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Old Dec 01, 2012, 08:05 PM
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HoosierGuy's Avatar
United States, IN
Joined Jan 2012
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Ok, I bought some DAB Fast'N Final Lightweight Spackling. Never used it before. I also bought a can of Great Stuff Big Gap Insulating Foam Sealant. Has anybody used Great Stuff to fill big gashes in wings? I've never used it so I'm wondering if it's safe to use on my foamy wings.
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Old Dec 01, 2012, 08:12 PM
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United States, ID, Burley
Joined Mar 2012
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Quote:
Originally Posted by HoosierGuy View Post
Ok, I bought some DAB Fast'N Final Lightweight Spackling. Never used it before. I also bought a can of Great Stuff Big Gap Insulating Foam Sealant. Has anybody used Great Stuff to fill big gashes in wings? I've never used it so I'm wondering if it's safe to use on my foamy wings.
try it on a small piece of foam first. on the Spackle you can layer it to fill but it has to be completely dry before the next layer . when it sanded down with 200 grit or finer you cannot tell where the break was
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Old Dec 01, 2012, 11:47 PM
The Sequel
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Australia, VIC
Joined Sep 2011
1,340 Posts
Quote:
Originally Posted by Terry Grau View Post
I currently fly the P2000 with 4 different wings, 2 aileron and 2 poly, up to 2750mm span.
I have added double the area to the rudder and found no advantage to the sailplane and removed the extension.
If it will thermal well with a poly wing and rudder/elevator only for control then as a sailplane I think the rudder is adequate.
Probably not effective enough for slope style aerobatics, but that's not the primary purpose of the airframe.
What I need is about 100 watts more motor for the big wings. Motor suggestion appreciated.
i posted my set up, which teamsherman took up, refer post 2426, page 162. Yet to here from you TS hope it's working out. You are looking at 550-600 watts on 4s and nice thrust. Flew today and yesterday in 20-30 km/h sea winds, awesome conditions, was getting no response from ail and elevator during high speed down wind runs, but suprisingly that rudder woud give me some feel? Go figure? New top speed on the gps too. Great weekend of flying with the phoenix, a st fox and the hk rare bear. Brendan
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Old Dec 02, 2012, 07:51 PM
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United States, ID, Burley
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SO since the Phoinex got built it has been blowing VERY hard and raining and hailing side ways here in Idaho. You know I DA HO U DA PIMP Idaho lol
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Old Dec 02, 2012, 08:16 PM
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Fairplay, South Park, CO
Joined Sep 2005
1,608 Posts
Friends,

I had some clean smooth (cool) air today for doing some further test flying of my Phoenix 2000, and am finding that it's flying well. I've possibly been a bit harsh in my comments about the rudder previously... I'm just used to quicker rudder control response with other gliders which I've designed & built.

Rudder response is what I'd characterize as delayed, lagging (unless you're really hauling ass , under power or possibly while flying higher speed slope flying conditions.) At normal thermal hunting cruising speeds, you simply put in some rudder deflection input, and wait a bit for it to respond.

I've actually mixed in A>R 20% for thermal flying; I can still initiate a turn with rudder (if I'm a bit patient) then feed in a modest amount of opposite aileron to keep the bank angle shallow while turning.


Since I'm not using the flaps at this time, I have ironed hinge line gap covers over the flap hinge line gaps to minimize possible drag from air turbulence over those gaps.

I've also made up some gap covers for the aileron hinge line top gap (which is fairly wide.) Hard to say for certain at this stage, but after today's flying, I'm thinking that the drag has been reduced, & the power-off glide efficiency is thereby improved. These floating hinge line gap covers are simply made from two layers of clear laminating film (with the adhesive side face-to-face for the area over the gap & moving aileron) with the top layer extending in a single layer, adhesive side toward the wing, forward from the hinge line gap another ~3/4", where it's then simply ironed down to the wing foam.

You have to keep the temperature on the covering iron down when laminating the two layers to each other, and while ironing it in place on the wing. The bond is very strong at a low temperature which does not distort / damage the wing EPO foam if you set the temperature correctly.

I'm using spoilerons to reduce landing distances some. With the weight of this glider & it's ability to carrying a fair amount of energy, it takes some distance to bleed off the speed. The spoilerons are effective for where I'm flying; if you work from a tighter landing area, activating the flaps will allow for landing in less space than what spoilerons will allow for. (You still need to set up your landing approach right, whichever way you fly the Phoenix.)

The ideal glide speed is faster than some similar gliders in this size / class, and it really doesn't maintain altitude as well if you try to slow it down a bit too much... it'll go into a very gradual 'porpoising' if you have too much up trim in, & won't glide as efficiently when slowed down below a certain point. The Phoenix does like to move out & cover more ground, and that's nice!

All in all, I had a good day flying this aircraft today in smooth cool air which allowed me to really evaluate how it responds to small changes in trim. While it'll likely fly managably with the CG set across a range, I'm also expecting that there will be a fairly narrow CG range where it will actually glide most efficiency.

VIKING
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Old Dec 03, 2012, 02:28 AM
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Thank you, Viking, for your detailed report.
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Old Dec 03, 2012, 04:36 PM
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United States, IN
Joined Jan 2012
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I used that foam in a can stuff to fill those gaps. It set up overnight. Now I used that spackling to coat (go over) the foam stuff. The foam in a can seems to work but it's softer than the wing. I'm not sure if it will harden up over time or not. Still, that foam in a can might be useful for more repairs. It might be worth investigating this product more for foamy wing repairs.
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Old Dec 03, 2012, 05:05 PM
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United States, ID, Burley
Joined Mar 2012
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Originally Posted by HoosierGuy View Post
I used that foam in a can stuff to fill those gaps. It set up overnight. Now I used that spackling to coat (go over) the foam stuff. The foam in a can seems to work but it's softer than the wing. I'm not sure if it will harden up over time or not. Still, that foam in a can might be useful for more repairs. It might be worth investigating this product more for foamy wing repairs.
sweet ! pictures ? Im loading the plane up and going to maiden it this afternoon. Got the 2.5m wings so hope she floats like a humming bird ill do the go pro video and try to keep it close enough to see, go pro isnt that good for this as it makes everything look further away
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Old Dec 03, 2012, 08:47 PM
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Got out for a maiden flight, it is a short video as i had to land and do some trimming. This thing is fast,very responsive,and will float a long time without motor. On second flight i almost lost it, ill post that video as well. It dropped off to the left hard,i think it is because i charged battery and got it back in off center,no idea what else would do it as trim was all good. Ohh and second flight i landed it and wing caught a small tree,zero damage but that second flight had me jittery after almost hitting the dirt hmmm i dont what utube does but after uploading everything is even farther away. here is first flight, seems if you go up to HD under quality and then go full screen it is way closer and easier to see.
GOPR0063 (3 min 44 sec)


And the almost crash
GOPR0064 (3 min 36 sec)


Found out if i change the setting resolution on gopro it will be more zoomed instead of a 170 deg field it goes to a 127 deg if it ever stops raining,snowing and blowing ill give it a shot
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Old Dec 05, 2012, 10:40 AM
Seeker of Thermals
botulism's Avatar
United States, MT, Kalispell
Joined Aug 2004
665 Posts
Quote:
Originally Posted by viking60 View Post
Friends,

I had some clean smooth (cool) air today for doing some further test flying of my Phoenix 2000, and am finding that it's flying well. I've possibly been a bit harsh in my comments about the rudder previously... I'm just used to quicker rudder control response with other gliders which I've designed & built.

Rudder response is what I'd characterize as delayed, lagging
...
Viking, regarding your previous posts about the P2K's anemic 'turn' response with the rudder.

The sailplanes you specifically point out in your previous posts as having much better turn response than the P2K (the Spirit 100, the EZGlider, and your 'more recent designs...flat-built wings with elliptically up-swept wing tips' all have one thing in common. Polyhedral. Or upswept wing tips (the little anti-vortex wingtips on the P2K don't count as such).

The reason you think the P2K has anemic rudder response is because it's doing exactly what it was designed to do. The rudder is designed to yaw the plane, not initiate turns. On a plane with flat wings, the only thing that's going to roll it (on its longitudinal axis), is the ailerons. Think of a pylon racer. They long ago discovered the quickest (most efficient) way to turn was to bank it (so the wings are 90 degrees to the horizon) and yank it (full up elevator). Pylon racers (and a lot of slope sailplanes) don't even have rudders.

Think how a sailplane with polyhedral (or even dihedral) turns. You yaw the plane left or right with the rudder, and viola, the wingtip facing into the direction of flight
goes UP, just the same as if it had ailerons, and you had rolled it one way or the other. That's because of that big plank on the end of the wings facing into the airstream, forcing the wing up.

A flat wing has no big surface to initiate the roll, so it's going to merrily cruise
on down the highway, yawing to the R or L, but not turning. Meanwhile, you're
thinking 'golly, that thing sure doesn't turn (roll) as well as my xxx'.

As far as 'initiating a turn with the rudder, and then applying opposite aileron' - that's called a slip, and is only useful to increase the frontal area of the plane, which increases the drag, giving it a worse glide
ratio. Only really useful if you're trying to lose altitude, eg. when landing, or to get out of a monster thermal.

You may have found that works for you while turning in a thermal, but 'conventional wisdom' (I hate that term) says it's not doing what you think it's doing, nor what it was designed for ie. a large flat circle.

So, there you go. I'm sure you'll have comments.

btw, I can't believe the weather there in CO this winter, isn't South Park usually covered in snow, with fierce 100 MPH winds in the winter?

--
Greg
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Old Dec 05, 2012, 11:21 AM
CURIOSITY Has Landed!
Fugitive_Bill's Avatar
Sydney, Australia
Joined Jul 2005
1,170 Posts
Botulism (Greg):
Well put. You nailed it. Even I could not have said it better.
I like your thinking!
B!LL!
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Old Dec 05, 2012, 02:46 PM
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United States, ID, Burley
Joined Mar 2012
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Quote:
Originally Posted by botulism View Post
Viking, regarding your previous posts about the P2K's anemic 'turn' response with the rudder.

The sailplanes you specifically point out in your previous posts as having much better turn response than the P2K (the Spirit 100, the EZGlider, and your 'more recent designs...flat-built wings with elliptically up-swept wing tips' all have one thing in common. Polyhedral. Or upswept wing tips (the little anti-vortex wingtips on the P2K don't count as such).

The reason you think the P2K has anemic rudder response is because it's doing exactly what it was designed to do. The rudder is designed to yaw the plane, not initiate turns. On a plane with flat wings, the only thing that's going to roll it (on its longitudinal axis), is the ailerons. Think of a pylon racer. They long ago discovered the quickest (most efficient) way to turn was to bank it (so the wings are 90 degrees to the horizon) and yank it (full up elevator). Pylon racers (and a lot of slope sailplanes) don't even have rudders.

Think how a sailplane with polyhedral (or even dihedral) turns. You yaw the plane left or right with the rudder, and viola, the wingtip facing into the direction of flight
goes UP, just the same as if it had ailerons, and you had rolled it one way or the other. That's because of that big plank on the end of the wings facing into the airstream, forcing the wing up.

A flat wing has no big surface to initiate the roll, so it's going to merrily cruise
on down the highway, yawing to the R or L, but not turning. Meanwhile, you're
thinking 'golly, that thing sure doesn't turn (roll) as well as my xxx'.

As far as 'initiating a turn with the rudder, and then applying opposite aileron' - that's called a slip, and is only useful to increase the frontal area of the plane, which increases the drag, giving it a worse glide
ratio. Only really useful if you're trying to lose altitude, eg. when landing, or to get out of a monster thermal.

You may have found that works for you while turning in a thermal, but 'conventional wisdom' (I hate that term) says it's not doing what you think it's doing, nor what it was designed for ie. a large flat circle.

So, there you go. I'm sure you'll have comments.

btw, I can't believe the weather there in CO this winter, isn't South Park usually covered in snow, with fierce 100 MPH winds in the winter?

--
Greg
i guess im just used to a rudder not used to turn, had no problems when i flew it. very responsive and will turn standing on a wing,with ailerons
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Old Dec 05, 2012, 08:22 PM
Row 0, Seat A
G550Ted's Avatar
Savannah, GA
Joined Jan 2008
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Quote:
Originally Posted by botulism View Post
Viking, regarding your previous posts about the P2K's anemic 'turn' response with the rudder.

The sailplanes you specifically point out in your previous posts as having much better turn response than the P2K (the Spirit 100, the EZGlider, and your 'more recent designs...flat-built wings with elliptically up-swept wing tips' all have one thing in common. Polyhedral. Or upswept wing tips (the little anti-vortex wingtips on the P2K don't count as such).

The reason you think the P2K has anemic rudder response is because it's doing exactly what it was designed to do. The rudder is designed to yaw the plane, not initiate turns. On a plane with flat wings, the only thing that's going to roll it (on its longitudinal axis), is the ailerons. Think of a pylon racer. They long ago discovered the quickest (most efficient) way to turn was to bank it (so the wings are 90 degrees to the horizon) and yank it (full up elevator). Pylon racers (and a lot of slope sailplanes) don't even have rudders.

Think how a sailplane with polyhedral (or even dihedral) turns. You yaw the plane left or right with the rudder, and viola, the wingtip facing into the direction of flight
goes UP, just the same as if it had ailerons, and you had rolled it one way or the other. That's because of that big plank on the end of the wings facing into the airstream, forcing the wing up.

A flat wing has no big surface to initiate the roll, so it's going to merrily cruise
on down the highway, yawing to the R or L, but not turning. Meanwhile, you're
thinking 'golly, that thing sure doesn't turn (roll) as well as my xxx'.

As far as 'initiating a turn with the rudder, and then applying opposite aileron' - that's called a slip, and is only useful to increase the frontal area of the plane, which increases the drag, giving it a worse glide
ratio. Only really useful if you're trying to lose altitude, eg. when landing, or to get out of a monster thermal.

You may have found that works for you while turning in a thermal, but 'conventional wisdom' (I hate that term) says it's not doing what you think it's doing, nor what it was designed for ie. a large flat circle.

So, there you go. I'm sure you'll have comments.

btw, I can't believe the weather there in CO this winter, isn't South Park usually covered in snow, with fierce 100 MPH winds in the winter?

--
Greg
Good post Greg. I was going to comment similarly but was too lazy to do so.

I find it unfortunate that so many model fliers think the rudder is the appropriate control to turn an aircraft in flight. It's not. Aircraft aren't like boats, they operate in 3 dimensions not two and the dynamics are different. As you point out the proper way to turn is to bank, rudder to be used to turn when on the ground/water and for specific maneuvers like a stall turn. Use of rudder beyond that needed to counter adverse yaw merely creates drag as you stated (although what you describe is actually a skid not a slip, but with the same adverse result).

Ted
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Old Dec 05, 2012, 09:49 PM
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United States, ID, Burley
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Originally Posted by G550Ted View Post
Good post Greg. I was going to comment similarly but was too lazy to do so.

I find it unfortunate that so many model fliers think the rudder is the appropriate control to turn an aircraft in flight. It's not. Aircraft aren't like boats, they operate in 3 dimensions not two and the dynamics are different. As you point out the proper way to turn is to bank, rudder to be used to turn when on the ground/water and for specific maneuvers like a stall turn. Use of rudder beyond that needed to counter adverse yaw merely creates drag as you stated (although what you describe is actually a skid not a slip, but with the same adverse result).

Ted
well now i like to use rudder to turn the gliders as well as when taking video from a glider,it is needed to keep wings level, i use rudder and aileron to keep things as level as possible.Viking isn't wrong it is just that we all have our own way of doing things,don't make it wrong ..
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Old Dec 05, 2012, 10:34 PM
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I learned to fly long before there were programmable radios and had a private license before I ever tried to fly an R/C model. I have always felt uncomfortable trying to fly anything without 3 axis control. While most 3 axis planes can be flown "bank and yank" it behooves one to learn to coordinate controls. Aileron establishes bank. Elevator controls the rate of turn. And rudder controls attitude by raising or lowering the nose in a banked turn.

Adverse yaw is a particularly common problem with sailplanes. Any lifting airfoil will suffer adverse yaw to some degree but a high aspect ratio with ailerons at the tips of the wing makes it worse. Differential aileron throw, with more up travel than down, is a big help but one still must use rudder in a turn for best results. But? Rudder is not the primary control for a coordinated turn unless a plane is designed for 2 axis control with lots of dihedral.
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