[RCSE] (from Tord) Re: Fun at the cane field
Hi Paul, Both me and the wife loved your text! Haven't yet got any 2.4 GHz stuff (I'll just swap the transmitting part in my trannies and get suitable rx's), but is eagerly awaiting! Those small birds, that seem black late afternoon, and appear in huge clouds close to sunset, are starlings, most likely, looking for somewhere to settle for the night! A cane field, a stand of reeds, stands of thick bushes, in short, anything free of predators and very dense, is their favourite sleeping quarters (In Britain they tend to move into the southern cities in wintertime - Bath is said to have the majority of Northern Europe's starlings disrupting the citizens' sleep a few months each winter! Therefore electrified roofs, windows sills, et cetera, everywhere in that old, Roman, city! A few decades back me and a friend went birdwatching on a small island close to home, just a short ferry trip from the mainland. Our goal was a football pitch-sized bog surrounded by high cliffs, very close to civilisation, and yet very remote. This is essentially unchartered ground, as no paths, nor roads, lead into the area, mainly due to the fact that this used to be banned ground for civilians - as the island used to be a military garrison, and at that time stilled banned for foreign nationals. Sadly we didn't see much of anything till close to sunset. On our latitudes, appoximately the same as Churchill, but actually Gothenburg, Sweden, it takes a while to get dark in the evenings, of course. We arrived in the afternoon, hand a nice dinner and waited. In addition to the coastal birds, like gulls and plovers, we saw some song birds, and other small birds, but nothing really exciting. An Euroasian Kestrel (similar to the American Kestrel) worried the smaller birds as he passed, but otherwise things were very calm. A cloud of starlings suddenly appeared and after a lot of false tries settled in a small stand of reeds. Then more starlings arrived in smaller groups, coming from all directions. Evidently these came from neighbouring islands, as this to man fairly unknown bird haven isn't normally frequented by people, cats or dogs. As each subgroup landed the was a bit of commotion, but after a while things settled down - the stand of reeds maybe containing a few thousands starlings, no more than that! Then suddenly, as the sun started to settle, on silent wings, a Short-eared Owl arrived on the scene. Seemed to have its nest in the bog quite close to us, but light was failing fast, so we wasn't too sure if we saw a nest, or not. A rare treat to us city-dwellers, to see this magnificent bird this close - sadly far to dark to take any pictures! Just as the last rays of light hit the cliffs the kestrel reappeared, and he/she didn't like what he saw - an intruder! So suddenly there was a hell of a fight between owl and kestrel, the two eventually crashing into the stand of reeds, and naturally all the starlings took off at once! For a little while the sky was black with panicing starlings, but soon the kestrel gave up - not a very good night flyer, in sharp contrast with the owl, he/she headed home, and the owl returned to its camping ground, to await morning and breakfast, in the form of rodents, or other unwary animals. As day broke, we packed our gear; binoculars, monoculars, MSR stove, et cetera, and took the first morning ferry home, at around 6:00 am. Tord -- Want an e-mail address like mine? Get a free e-mail account today at www.mail.com!
Re: [RCSE] Re: Alternative launch method
Several years ago there was an article in RCM about such a trick. As I remember when the glider released the tow line shot upward into the rotating blades. At that point the helicopter became a glider with a very, very poor L/D. Considering they were several hundred feet up I bet it made a heck of a racket upon return to earth. It is adviceble to drop the line from the chopper first! Or use a weighted line, but then you still have problems during the landing phaze (sp?). So having a release at the helicopter is very wise - a monofilament line, strong enough to held the glider doesn't cost much, so it can be happily discarded, or left hanging behind the glider, as the drag is very, very low! RCSE-List facilities provided by Model Airplane News. Send subscribe and unsubscribe requests to [EMAIL PROTECTED]
[RCSE] Canards-- what a canard!!!
with a tiny, cropped delta, say 4 in span with a small Cox up front, which had the smallest of canards I ever seen, say 3/4 long each side of the very tiny fuselage. These were fully movable, at least +-30 degrees, and slightly swept and quite simple. The elevon-equipped aircraft looped very, very tightly, but only after he added the canard, according to its designer! Now I wish you all a Happy New Year, Tord S Eriksson www.tord.nu RCSE-List facilities provided by Model Airplane News. Send subscribe and unsubscribe requests to [EMAIL PROTECTED] RCSE-List facilities provided by Model Airplane News. Send subscribe and unsubscribe requests to [EMAIL PROTECTED]
[RCSE] Viggen in retrospect
The nose wing on the Viggen works very well at high angles of attack, making it a routine manouvre to land on runways as short as a flight deck of a carrier, using vortex lift and the powerful engine to maximum benefit. Also in turning flight it comes into its own, while flying at low Cls (= high speed) it is more of a hindrance than a boost. At supersonic speed, when the centre of lift is at roughly 50 mean chord, it would be better to have a swing-wing nose wing, that tucks away, like the Milan, an experimental Mirage III variant. Tord S Eriksson www.tord.nu RCSE-List facilities provided by Model Airplane News. Send subscribe and unsubscribe requests to [EMAIL PROTECTED] RCSE-List facilities provided by Model Airplane News. Send subscribe and unsubscribe requests to [EMAIL PROTECTED]
[RCSE] Twin boom
There is certainly an advantage in respect of drag if you use a pusher installation - or a camera plane with a forward-looking camera. Neat, clean and efficient! A world-record holder in endurance that has the FAI record used indeed this arrangement, as does the famous Altantic-crossing Aerosonde! Many rocket planes use it, for sure. If you plan to break speed records think again, as even if the aircraft is flying in undisturned air the propeller isn't! For speed propeller efficiency is very important, for slow endurance, less so! The powered long endurance glider I mentioned above has been sold as a kit called Sunriser, I think - available in Germany, at least! If you plan to use an IC engine you might need to have swept wings to get the CG right, or a lot of lead in the nose! If you plan to build an electric plane with a great folder prop you need to see to that the propeller folds and unfolds correctly, else the motor and prop might get ripped out of the fuselage due to assymetric opening - both blades trying to open up to the same side, with the associated extreme loads. GC is less of a problem as the battery can be stoved in the nose! I love twin-tailed aircraft, but they are not the most efficient around! The Aerosonde needed a pullutant-free nose for their sensors, thus the engine had to go in the rear - had it been possible to use electric I am pretty sure the prop had ended up in the nose! Tord S Eriksson www.tord.nu RCSE-List facilities provided by Model Airplane News. Send subscribe and unsubscribe requests to [EMAIL PROTECTED]
[RCSE] Adding elevator control
Does the design adapt to a full-flying stabilisator? Just mount it slightly above the tailboom on a pivot. If that looks odd mount the wing on a pivot instead! Tord S Eriksson www.tord.nu RCSE-List facilities provided by Model Airplane News. Send subscribe and unsubscribe requests to [EMAIL PROTECTED]
[RCSE] LEDS in the night
Green and yellow are the most visible at night - flashing reds are OK! Much better are electrostatic lights - available from Tim Cone (NightOps) and RC-Neon! Not sure about the addresses ... Tord S Eriksson www.tord.nu RCSE-List facilities provided by Model Airplane News. Send subscribe and unsubscribe requests to [EMAIL PROTECTED]
[RCSE] servos...digital vs analog
The biggest servos I know of are those that keep the modern type of windmill pointing into the wind. They too have problem with deadband logic. To save the motors from constantly adjusting the windmills direction they simply lock up the shaft (by the help of a really big disc brake) till the error between rotor direction and wind becomes too great (there is a time factor, so corrections are not carried out instantly, thus again saving the servo motor. Maybe this could be applied to model airplane servos - mechanical brake locking the surface till the pilot wiggles his sticks? Tord S Eriksson www.tord.nu RCSE-List facilities provided by Model Airplane News. Send subscribe and unsubscribe requests to [EMAIL PROTECTED]
Re: [RCSE] Plane Recommendations
Bill Johns [EMAIL PROTECTED] Wrote: Subject: Re: [RCSE] Plane Recommendations I fly in Missoula, MT. The closest club I can find is about 3.5 - 4 hours away. I fly fairly often (during the warm months), and frequently have people stop to watch. This winter I plan on building a plane that I can use to give the interested watchers a little stick time. With luck I can get enough people to start a club. Get a foamy, consider a Highlander or one of the other of that type. It will build fast (sorry) but will take numerous crashes and still fly well. Use your extra time to build something for yourself that will wet appetites to move up to. I think a foamy will be the best simply because if someone crashes a built-up plane, it will turn to trash and destroy any self-confidence they have and will chase them away form the sport rather than lure them in. Having a forgiving plane that will allow them to make mistakes and laugh about it later is a Good Thing. Built-up planes are pretty and fly well, but they are fragile. I would recommend a powered foamie, say a Zagi 400 or the Twinstar. This way you can launch quickly and they still can get the feel of things! Glide ratio ain't great, but simpler than a glider in this context, unless you have a very good slope at hand! Tord S Eriksson www.tord.nu RCSE-List facilities provided by Model Airplane News. Send subscribe and unsubscribe requests to [EMAIL PROTECTED]
[RCSE] JU-52
Slightly off subject, but the Ju-52 used to tow transport gliders in the Luftwaffe: I am interested in kits or plans for the Ju-52! It should not be the Ju-52/3m, but the single engine version! Any ideas? The FMS simulator gives you a fair feeling of the differences when flying powered (I love the Ju-52/3m) and gliders, but as there is no wind and no thermal activity it isn't like the real thing! Does the CockpitMaster simulator include thermals and winds, by the way? Tord S Eriksson www.tord.nu RCSE-List facilities provided by Model Airplane News. Send subscribe and unsubscribe requests to [EMAIL PROTECTED]
[RCSE] Zagi wins!
Interesting mail from theZagi list - anyone heard of something similar? Tord S Eriksson www.tord.nu === Message: 2 Date: Sun, 27 May 2001 21:50:37 -0700 From: Glen B Elliott [EMAIL PROTECTED] Subject: Zagi versus Light Pole, Zagi Wins!!! I saw one of the most awesome sights today. I was out flying zagis with some friends of mine and one of the guys (Marcus) decided to do some combat with a light pole. We had a nice south wind of about 10mph and he was flying full throttle down wind with a quick 480 in his zagi. He hit the light pole in the center of the right side leading edge. The zagi did a full 360 spin in the air and then hung there and then he just flew it away. The only thing that happened was the front of the canopy was up like the hood of a car and it still kept flying. I wish i had a video camera for that little mishap. He said he did it on purpose to show us how rugged a zagi is. I told him to go ahead and do it again on the left side!! Glen RCSE-List facilities provided by Model Airplane News. Send subscribe and unsubscribe requests to [EMAIL PROTECTED]
[RCSE] Re: Tandem-winged Planes
There are a few issues involved here. The front wing must stall before the main wing, which, in a lowdrag installation often is solved by having wider chord on the rear wing (thus lower AR), usually combined with higher loading on the front wing. The same airfoil can be used, but low pitch airfoils are most likely recommended. According to Boeing research, refered to in one of Darrol Stinton's books, the lowest drag can be had for three-surface aircraft, where manouvering is done with a conventional tail, but trimming is done with the front wing. As the front wing can only be used for pitch adjustments, that is no ailerons or elevons, roll authority might be low. Anhedral on the front wing might be wise, and dihedral on the rear. Often you see sweep on the rear, combined with wing-tip fins. So sweet-stalling front wing, combined with low drag airfoils, should result in a plane with low sink rate as the average wing-loading is lower than a similar conventional plane. Tord S Eriksson www.tord.nu Tord S Eriksson www.tord.nu RCSE-List facilities provided by Model Airplane News. Send subscribe and unsubscribe requests to [EMAIL PROTECTED]
[RCSE] Re: Tandem-winged Planes
- Original Message - From: Tord S Eriksson [EMAIL PROTECTED] To: [EMAIL PROTECTED] Cc: [EMAIL PROTECTED] Sent: Friday, May 18, 2001 7:30 PM Subject: Re: Tandem-winged Planes There are a few issues involved here. The front wing must stall before the main wing, which, in a lowdrag installation often is solved by having wider chord on the rear wing (thus lower AR), usually combined with higher loading on the front wing. The same airfoil can be used, but low pitch airfoils are most likely recommended. According to Boeing research, refered to in one of Darrol Stinton's books, the lowest drag can be had for three-surface aircraft, where manouvering is done with a conventional tail, but trimming is done with the front wing. As the front wing can only be used for pitch adjustments, that is no ailerons or elevons, roll authority might be low. Anhedral on the front wing might be wise, and dihedral on the rear. Often you see sweep on the rear, combined with wing-tip fins. So sweet-stalling front wing, combined with low drag airfoils, should result in a plane with low sink rate as the average wing-loading is lower than a similar conventional plane. Tord S Eriksson www.tord.nu Tord S Eriksson www.tord.nu RCSE-List facilities provided by Model Airplane News. Send subscribe and unsubscribe requests to [EMAIL PROTECTED]
[RCSE] Re: re: re: Right VS Left
The tornado I had the fortune to see very close up (we have them here, too, occasionally) showed very graphically that the flow in the funnel rotated downward in one direction and upward the other! Tord S Eriksson www.tord.nu RCSE-List facilities provided by Model Airplane News. Send subscribe and unsubscribe requests to [EMAIL PROTECTED]
[RCSE] RE: How to improve ...
Well, first and foremost I would think the CG is a bit too far back for your ability. You need more forward CG for relaxed un-powered flight. The prop stalled will act less as a fin than when rotating - if you fly your plane propeller-less the differencies are even bigger. One thing you could try is to slope it motorless, as that moves the CG forward quite a bit! You need to retrim the elevons, too, of course! The can guess reason the elevons look like they do is that the designer (hi Jerry!) wanted most of the control surface near the tips for optimum rolling and elevator power. As wing thickness and width, CG and inertia factors also affect the design, you don't want thick, heavy servos at the tips, where they probably would be more effective! On swept-wing jet aircraft ailerons and elevons often taper in width towards the wing tip, as the one thing that true high-speed design must avoid is flutter. The hydraulic ram, operating the surface, sits near the inner end, where the width of the control surface is widest, thus stiffest. Usually the ram power and movement limits are varied with speed, as the controls become stiffer to move with speed and less efficient! Sometimes there are two sets of ailerons, where the outer is only used at low speed, as to avoid flutter problems. If the control surface's width, compared to the wing's, increases in percent as we go towards the tip, as on a Zagi, the wing rolls more efficiently than one where the width (in percent) decreases toward the tip. Gliders (full-size) of the 50's often had ailerons that disappeared to nothing towards the tip, spelling out two facts: torsional stiffness of the wing nor the aileron wasn't that good, and the aircraft were no aerobatic masters! On a flying wing these problems are further accentuated! At the same time most wings will not stand a maximum control surface movement at high subsonic speed (efficiency drops off over Mach 1), so most likely slower movements but more. If unpowered the limits are set by the pilot's strength, if powered a limiter is often incorporated. The Zagi - hardly transsonic - solves this with VERY flexible elevons - at low speed the outer ends move all the way, while at high speed the airloads bend the surfaces to an amazing degree! Thus a force limiter built-in! Thus there is less risk for overloading, if built as designed. Build stiffer elevons and you might need to beef up all the other parts too, change to more expensive servos, install more spars and reinforcements, et cetera! Often just changing motor to something slightly more powerful leads to other changes - as the structure proves to be too weak for the increased loads and speeds, or the plane look decidedly haggard after a short while! Or you end up with a molded Zagi, with CF elevons, that will stand a lot before it breaks to pieces. But it is then another kind of aircraft! And not according to the Slope Combat rules! Tord S Eriksson www.tord.nu RCSE-List facilities provided by Model Airplane News. Send subscribe and unsubscribe requests to [EMAIL PROTECTED]
[RCSE] Re: Alfa4 and If I owned a small business....
I used to own a small business, that eventually failed, so I might qualify: You look for a product to sell (retail or otherwise) that brings in good profits, ideally for little input. Classic success stories are hot dog stands, classic failures are small bookshops and model shops! Glassed gliders are to me a bad choice of product as any irregularity is easily seen, while foamies are excellent, as the latter kits are relatively easy to make (cheap infrastucture), there is no supplied surface that even a nim-com-poop can critizise. Make a good model through good prototyping, turn it into a simple, sturdy kit and then add a good manual and your in the money, I am sure. Great Planes are typical, as is Daves Aircraft Works. The road to success for glassed gliders, like the Muller range, is so much longer and the investment so much bigger. The gamble is higher, and the prices has to likewise be higher! If it fails it fails terribly, if a foamie kit manufacturer fails, like BASH, we hardly notice! Moulded kits is even more dangerous! So if you find a product, whether aircraft kit or charger, that is simple to make (gives reasonable profits) and that is in high demand due to their good characteristics I would stick to that. If I expanded I'd loose quality control and customer input - I personally would hate that! Maule seems to have gotten those figures right, as did Mr Pitts for a number of years, if we look into full-size aircraft. WACO disappeared, and many other makes of glassed gliders, persumably from too small profit margins - or having earnings elsewhere that overshadowed the joys and despairs of company ownership and production! Even among EPP kit makers there are survivors and dropouts, even if the breakeven point must be far lower EPPs than for moulded kits! Yours, Tord S Eriksson www.tord.nu PS Just inspected my latest DAW kit - awsome! RCSE-List facilities provided by Model Airplane News. Send "subscribe" and "unsubscribe" requests to [EMAIL PROTECTED]
