RE: Predator have flaps ?
yes it has flaps... actually... two flaps per side.... and two ailerons per side.... the whole wing trailing edge is used to optimize the camber to the flight condition... how do I know??? I did the layout and design of the majority of the wing!! ;)
Posted on: 9/9/2012 11:37 PM by Author "mithrandir" in the forum "FPV, UAV''s & Drones"
http://www.rcuniverse.com/forum/fb.asp?m=11223393

RE: Wing type question
"Stability" is the characteristic of a dynamic system to return to equilibrium after an external force disturbs it... no? How does a constant cord wing restore a plane to level flight? or even restore the wings to level? (No sideslip) I don't see how spanwise flow has any stabilizing tendencies? The reasons for taper are to more efficiently achieve an eliptical lift distribution. A rectangular planform still has a mostly eliptical distribution , barring unusual twist or airfoil distributions.... the true benefit of the tapered wing is the reduced drag. (Reduced wetted area) For a given or fixed area, a tapered wing yields a larger root cord.. thusly a thicker wing at the root... better for reacting the bending moment... in the context of this thread and most aerobatic RC Models, Extras, Yaks, Edges etc, the typical AR is in the 5:1 to 6:1 range...... a tapered wing will simply fly more precisely and roll, snap and spin "Better".... Turbulance does not cause roll excursions as bad.... in the context of 3D models, the low taper and no-taper planes I have flown seemed to suffer harrier performance.... I estimate, the smaller wing tips of a tapered wing stall easier, and stay stalled.. so the wing-wallow'ing doesn't occur as does every constant cord wing'd plane I have flown..... I think sweep can improve this situation.. my AW 42% Ultimate Biplane was a harrier trainer!
Posted on: 8/15/2012 11:54 AM by Author "mithrandir" in the forum "Aerodynamics"
http://www.rcuniverse.com/forum/fb.asp?m=11194576

RE: Wing type question
IMHO, the constant cord wing will be a little bit of a pig. It will not snap as cleanly, nor spin, it will not roll as quickly or cleanly. It will as mentioned above have more benign stall qualities... (Thusly the poor snap/spin performance) The wing loading will be lower... so landings can be slower.. and having big tips, it isn't prone to sudden tip stalls.... if the taper ratio isn't extreme, and the airfoil selection is good... the tapered wing will overall fly better... if you want a plane that tracks and flies precisely, the tapered wing is the wing of choice... if you want a plane to 3D.. the tapered wing is the correct choice.... at 78 inches... 12 pounds is not horrible (assuming a 5.5:1'ish AR) I am unsure how a constant cord is "More Stable"... as I don't see any qualities of a planform that will restore a planes flight path to level... or level wings... perhaps RMH meant "Higher Damping"... if built light, it could have higher damping.... if you are a pretty hot-shot pilot... go for the tapered wing..... this is a 7 year old vid of an electric 2 meter Katana with a 10S x 8000 mah LiPo at 12.5 pounds.... http://www.giantcircus.com/Videos/FUNTANA140S.wmv very benign flying plane... even with the tapered wing....
Posted on: 8/14/2012 5:37 PM by Author "mithrandir" in the forum "Aerodynamics"
http://www.rcuniverse.com/forum/fb.asp?m=11193659

RE: Coupling question
how far aft is "Aft"? (To the neutral pitch stability point or further) What is the reason for downthrust?
Posted on: 6/5/2012 1:43 PM by Author "mithrandir" in the forum "RC Pattern Flying"
http://www.rcuniverse.com/forum/fb.asp?m=11107624

RE: Coupling question
first... do an upline with power and bang the rudder.... see if it does what you describe.... (Do seperate upline verticals testing left rudder and then right rudder) then.... try doing a downline at idle power and see if the phenomonon still exists... if it does this on an upline with power, but not on a downline without power.. prolly it is a prop/P-Factor dealy-bob.. otherwise something else going on....
Posted on: 6/4/2012 11:12 PM by Author "mithrandir" in the forum "RC Pattern Flying"
http://www.rcuniverse.com/forum/fb.asp?m=11106892

RE: 1st Annual Bakersfield D7 Spring Pattern Bash
If I still had this... I woulda showed up!! lol http://www.giantcircus.com/Daddy_02/herman315.htm http://www.giantcircus.com/Daddy_02/herman314.htm looks like yuh'all had a lot of fun....
Posted on: 4/30/2012 4:36 PM by Author "mithrandir" in the forum "RC Pattern Flying"
http://www.rcuniverse.com/forum/fb.asp?m=11063169

RE: What are these little fences for?
the fences can never be truly aligned with the flow.... the flow has a spanwise component that changes as the wing AOA changes... so there is always a little vorticity shedding from these little guys.... though the effectiveness of the control surface might be improved, it is not without penalty...Prolly a net loss on a racer....
Posted on: 4/19/2012 3:19 PM by Author "mithrandir" in the forum "Aerodynamics"
http://www.rcuniverse.com/forum/fb.asp?m=11048976

RE: 1st Annual Bakersfield D7 Spring Pattern Bash
[quote]ORIGINAL: Passport1 ............ I am seriously thinking this may turn into an event that will be here for many years to come. ................Maybe we should call this the Bear Mountain Spring Nationals or something to that affect in the future. C [/quote] Spring Pattern Festival!
Posted on: 4/19/2012 3:06 PM by Author "mithrandir" in the forum "RC Pattern Flying"
http://www.rcuniverse.com/forum/fb.asp?m=11048960

RE: 1st Annual Bakersfield D7 Spring Pattern Bash
so first it was 2 guys flying one plane..... ... now... one guy flying two planes..... ....... I am 'fraid to ask what is next!! lol
Posted on: 4/3/2012 5:36 PM by Author "mithrandir" in the forum "RC Pattern Flying"
http://www.rcuniverse.com/forum/fb.asp?m=11027266

RE: DIST 7, VICTORVILLE VALLEY RC FLYER, 2nd ANNUAL PATTERN CONTEST
Awe rats... I wanted to Meet Jerry Budd!!! Maybe if I get my ESC back, I can practice again and catch him at the next one??? mds
Posted on: 4/2/2012 2:46 PM by Author "mithrandir" in the forum "RC Pattern Flying"
http://www.rcuniverse.com/forum/fb.asp?m=11025532

RE: DIST 7, VICTORVILLE VALLEY RC FLYER, 2nd ANNUAL PATTERN CONTEST
Did it happen saturday?
Posted on: 4/1/2012 7:56 AM by Author "mithrandir" in the forum "RC Pattern Flying"
http://www.rcuniverse.com/forum/fb.asp?m=11023558

RE: DIST 7, VICTORVILLE VALLEY RC FLYER, 2nd ANNUAL PATTERN CONTEST
Nice... I was wondering what was up with this as I haven't read too much about it.... Our site has an awesome paved runway!! and plenty-o-shade and pit area!!
Posted on: 3/29/2012 9:55 AM by Author "mithrandir" in the forum "RC Pattern Flying"
http://www.rcuniverse.com/forum/fb.asp?m=11019931

RE: How much tail wheel weight?
[quote]ORIGINAL: rmh FWIW- I just setup a 1/5 scale Mustang -using a DX8 radio and two rudder servos - one for the rudder - one for the tailwheel- The TX allows for mixing in the relative amount of deflection and the relative center position of the tailwheel. great setup. I have found thru much trial and error - that models such as this need very little wheel movement (relative to rudder movement) and the power on tracking CENTER needs real times experimenting to get best straight on tracking As example -set tailwheel LEFT a bit and hold in a little right rudder . Typically you will be holding in right rudder as roll speed increases and too much tailwheel movement simply screws up the tracking. [/quote] Seems this is further complicated as the tailwheel of the P-51 is set further fwd making it rather short coupled as well!! I have heard of some of the guys flying the narrow main's BF109 and Spitfires using a gyro on the tailwheel.... maybe not a bad solution?
Posted on: 3/29/2012 9:53 AM by Author "mithrandir" in the forum "Aerodynamics"
http://www.rcuniverse.com/forum/fb.asp?m=11019930

RE: Power Glider Airfoil
http://www.ae.illinois.edu/m-selig/ads/coord_database.html the selig 7037 is a nice floater section.. the RG15 is a nice go'er section...
Posted on: 3/26/2012 11:25 AM by Author "mithrandir" in the forum "Aerodynamics"
http://www.rcuniverse.com/forum/fb.asp?m=11015780

RE: How much tail wheel weight?
it is customary with taildraggers to hold up elevator, sticking the tailwheel to the ground until there is enuff airspeed for the rudder to provide steering.... ever notice how often people taxi with the elevator full backstick? [i]"a noseover is natures way of preventing larger problems"[/i] nice.. I will remember that!!! lol
Posted on: 3/26/2012 11:17 AM by Author "mithrandir" in the forum "Aerodynamics"
http://www.rcuniverse.com/forum/fb.asp?m=11015771

RE: RE:
the aft spar serves the purpose of creating a closed wing structure for torsional stiffness.... it is necessary... don't leave it out...
Posted on: 3/26/2012 11:12 AM by Author "mithrandir" in the forum "Aerodynamics"
http://www.rcuniverse.com/forum/fb.asp?m=11015762

RE: BJCraft Episode
[quote]ORIGINAL: Doug Cronkhite SFGs are intended to provide more yaw lifting force I'd guess. The problem I see is that it isn't free. You lose yaw stability because of the proximity to the aerodynamic center of the airplane. Today's fuselages are big enough that I just don't see a need for the SFGs in the sizes most people are using. In order to get any real effective use out of the SFGs they'd have to be MUCH larger. [/quote] The SFG's do limit the spanwise flow over the tip of the aileron so increased aileron effectiveness can result.... but as you say... there is a price to pay.....
Posted on: 3/20/2012 3:15 PM by Author "mithrandir" in the forum "Electric Pattern Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=11008694

RE: Great Planes F-86 Sabre Micro EDF
nice vids!!
Posted on: 3/12/2012 11:30 AM by Author "mithrandir" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=10997145

RE: 2012 Kettering University Aero Design Plane
conventional designs prevail for a reason.... ... they perform better.... Tandem configuration suffers more drag for the lift generated... ... what drove you to this?
Posted on: 2/28/2012 10:02 AM by Author "mithrandir" in the forum "Aerodynamics"
http://www.rcuniverse.com/forum/fb.asp?m=10980064

RE: Knife edge tucking
[quote]ORIGINAL: tomfiorentino [quote]ORIGINAL: rmh 99% of the time - the cg location causes this to happen. the reason is that the wing is not working against gravity in knife edge - so the ''trims'' which cause a perfectly balanced hands off level flight, now become apparant. [/quote] Hey Dick listen, I know this thread was a while ago (so I hope you see this post!) but I have a quick question for you regarding a CG change and slaving elevator to rudder to fix KE flight. I understand your quote above and have in fact experienced it with a Tiger 60 I flew the covering off of....twice! [:D]. So when the wing is not working against gravity in KE the trims from hands off level flight become apparent. Great. Why then, are the mixes used to fix it in KE flight still relevant in level flight as well...when the wing is working against gravity? For example, if I remove the down elevator trim through a mix with rudder input to prevent tucking in knife, why might I still need that mix to remove down elevator trim with rudder input in straight and level to prevent a dive with rudder input. The wing forces are very different relative to gravity, but the mix is the same. Dumb question...what am I missing? Thank you, Tom [/quote] Great Question! The answer is because the stab height matters.... Try a rudder input from inverted with the mix off.... try it on a down line..... I challenge Dick to take his plane out and do the flight test maneuvers I have suggested.... particularly.... the pull to 45 degree test..... I challenge him to pull his trimmed plane to a 45 degree line, roll to Knife Edge and let go of the sticks.... (If his plane isn't super-nose-heavy).. it should basically follow a trajectory and pull slightly to the canopy..... now Dick... repeat and apply rudder.... guess what... it pitches! (Unless you have a model that happens to have the stab in the correct location) Repeat this on down lines.... on a vertical downline, most nicely trimmed models will slightly pull to canopy..... apply rudder.... pitch to gear.... This is fairly typical and I challenge yuh'all to try this and see what happens.... (A model that has significant dihedral or a high wing like a cub may be difficult to observe some of this phenomena as there will be significant roll coupling to the rudder) But with a Yak, Edge, Extra, Su etc... this can be seen and repeated....
Posted on: 2/28/2012 9:34 AM by Author "mithrandir" in the forum "Aerodynamics"
http://www.rcuniverse.com/forum/fb.asp?m=10980025

RE: Great Planes F-86 Sabre Micro EDF
[quote]ORIGINAL: wind junkie This plane is super tiny. Its unrealistic to expect that sort of speed from a battery the size of a peanut for any sustainined period. Plus nobody can see a plane that small if it gets too fast. Best to keep it slow and ''floaty'' as possible or nobody (else) will want to buy one. There are plenty of small fast jets out there. This strikes me as more of a novelty and should not be a good candidate for hop up mods. Just seeing a Sabre in the air this small and ''cute'' is reason enough to make most aviation aficionados smile. [/quote] I agree 100% At this size... 30 mph is enuff.... if you let it go straight for more than a few seconds.. it will be hard to see.... Fortunately, the jet was designed such that you can "Bank'n'Yank" fairly aggressively [b]without[/b] Tippy-Rock qualities.... and.. it will actually fly around nicely at fractional power settings... When one thinks of a foamie, 15 inch EDF, one doesn't initially have high expectations.... I guess that is part of what makes this jet fun.,.... you don't expect it to perform well.... and then it actually does!! lol at least... that is what I remember'd before my son took it from me!!! ;)
Posted on: 2/27/2012 9:56 AM by Author "mithrandir" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=10978374

RE: Great Planes F-86 Sabre Micro EDF
I was at work today... looking out the window at the calm winds.... my son calls me and says "I flew MY jet at the park today Daddy" nice...... that made me feel just great! [X(]
Posted on: 2/21/2012 5:00 PM by Author "mithrandir" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=10969864

RE: Great Planes F-86 Sabre Micro EDF
Awe CRAP!!! I LOST my F-86 Saturday!!!!! TOTAL Loss!!! My son flew it and decided it is his..... ..... I haven't flown it since!! he has 6 more flights on it....
Posted on: 2/20/2012 8:40 PM by Author "mithrandir" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=10968546

RE: Pattern or IMAC
In my humble and unimportant opinion, IMAC is handcuffed by the archaic notion that their planes ought to only be doing the maneuvers that real IAC planes do..... this was a founding concept of the genre.... but RC has sooooo outpaced full size planes.... IMHO... that rigid constraint ought to be eliminated..... the sequence of maneuvers ought to include whatever an RC plane can do .... example... Rolling Loops.... 1 1/2 snaps from KE to KE..... not to mention judging criteria could be established for most of the "3D" maneuvers..... I will tip my hat to the pattern guys... they have more difficult and interesting sequences.... they don't seem to rely upon more and more snaps as a means to distinguish the different classes.... boy.. I am gonna catch heat over this!! lol
Posted on: 2/16/2012 4:10 PM by Author "mithrandir" in the forum "RC Pattern Flying"
http://www.rcuniverse.com/forum/fb.asp?m=10962217

RE: aerobatic full scale airfoil
as an absolute scale plane.. it will fly nice.... it will not fly 3D nor IMAC nice.... the scale airfoil will prolly be very benign... prolly a bit draggy.... but it won't be a tippy rock.... I would say the scale airfoil is a bit like some of the RC Fun-Fly planes.....
Posted on: 2/16/2012 4:01 PM by Author "mithrandir" in the forum "IMAC"
http://www.rcuniverse.com/forum/fb.asp?m=10962203

RE: Great Planes F-86 Sabre Micro EDF
I am gonna say that the Rx and the ANY-LINK Module were linked at the factory. When I bought my first FASST Rx and Tx module.... they were in seperate boxes.. but already linked to eachother.... I didn't need to Link'em... so I didn't even search the Rx for the Link Button!! lol I dunno if I coulda found it anyway.... that thing is tiny!!! he he he he [quote]ORIGINAL: Greg Covey Thanks for the report! Cute first photo...it sure looks like your son took ownership of the micro F-86! :) I like the idea of being able to use any old transmitter. The AnyLink appears to be a versatile solution. My instruction book talked about ''binding'' the AnyLink to the receiver using a button on the receiver. I did not find any button on my receiver in the F-86 and my AnyLink seemed to auto-bind on the first power up. What was your experience here? [/quote]
Posted on: 2/16/2012 8:02 AM by Author "mithrandir" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=10961561

RE: Great Planes F-86 Sabre Micro EDF
[size=3]Here is a quick shot of HOBBICO's answer to the "B'n'F" that has been offered by Horizon.... http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXBPKF&P=V The cost is twenty bucks, but it makes any of the popular Tactic Equipped ARF/RTF's a "Link'n'Load" with any manufacturers Transmitter!!! Simply use the supplied cables to plug into the trainer port and secure the module to the back of the transmitter!!! Velcro-Zilla included[/size]
Posted on: 2/16/2012 12:38 AM by Author "mithrandir" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=10961239

RE: Great Planes F-86 Sabre Micro EDF
[size=3] This is the kinda plane I would like to leave under the desk at my office... So.. seeing as how I prolly don't wanna leave my 14MZ there all the time... (and then I gotta r'member to bring it home on friday for the weekend!!).. I thought maybe I could put that old 72 mhz 6 channel to good use!!! So I blew the dust off it and created a new model.... Plugged in the ANY-LINK Module. Turned it on and Bingo!! We had a love connection!! You can see the solid red light on the Rx.. this indicates the Rx is link'd with the ANY-LINK module plugged into the Tx! Here we are.. Ready to FLY!!! (Ugh... We had snow and hail today with 35 mph winds!!! ) And the Green light on the ANY-LINK module indicates everything is as it should be!!!! I will get some flight video this weekend if winter takes a break and lets the wind calm down!!! [/size]
Posted on: 2/16/2012 12:07 AM by Author "mithrandir" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=10961244

RE: Great Planes F-86 Sabre Micro EDF
[size=3] A picture looking down the barrel.... they did a nice job making a clean and continuous duct from the inlet, through the 35mm fan all the way to the tail pipe![/size]
Posted on: 2/16/2012 12:03 AM by Author "mithrandir" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=10961240

RE: Great Planes F-86 Sabre Micro EDF
[size=3] I received a box unexpectedly at work tuesday. Hmmmm... what is this???? I pop it open ... Shazzam!!! What a freakin' awesomely cute little Jet from Great Planes! I don't want to call it small or "Micro"... I am gonna call it "Fun Sized"!! RTF weight is what... Under 3 Ounces!! I don't even have it out of the box and my 2 year old son figures it is the perfect scale for him!![/size]
Posted on: 2/16/2012 12:00 AM by Author "mithrandir" in the forum "Electric RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=10961235