ArCeeFlyer

My Feedback: (1)

I did use the stock plastic coated wire that came with it. You just have to be very careful how you get it positioned and how you pull the tension into it. It's very delicate stuff. One thing I found was don't hit that wire with a heat gun. I did while tightening up the tail feather covering and the wire melted instantly and snapped apart. Luckily I had enough to splice it back together. I guess the reason they used such thin wire was obviously to keep the weight down. But I think it needs to be just a bit stronger just for handling it. Once it's in there, it should be fine. Mine hasn't shown any sign of wear yet at the rubbing points and I probably have a hundred flights on it by now. I did put some silicon grease at those points and that probably helped a lot.

T_om

Just a quick word here... you do not want regular "fishing line". You want one of the hi-tech spectra braids on the market. One of the brand names is "SpiderWire". That is just their brand name for their particular spectra fiber line.

I do a lot of offshore fishing and am very familiar with these lines. They are great. Low, low stretch and VERY abrasion resistant.

One thing that may or may not be applicable to using them in models is that just any old knot will not work. Spectra lines under high tension cut like razors and some knots will literally cut themselves apart when pulled tight. But I mean "tight" as in when a large loads (50 pound Dolphin, 100 pound Wahoo, Sailfish, etc.) are applied.

In model aircraft use, this should not be a problem but one other characteristic of spectra line MIGHT be. That is that it is slippery as grease. Knots such as a simple granny (overhand) knot will come undone by just slipping through itself. Always put a touch of CA on any knot you tie and you should be fine.

Pull-pull setups using quality spectra lines should be pretty much stretch-proof. If any loosening occurs, it is probably because the fuselage itself changes dimensions with changes in temperature.

Tom

SS2P

I flew mine today. I was dissapointed... I THINK I didnt have enough rudder throw or something but the plane didn't turn so well. I'm not sure how to get more throw cause I will definitly need some more. I quess I'm more used to 3d planes too! Rudder control is not BEST. I will just try increasing throw, although its damn hard cause Ihave double knots on there already. as for the the *fishing line* I will use a very small one. (5 pound or something) BTW, I do alot fishing too and I caught a shark yesterday

Paul

ArCeeFlyer

My Feedback: (1)

Polyhedral rudder steering gliders don't always turn the moment you apply rudder. Depending on the wind direction and strength affecting it, at times I can hit full rudder and it takes a few seconds to respond, and then when it does, it can go quick. It can require thinking ahead some in turning maneuvers, kind of like a large ship at sea. I think that just serves to make it more challenging. In calm air it turns nicely, but nothing like 3D planes for sure. I think what happens in a crosswind with the polyhedral, the wind tries to roll the plane, say left if the wind is right to left, thus making it hard for the rudder to turn it right, an eventually it will yaw around. If you're not use to these type of gliders, they can seem sluggish and unresponsive. Once you get use to it, it can be a rewarding flying experience, especially when you get in that first big thermal. I did put in all the rudder throw I could on mine. It definitely needs it.

SS2P

I added more rudder throw and flew again. Nice! I made many launches but I haven't tryed the high launch yet cause these flights were just to see if everything works. It flew fine. I didn't found any thermals yet.

+

Stable

glides well

balsa- Looks way better than my foamies

-

Control horn isn't protected (mine broke off)

Rudder should be more sensitive.


I can't wait to get in some nice thermals. By the way, do you have any good ideas how to catch thermals well (tips)
And also I wanted to ask you what radio are you using? I'm looking for a new one since my old one stinks, its a 5 ch. without a screen.
What would you recommend.

Have fun!

Paul

ArCeeFlyer

My Feedback: (1)

Oh ya, I forgot about the horn. I had put a tail skid on mine to protect it on landing.

I agree, a bit larger rudder would be better.

I have JR XP8103 computer radio. I have always liked having a versitile computer radio so I'm pretty much ready for anything. The newer JR XP9303 is very nice.

If you can get the glider over land that heats up quicker than the surroundings, like a plowed field, then when you see the glider start climbing some, start doing circles to stay in it. Of course, if there is a breeze, the thermal may be moving laterally also. It a very dynamic process in all the ways thermals are generated. I'm just a novice when it come to thermaling and I'm sure there are experts here that could explain them in detail.

evan-RCU

Alan, do you ever go to Columbia to fly slope?

SS2P

Ok I made a tailskid to protect that and I'm ready to go now. It looks very warm outside and I bet there are thermals out there right now. I will use the high launch too!

I'm outta here!

ArCeeFlyer

My Feedback: (1)

I've been up there a couple of times but never flew anything there yet. I still would like to try flying there sometime. Slope flying looks like a blast. The last time I was there, the slope winds were about 30 mph and the wind chill must have been in the single digits. Quite exhilarating.

Bax

My Feedback: (11)

Just a note. The wind direction makes absolutely no difference in how well a model turns. CHANGES in wind velocity will affect a model, but the direction...no, not when it's steady. Your perception of how the model's flying is what gives the impression of differences in performance or handling based upon which way the model's flying in relation to the wind direction. You're flying something that's in a moving inertial system, and you're on a fixed point outside of that system. In steady conditions the model does not 'feel' any wind at all. The model only feels the changes in wind velocity.

Once in the air, the model handles flying in winds 40, gusting to 50 the same as flying in winds of 5, gusting to 15. Now, its path over the ground would be significantly different, but in the air, the model sees them as the same....you're the one who sees it differently.

ArCeeFlyer

My Feedback: (1)

I think the issue of how wind speed effects how planes turn has been an ongoing debate seemingly forever. At the risk of getting that ball rolling again on this thread, and with the utmost respect for your opinion, I would just like to state something about it for you to consider. Way back I used to think the same way, that just because the air mass is moving it shouldn't make any difference on how a plane turns. But I could not understand why when I would turn a plane downwind it would tend to lose lift momentarily and when turning upwind it would gain lift momentarily. Finally one day a friend pointed out the answer to me. Momentum! At a given ground speed a plane has a certain amount of inertia due to its mass. A plane flying at a set air speed into the wind will have a slower ground speed and less inertia, and with the wind, a faster ground speed and more inertia. When the plane turns downwind its inertia is momentarily too low to maintain the original airspeed and must gain it back by increasing its ground speed. Vice versa for an upwind turn. That's why when I have a dead stick downwind, I always have success in turning the plane back upwind using its surplus of inertia to keep it flying longer and slower for an easy landing. I've seen plenty of dead sticks turn downwind and drop like a rock. Another example to help visualize this would be to picture a plane maintaining an airspeed of 20 mph into a headwind of 20 mph. The ground speed would be 0 mph and the inertia would be 0. If you could just stop the wind suddenly to 0 mph the plane would suddenly have 0 mph airspeed and would have to fall into a dive to get it back in the still air. I believe this theory to be factual and I have watched it prove out in actual flight time after time. I fly my planes with this in mind with great success. So, respectfully, that's my take on it from experience and not intended to be argumentative and welcome any thoughts on it. Although I won't offer any further rebuttals here since it's a little off topic. I'm sure there are plenty of threads about this already that would be interesting reading.

SS2P

I just flew mine on a slope and I really liked it. It flew well and I caught a large thermal that threw me way up high. I flew for one hour.
This plane is a fun, cheap way to get flying. I made a couple of changes including large servo arms and little changes in canopy+ diffrent control horns. Highly recommend it.

Paul

ProScaleRc

Recently a friend of mine talked me into buying a Fling. I was hesitant because I’m always concerned about planes that are cheap… remember the old saying, ‘you get what you pay for’.

Well this little cheap sailplane has blown me away… it’s given me hours of joy. There have been numerous occasions where it’s thermalled that high, it was impossible to see.

I own a 3.8m carbon/fibreglass H-model DG-1000, and trust me the fling has been so much more fun to fly.

I’m picking up a 2m Fling this week… hope it’s as good as it’s little sister.

SS2P

Good! Give us a report please!

goldsticker

Actually the airplane has the same inertia on the ground as it does in the air. The direction of flight does not change the inertia. Inertia is a physical property of the mass of the airplane and is constant. The term you need to use more consistently is momentum, which is the product of mass times velocity. Now the important question is which velocity do you use to calculate momentum, ground speed or airspeed? You have raised an interesting point. It is a good question.

In the situation when the mass of the air is unaccelerated... moving at a constant velocity with no gusts. You can pose the flight dynamics problem (momentum) from either the ground reference coordinate system or with respect to the moving air coordinate system. Since both coordinate systems are unaccelerated they are called !QUOT!inertial coordinate systems!QUOT! Here is the important part! The requirements of the physics of the problem is that you MUST get the same answer to the problem no matter what coordinate system you choose to do the math, (this is entirely consistent with our expectations). By the same answer I mean consistent within the differences between the coordinate systems. Thus we can calculate the answer with respect to the air and transform the result into the ground reference coordinate system and get the same answer as we get when we calculate the answer in the ground reference coordinate system. (This works as long as both coordinate systems are unaccelerated.)

To the R/C pilot the important differences are the visual clues that an pilot on the ground gets while flying a model airplane. We can't see the air so we can't judge what is happening to the airplane with respect to the air. Our only data to process are the visual clues we get with respect to the ground. This biases our judgment and how we fly.

If the wind is blowing at a constant velocity, the airplane is unaccelerated by the wind the airplane can't tell if it is making an upwind turn or not. Neither can a pilot in a full scale airplane at ALTITUDE. Many novice full scale pilots have gotten in trouble in the landing pattern because they take cues from the airplane's drifting ground track and try to horse the airplane back to the ground track they wanted and end in an accelerated stall at low altitude, perhaps fatally. Model airplane pilots make the same mistake from a different point of view. The R/C pilot CAN tell if the turn is upwind or downwind and it is hard to ignore the visible differences between them.

Thankfully, humans are smart and adaptable and we learn to compensate, (at least the successful humans). It doesn't really matter if your reason for and/or explanation of why you are changing your flying habits is correct when you make a downwind turn instead of an upwind turn. The result is to succeed, you must learn to compensate correctly. I observed this today; A new pilot at the slope kept insisting upon making downwind turns at low level. I didn't have a chance to speak to him, but others did. Had he told me that there is no difference to the airplane whether or not the turn was upwind or downwind, I would have agreed with him. But to us on the ground there is a difference, a big difference; the downwind turn covers more territory; more than a new pilot often realizes. It is largely the difference in ground speed and ground track that plays games with our perception and our piloting judgment. This new pilot ended up hitting parked cars on the other side of the road on two separate occasions. I hope he learns his upwind/downwind lesson soon. I don't care what coordinate system he uses or how he justifies it to himself!

Three things to think about:
1) We often assume the earth is not moving. In fact it is moving at an amazing velocity. Remember it has to cover a very large orbit around the sun in only 365 days. It is really hauling... So the airplane is flying at a constant speed in the air which is moving at a constant speed relative to the earth which is moving at a constant speed around our sun. The sun is moving around the center of our galaxy... need I go on? Now how do we solve the momentum problem? Which velocity to use? Fortunately, all of these systems are arguably unaccelerated. Our inner ears can't tell we are moving. The math doesn't care that the air or the galaxy is moving, neither does the airplane. However to the pilot/observer on the ground it is an important difference, one that we must learn about and compensate for.

2) NASA would never fly an autonomous drone aircraft from the ground perspective. The equivalent of a computer pilot is in the aircraft flying it from the aircraft's perspective. FLYING AN AIRPLANE FROM THE GROUND PERSPECTIVE IS TOO HARD. Short of getting a pilot's license there is nothing we can do about it, we have to fly from the ground perspective; The hard way!

3) This whole discussion is tossed out the window for a wind gust. For now the air mass is accelerated. I don't even want to think about the mathematics of that... this is why we keep extra airspeed in gusty wind. [Problem solved, who cares about the details?]


In short, your explanation is not up to snuff but that is not so important (unless you work for NASA). What is important is that your are aware of the problems of flying an aircraft from the ground perspective and that you are compensating correctly. You aren't crashing into my car and we can be friendly at the flying field.

cheers
goldsticker.

goldsticker

Back on topic...

I agree it is a great airplane. I fly slope and it will fly when the wind is light and only floaters can catch the lift. It does fast and slow very well. I believe it will handle winds that would retire many floaters. One of the guys calls it a popcorn fart, (really light). I did read some complaints about its turning ability so I did make changes. Here is what I did.

1) I used thin music wire/park flier pushrods instead of the pull-pull cables. The pushrods run on the outside of the tailboom bound in place with a braided fishing line at both ends and CA'd every where else. I had to make long narrow slots in the fuselage between bulkheads (under the wing) to get the pushrods to the outside. The throw on the rudder is substantial and I have no complaints about turning with the stock rudder.
2) I used micro/parkflier nylon control horns.
3) The dihedral joint on my wings was mechanically a bit sloppy so I epoxied a fractional ounce glass tape at the wing seam to add strength.
4) After several weeks flying, I discovered a rolling tendency at high speed that was traced to a built in twist in the wing poly tips. The stock wing covering was not strong enough to take the twist out with a heat gun so I recovered the wing. Problem solved.
5) I didn't trust the rudder butt joint so I added a 3/16 inch triangular fillet between the rudder and elevator.
6) I always use a piece of blue painters tape as a hedge against the canopy coming loose in a hard landing.

I had to add some nose weight to balance the pushrods so my plane is about an ounce over the max weight listed in the plans (via a $5 kitchen scale) but it still performs quite well. I have used the mini-high start on several occasions and it tracks into the sky like it is on rails. I've had to repair the fuse nose twice due to hard landings, the glass is quite thin! Its stronger now and I need less nose weight. It really is too small for anything but the recommended airborne equipment, especially the RX and battery. Go with the 375 mA 2/3 AAA pack as recommended. Nothing else will fit. I have an extra flight pack to switch with if needed. But I've never done so. It seems nearly an hour total with the switch on is all I can handle.

cheers
Goldsticker

ArCeeFlyer

My Feedback: (1)

Goldsticker, I enjoyed reading your wealth of input about your take on how the wind affects a plane. Sorry about using the term "inertia" out of context. I think it's a common mistake many make and I stand corrected. Thanks for pointing that out for me. I took some time to brush up a bit on Newton's 3 laws of motion. I should have said something like, "The plane's state of inertia is no longer retained as the forces of wind during changes in the plane's direction causes its momentum to change, thus causing a momentary change in air velocity until it reaches another state of inertia again." "Inertia" being Newton's first law of motion where an object persists in its state, be it uniform linear motion or at rest, until external force/s cause it to change. And the term "momentum" (mass x velocity) is really the key issue I was trying to enlighten upon. Being one of the variables in Newton's second law of motion, momentum of a plane is directly affected by, among other forces, wind velocity and direction in relation to the plane's changes in velocity and direction. It's important to know I'm talking about changes. The slower and more gradual a plane's change in direction in a given wind velocity and direction, the smaller the momentary increase or decrease in momentum. The faster and more abrupt a plane's change in direction in that same wind, the greater the momentary increase or decrease in momentum. It's that momentary change in momentum that increases or decreases the plane's airspeed momentarily until it can regain a state of inertia again. And, of course, that all fits in to Newton's third law of motion where for every action there is an equal and opposite reaction. Another thing to keep in mind is this is happening dynamically throughout a change in direction. Not only its forward motion, but also all 3 dimensions can be involved. A plane vigorously turning from a headwind to a tailwind must traverse through the crosswind as well and until that crosswind can return the plane's lateral momentum to a state of inertia, which it had while flying straight before the turn, the tail will yaw with the wind through the turn, inwards from the upwind side and outward from the downwind side. The same goes for loops parallel to the wind direction, where the pitch of the plane is momentarily affected as the z-axis of the plane’s momentum tries to return to a state of inertia in that brief period through the loop. Loops perpendicular to the wind will not be affected once the lateral momentum's inertia is reached. It would be a lot like flying straight and level perpendicular to the wind. Of course, the loops would look like a helix from the ground. Many times I’ve flown in winds strong enough to give my plane negative ground velocity, or momentum in the reverse direction when flying into the headwind. It’s not hard to visualize what’s going to happen when performing a normal 180-degree turn at that point. It’s going to drop like a rock until the plane can build up forward momentum, and in that situation, it’s going to need a healthy dose of thrust to do that before it stalls big time. In my explaination earlier about the polyhedral wing rolling with the crosswind, these laws of motion can be applied. Looking at the glider wing end on, that profile, when perpendicular to the wind, has a "center of pressure" above the fuse and during a turn at that phase should tend to roll the wing over with the crosswind momentarily until the lateral inertia kicks in. That makes the rudder seem ineffective for a moment as it tries to roll the glider the opposite way. As far as getting visual misconceptions from the ground, just because I'm standing on terra firma in a fixed position doesn't mean I can't comprehend the wind dynamics of what is going on above me. I have no problem with that, and I can easily differentiate ground-to-sky visual anomalies from the plane's true movements through space with a moving air mass. It's not that hard to grasp. Every time I'm at the field on a windy day, I observe these momentum/wind physics going on all the time and I can easily take a plane that is sensitive to them (so the effects are easier to see) and reproduce them at will. I enjoy flying in extremely high winds where these physics are greatly amplified and I experience and even experiment with them often. There are all kinds of examples that people probably witness all the time. I heard so many ask why their plane, in a brisk wind, loses lift briefly (momentarily decreases air speed) on a downwind turn and gains lift briefly (momentarily increases air speed) on an upwind turn. I know they are not imagining it. I know I'm not. I watch 3D planes pull up quick into a hover in a brisk side wind and they are fighting to keep it vertical with the rudder until the plane starts to drift with the wind at which point the plane's lateral momentum reaches inertia and less rudder inputs are needed to keep it vertical as it drifts across the ground. Of course, if they want to keep it in front of them, they have to maintain a yaw angle to compensate for the side wind, the makings of knife edge flight without moving and reaching yet another state of inertia. I watch crosswind take offs, left or right, yaw (more left than right due to torque and/or prop pitch a.o.a. factor) into the wind briefly after leaving the ground (obviously not compensating with rudder) and then reaching inertia tracking off at a steady angle from the ground point of view and obviously straight as the moving air mass is concerned, until the next turn, breaking briefly from inertia again. Of course, in dead calm air, all these momentum/wind gremlins basically vanish.

I was curious about other threads on here that may have discussed this topic and this one was quite interesting.

[link=http://www.rcuniverse.com/forum/m_388652/mpage_3/key_/tm.htm]http://www.rcuniverse.com/forum/m_388652/mpage_3/key_/tm.htm[/link]

It wasn’t until about post #64 where some touched on this subject and shared some points of view similar to mine. The whole thread is quite an intense aerodynamic discussion originally started about an article in January 2003 of Model Aviation. You probably won’t be surprised that I was appalled at how misleading the article was, in my opinion. The self-serving examples they used were so far off scale and unrelated it made the physics I’m talking about appear to be non-existent. How convenient for the article. We have perfect examples flying around right in front of us at the flying field. It doesn’t matter that the universe is expanding, our galaxy is swirling, our planet is revolving and rotating, all adding to the final momentum factor of a plane. All those celestial bodies are mostly in a state of inertia set forth billions of years ago and I do understand that the motions of each are independent of each other. We’re talking about a momentum issue that’s happening right in front of us from point A to B, a relationship of changes in momentum, the all important air velocity a plane depends on, and the external forces of wind. They cited the example of the fly in the moving car. Its mass is too small to show the effects, not to mention the incredible power to weight ratio of a fly. The bicycler doing 10mph circles on the 860 mph Earth surface. He’s not a plane. The Earth and the bike are at inertia. No mention of wind. Although the bike doesn’t require wind to stay up, add a 10-mph wind and see how quick he has to increase and decrease his pedaling to maintain a steady velocity of 10 mph against the drag and the push. It’s more of a reverse situation compared to a plane doing circles where it needs to maintain air velocity for level flight. The bicycler just wishes it would go away when it’s against him and welcomes it when it’s with him. I know the feeling from riding over a thousand accumulated miles on my road bike. It’s a poor example compared to a plane in powered flight changing directions through wind.

Again, I respectfully submit my take on this issue not intending to be purely argumentative. And I really appreciate your civility. So many debatable issues like this get out of hand on here sometimes, albeit they can be entertaining reading. I respect your beliefs and I am comfortable with mine. Too bad this topic didn’t get started on its own thread. I’m sure it’s bound to attract a lot of input as I thought it might. Might as well have at it. That’s what the forum is for anyway. I think I was plenty thorough and I really don’t care to try and clarify it any further myself.

I wish you great flying always, regardless of what Newton says. [sm=wink_smile.gif]

ArCeeFlyer

My Feedback: (1)

Hey, speaking of wind, man we can sure put some out there can't we? LOL. Just kidding! Seriously, I flew the 48" Fling in maybe about 15-mph wind possibly gusting to 20 mph. I have to tell you guys it was a blast. I could fly it like a kite on the high start for a sustained period, but eventually would come off. Once flying in that stuff, it's pretty cool to try and keep it up as long as you can and still land close to the pits. That strong of wind required a steady touch of down elevator to keep it from landing way off downwind. You can easily fly it backwards at about 5 mph, maybe more, in relation to the ground of course. Trying to get it to turn at times in that stuff can get pretty exciting. It's a very versatile glider. I’m very happy with it.

SS2P

Hey ,

I 'm thinking of putting ailerons to my fling. I will build them from balsa and plywood and make 2 servo pockets. I will obviously use light stuff in it. I will will use ailerons also as spoilers (bring both of them up. I'll give ya a report later.

goldsticker

There is just enough room aft of the battery in the fuselage to put a nano servo. You might try to run the ailerons from there, the old fashioned way, with a single servo. I suggest you stick with the stock design until you've flown it a bit. You might be satisfied with it and leave it as-is.

goldsticker

goldsticker

Got home late so I haven't had time to fully digest your thoughts. We do agree that the momentum can only change if there are external forces on the aircraft. There are certainly pilot induced external forces on the aircraft as it turns. The question is can we determine that the turn causes a change in the wind forces?

The cyclist example is interesting! 820 mph... FASTER THAN THE SPEED OF SOUND! How come no sonic boom?


Goldsticker

ArCeeFlyer

My Feedback: (1)

Hey that's great. And I think you summed up this age old argument in one perfect question. I think that's what it all boils down to.

LOL! In their example in that article they were talking about the latitude of where that particular bike was located and the surface of the Earth at that point was moving 860 mph. Of course, the atmosphere around the bike is moving with it at that speed assuming he's in still air. Heck, if the bike could go a little more than Mach 1, forget the sonic boom, he might start to feel a bit warm with such poor aerodynamics. [sm=lol.gif]

ProScaleRc

I flew my 2m Fling for the first time on the weekend... very nice. It's flies beautifully, much better than the little Fling. The only disadvantage is size... the little Fling is perfect for any park, but the 2m needs big open spaces.

SS2P

Cool. I'm sure I will get that one too! It would be perfect for my cliff