bryan

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Old 08-04-2012, 08:56 AM
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Hi Bryan,
I know Brett's track record reasonably well, and it is impressive. I just suggest he try a contra.
I agree 100% with your last paragraph .
I do not agree at all with your joint position on torque and flexibility.
In fact I would contend the opposite.
Just take braking as an example.

One of the great mass migrations on the planet is that of the wilder-beast .
They wander all over the place in search of food and water.
The biggest crocodiles on the planet just wait in the watering holes

Brian
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Old 08-04-2012, 09:02 AM
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Default RE: F3A Results - SPOILER

I watch Andrew fly a few times each month- and pay attention to motor setups - power used etc..
Guy has been puttering with his new FAI plane - Darin also has been working at his - electric - My 20 year Dalotel - also now electric and better than it ever was on glo
There are different thoughts on batteries - weight vs C rating
The setup Andrew used - a outrunner and a light model ,sure looks like the future to me
My guess is lighter yet with more power from better cells ( higher C) Motor Power is NOT an issue-
IC engines - If you like em but doing away with the vibes and attendant wear n tear plus iffy sound tests leads me to believe they require more effort than many will consider for future use..
Every one has an opinion -
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Old 08-04-2012, 09:14 AM
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Default RE: F3A Results - SPOILER

Hey Brain,


The inherent problem right now is airframes available that will accept a YS,..as you well know (that don't cost an arm and a leg to get). I am still using to VF3's one EP and one YS that I just converted. However, in saying that I made sure I could convert it back, if necessary. I know how much better I fly with the YS and I struggle a bit with the EP. In all honesty, I didn't get to fly the EP as much as I wanted, before I put them up to play in the sandbox. I flew my YS even less about mid-season, giving the EP a go and experimenting.

I like the flight characteristics of both and somewhere in the mix is the happy medium we all search for (preference). I stay pretty neutral on the subject. I see guys convert to EP and do very well and Guys like Brett that went the other way and do very well. I think the Worlds will be a tell-tell as to whats to come?

anyway,..wanted to share that,..good luck with the design work!

bholsten
Dist2 F3A/FAI Champion 2009.


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Old 08-04-2012, 09:35 AM
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LOL

Brian,
It`s good we agree on most things I know we are after the same goals.

But I say this, the goal in a good current set up in my opinion is this.
The more breaking and lift you can get from the airframe ,the less you rely on the breaking from the prop. Now,The more ability you have to select the best overall prop. because you dont need the low pitch for breaking,, Higher pitch,-quieter prop.
Multy blades have never and will never trump single blades in flexibility and efficiency.Drag for the most part should only be the result of,or byproduct of lift (as much as you can afford) and running 13-14 inch picth on any motor cannot give you both good breaking, and low end touque even with multy blades. (APPLES TO APPLES)

This is why the Bipe is the best setup, but till now , we have not had the power or the abilty to take advantage of this goal.
Thin wing bipes are just as fast or faster than the mono planes (using the speed to achieve lift) ,it`s why you saw QQ use a four blade (for breaking) and when he flew the electric version he flew even faster!
The new Bigger Bipes have the breaking built in the airframes,not the props.


As far as the sound test, there were many electric that were right on the edge , one glow, us,one Contra, Chip , failed, till they recalibrated the meter.
There is some wear and tear to be sure with glow, but as always, the better the build,setup ,the better the longevity of equipment.
Plus We were queter than almost all the electrics in the air.

I dare say unless you fly masters or FAI for the most part you never fly more than 200 flights a season anyway and if you make a season on one set of equipmet (servo`s ect ) thats really very good.
Bryan
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Old 08-04-2012, 09:36 AM
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Hey Bill I undestand

I`m working on that problem as we speak
Bryan
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Old 08-04-2012, 10:31 AM
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Default RE: F3A Results - SPOILER

Gonna have to come up with another word other than "Glow" now that you have a spark plug in your YS
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Old 08-04-2012, 10:52 AM
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Use what the heli guys do, electric and nitro.
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Old 08-04-2012, 01:56 PM
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Ahh,..Kool,..Sorry spelled your name wrong again Bryan. Looking forward to it,..

My Bad,.........[8D]



Bholsten
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Old 08-05-2012, 11:49 AM
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Quote:
ORIGINAL: flyncajun

LOL

Brian,
It`s good we agree on most things I know we are after the same goals.

But I say this, the goal in a good current set up in my opinion is this.
The more breaking and lift you can get from the airframe ,the less you rely on the breaking from the prop. Now,The more ability you have to select the best overall prop. because you dont need the low pitch for breaking,, Higher pitch,-quieter prop.
Multy blades have never and will never trump single blades in flexibility and efficiency.Drag for the most part should only be the result of,or byproduct of lift (as much as you can afford) and running 13-14 inch picth on any motor cannot give you both good breaking, and low end touque even with multy blades. (APPLES TO APPLES)

This is why the Bipe is the best setup, but till now , we have not had the power or the abilty to take advantage of this goal.
Thin wing bipes are just as fast or faster than the mono planes (using the speed to achieve lift) ,it`s why you saw QQ use a four blade (for breaking) and when he flew the electric version he flew even faster!
The new Bigger Bipes have the breaking built in the airframes,not the props.


As far as the sound test, there were many electric that were right on the edge , one glow, us,one Contra, Chip , failed, till they recalibrated the meter.
There is some wear and tear to be sure with glow, but as always, the better the build,setup ,the better the longevity of equipment.
Plus We were queter than almost all the electrics in the air.

I dare say unless you fly masters or FAI for the most part you never fly more than 200 flights a season anyway and if you make a season on one set of equipmet (servo`s ect ) thats really very good.
Bryan
Bryan, I find your argument kind of incongruent. You say "Drag for the most part should only be the result of,or byproduct of lift" and then you say "The new Bigger Bipes have the breaking built in the airframes,not the props". Sounds like you are increasing drag to control downline speed not lift. You say "the less you rely on the breaking from the prop. Now,The more ability you have to select the best overall prop. because you dont need the low pitch for breaking". It would seem to me that the fact you can control the braking on the electric trumps the fixed braking of the YS and allows more flexibility in the airframe design as you don't need to add drag. And by the way the Contras use very high pitch props. And by the way electrics have very high low end torque. And I'll have to check but I believe prop drag is affected more by the diameter than the pitch.

You might be right that the YS/bipe is the best setup but I don't think you have the best argument for it.

Respectfully, Jim O
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Old 08-05-2012, 01:50 PM
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Default RE: F3A Results - SPOILER

There is a VERY BIG difference between biulding drag into the airplane, is just that the new bipes are designed to FLY SLOW, without parasit drag, just using induced drag, and in the air it makes a very big difference to take a down line with a slow bipe Vs the same down line with an airplane that uses prop braking

trust me! you have to fly it to believe it! in my opinion a YS powered bipe is the way to go
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Old 08-05-2012, 02:54 PM
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Default RE: F3A Results - SPOILER

Just an observation from the peanut gallery, but in the Unknown #2 round (the only FAI I saw at the Nats) JAS appeared to have excellent control in all regimes with his e-bipe.

This is all very subjective and only you Top Dogs in FAI and Masters can appreciate the finer points, but to my minimally trained eyes it seemed, if anything, that the e-bipe struggled a bit less in the looping KE parts in very windy conditions.

In any event, a couple of us judged from that one round the final outcome - AJ, JAS, Brett and Chip - based purely on the flying. Damn, these guys are good!
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Old 08-05-2012, 03:23 PM
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Default RE: F3A Results - SPOILER

Thanks to Jim Oddino to bringing some actual correct physics to this discussion. For most of this I am again reminded of my old coach Harry Roe and his "aerodramatics" term.

It would also be nice if those that are stating that their set-up is the ultimate game changer did it from a position of strength in their placing in the contest instead of telling us all, just trust us. Not that placing third and making the team is not a fantastic accomplishment, it certainly is. And I applaud Brett and Bryan for making it. But it comes across a little weak when 1st and 2nd were electric and so dominated the final scores. And I also think it cheapens Brett's incredible accomplishment as the most important part of the equation, the pilot.
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Old 08-05-2012, 03:29 PM
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Jim,

You are looking at specific details and missing the big picture. The increased drag is what keeps the downlines slow, yes, so we can maintain constant speed while keeping the airplane in close and slow. This trend towards more drag has been popular for many years now... it's one of the reasons cited for fixed landing gear. What Bryan is saying is that instead of adding things to the airplane that create parasitic drag to achieve the total drag we need for slow downlines, instead lets use induced drag so that we are killing two birds with one stone. Parasitic drag helps in one area: downlines. Because it is specifically added for this one area and attitude of flight, it is inefficient in its purpose. Engineering is all about simplicity. How can we make the least amount of factors do the most amount of work for us? By creating more lift we are solving the problem of airplane stability at low airspeeds (also solving many other problems, but that's outside the scope here) but also creating the total drag (more of which is induced) needed for our constant speed downlines. Now that we have the drag we need as a factor of the lift we have created we can get rid of all that stuff hanging off the airplane (bye bye fixed gear!).

Now, as for the props, these are actually what we've been using to create this parasitic drag. Relying on the prop for our drag significantly reduces the options we have for propellers... questions like: how hard is it for the motor to turn this propeller? how hard is it to make sound with this prop? how hard much does this prop weigh? all become increasingly insignificant in the face of "how slow are my downlines with this propeller?"

OK, so, why not just run electric, set the ESC to brake a certain amount, and be done with it? This is where the "low end torque" I talked about comes into play. Perhaps, technically, an electric has low end torque, but we do not always have the advantages of extensive research and scientifically proven numbers, graphs, etc. in our hobby because we are a small blip in the world. The lack opportunity for real money in our sport means most of our information is empirical in nature so in explaining certain views or concepts assumptions can be made based on observation that may not be technically accurate. In any case, what I mean to say is that to fly slow with a 2-blade propeller electric you essentially have one choice: a 22x12. Why? because with a 20x14, or 20x15 (I'm sure there are other sizes out there, I'm just remembering props I used to run when I flew electric) there is no resolution on the bottom half of the stick. Perhaps this is actually because of the high pitch of the propeller and not the motor itself, I'm not entirely sure, but I know it's real because I've experienced it. On the other hand, with my YS powered Euphoria (which is actually a very slippery airframe), I can run a 19.5x11.5 and still have the resolution and authority at the bottom portion of the stick to fly slow but the sheer power and speed to fly into a strong headwind. With an electric, I can't have both of those. The 20x15 gives me the speed I need but not the slow flight. The 22x12 gives me the slow flight, but not the speed (and also destroys my batteries). The contra seems to be better in this regard but by it's nature it limits our airframe flexiblity. We need big batteries to get through a big unknown with a contra, but when we're running a big battery and a heavy contra unit now we don't have any options but to fly a small, light airframe.

YS is the best of all of these worlds. However, they take extra effort to operate and compete with and that trumps everything else for some. Electrics are popular for one reason far and above the rest: convenience. Convenience, for someone who strives for perfection, is a very trivial thing.

P.S. In response to Tony's post, because he replied as I was writing my response above: Andrew and Jason outflew me, no question. Let's consider something else, though. I arrived at the Nats with 15 flights on the Alferma. Also, my first season as a pattern pilot (in intermediate) was 2005. That's the same year Jason was in France for the World Championships and just 2 years before Andrew made his first team. I also don't fly in any other competitions aside from pattern. I don't believe I would have been 3rd with 15 flights on Andrew's or Jason's airplane.
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Old 08-05-2012, 03:36 PM
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Quote:
ORIGINAL: tuny

There is a VERY BIG difference between biulding drag into the airplane, is just that the new bipes are designed to FLY SLOW, without parasit drag, just using induced drag, and in the air it makes a very big difference to take a down line with a slow bipe Vs the same down line with an airplane that uses prop braking

trust me! you have to fly it to believe it! in my opinion a YS powered bipe is the way to go
How do you induce drag in a down line and come down vertically? Wiggle the tail?

Jim O
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Old 08-05-2012, 05:00 PM
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I would like to make one thing clear. Maybe Jim will confirm this. Induced drag is the drag caused by producing lift. Parasitic drag is all the other drag. When you are going straight down you are basically not producing any induced drag, as you are not producing lift. So all the drag is parasitic. Same as when you are going straight up. The lift is the prop. All the other drag is parasitic and is holding you back.

BTW, retracts do not significantly reduce the drag of the airframe unless they also use doors. Pete Goldsmith was one of the early proponents of fixed gear as he did wind tunnel tests that showed properly designed fixed gear created no more drag then retracts without doors but they had less turbulence then doorless retracts. This was particularly true with taildragger retracts as they put the holes in front of the high point of the wing, not behind it as in trike retracts.

And I really have to disagree with Brett's choice of props for electric. They've come a long way from running either 22x12's or 20x15's. I know of no one using either prop anymore. And the choice of what motor to use has come a long way. Inrunner's, outrunners, a variety of gear drives and Kv ratings have made it pretty easy to decide how you want to fly. Much more choice now then just a couple of years ago.

And I think it's hard to say how Brett would have done with another model. Maybe he would have won? Or maybe he would have been 8th? Impossible to say.

Looking at the new Unknowns, one thing is apparent. It is more like ETOC indoor foamy flying then pattern flying. And that event is dominated by tall fuselage monoplanes. Also, hard to run IC engines as it gets pretty smokey indoors!
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Old 08-05-2012, 05:05 PM
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If an airplane is designed to fly slow, it will go down slow, and I'm not saying "induce drag on a downline" I was just saying that if you need to have any drag on an airplane to make it slow, use induced drag, not parasite: and just to be clear: induced drag is the one that comes from generating lift, parasite drag is everything else that not (the landing gear, servos, the wing struts on a bipe, the big TE rudders, etc) I just beleive that any unwanted drag will do something wrong, specialy in an F3A airplane.
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Old 08-05-2012, 06:35 PM
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I hope I was clear, but if the wings are not producing lift, then all they are doing if the airplane is moving is producing parasitic drag.
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Old 08-05-2012, 07:18 PM
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Thinking of switching for the finals and unknown plane. Maybe fly something like this.

C
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Old 08-05-2012, 08:27 PM
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Hi Jim

One of the biggest misconceptions is that wings don`t produce lift in the up lines or downlines.
The wings never stop lifting! they just don`t lift quite as much in the up and down lines. but the drag never goes away.
Wings are 70% of all drag on a airplane, a bipe has two wings, 1.5 times the drag of a mono, plus 1.5 times the lift. The dynamics of a Bipe allows for not relying so much on the prop for drag breaking

You are right about the diameter being more effective on braking. I love large diameter props for breaking but, the more diameter you run the less pitch you can use ,this is where the breaking comes in, add pitch to that same prop, and you loose breaking. So the problem you run into is, with too much diameter for the breaking and,on a windy day, you don`t have the pitch or enough rpm to produce the pull needed to fight the wind, and keep up your speed and authority for many of the manuvers.

With a bipe, you increase the lift ( allowing you to fly slower speeds) the drag from the wings helps with the constant speed ( no zooming) and keeps the downlines slow.
The abilty to fly slow with authority gives you the flexibility to run the engine in the lower rpm range, and use the tourqe curve, this is what allows us to use more pitch to couple the torque and not rely on the diameter for breaking even in the downlines. This also gives you the ability to run the higher pitch for limiting the rpm to a specific number thus, enabling you to pass the sound test, but giving you the flexibility needed to fly in all conditions.

I`m not trying to say the prop does not help with the down line breaking is absolutely does,adding just 1/2 " has a dramatic effect on breaking, However the ability to back off diameter and add pitch is a big help with selecting the prop you "want" to run, verses the one you have to run! throttle resolution on the first 1/2 of the rpm range is now more smooth and duplicatable.
I have been whittling on props adding pitch, diameter, Ect for ten years now, I have so many custom props that work and just as many that don`t SO I know a thing or two about getting props matched to the airframe.
Diameter trumps pitch for the most part on Mono`s ,But Bipes are a whole new dynamic. My Bipe is the first one to experiment with this dynamic and take advantage of my theory. most of the bipes available today have the same drag profile as a mono due to flawed thinking.

As far as the fixed gear story, thats one of the Biggest BS lines I` ve ever heard it was told to me first hand many times but, Sorry, you have to disregard common sense to even consider that to be true.
First, the wheel wheels are in a area of the wing that mostly don`t do much, or even see much spiral slip stream (sorry could not help it)
Retracts are less drag period, I can make stories up about wind tunnels too! We started using fixed gear for drag! not to reduce it , now the story has changed to support the Habit! we are" only"stuck on them for convenience.
Given the opportunity to increase speed ,do you think the pylon guys would rather use fixed gear or retracts?
Why do you think retracts were used in the first place ,not to add drag, but to remove it.

You know It took about ten years for guys to start using my trim methods, after thousands of debates like this I freely give the information but people take offense to facts!, May be I`ll get a ten year head start on bipe designs and bipe trimming too!

Bryan



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Old 08-05-2012, 08:32 PM
  #74
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I love it Chip! ,But don`t you know those retracts will never work!!!
and that strake,, man just backward thinking


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Old 08-05-2012, 09:14 PM
  #75
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Tony ,You know it`s also impossible to say that if you put a set of wings on your arms and flapped really really hard! you might lift off the ground, or you might not ,it`s really impossible to say.
If you jumped off a cliff , and flaped really hard, you might induce enough drag to hit the ground at 2mph slower than if you didn`t flap at all it`s hard to say!!

If you flew your old CHallenge design, you might still win the next FAI team trials with 20 practice flights, and give lessons ! it`s not really possible to know!!

You know I`m joking, but I`m trying to show the absurd belligerant arguments you are making, nay saying just to nay say.picking pionts to argue without considering the big picture,or the resonable set of facts for our thesis.
It might be possible`s , are only used when you run out of facts, or you can`t support yours,so you just deflect. like sticking your fingers in your ears and saying nanni nanni BOO BOO, you were not even at the Nat`s you havent seen Brett fly the Bipe or even Jason fly his.

Ask some one who witnessed the flights with the experience to dissect what they saw, Then argue with them
It`s easy to argue from the couch with what if`s and may be`s but I make statements I can back up or I don`t make them at all.
my track record speaks for itself.

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