Design > Stunt design
Another odd question - Forward sept wing trailing edge and flap hinge line
M Spencer:
Published The ories ! . Hunt / Wewage - > Effectivly LONGER MOMENT ARM . if you average the hinge , half way out , its further forward .
P. Walker . - . " Break my arm if you ever see me try another swept forward hinge ! " yaw / Trim instabilty ' errors ' making it a P A I N .
My ' observations , having half the planes with it , most severe sweep . Like THIS , ( Which is a M B 5 minus two . First 5 had that empenage , so a 3 could have 5 tail feathers , if you wanted to make life easier .)
o.k. Had a wreck 65 ounce STANDARD F2B ' 46 / 60 ' ( magnum based ) dunger out in hard bumpy air on the weekeend .
Had me thinking Id have to do a Standard ' 46 / 60 ' DECENT Genisis Spectrum Hallmark STANDARD YANKEE STUNT SHIP . as the orrible free T Tiger 46 ona 12 x 6 Tornado without touching the needle ' Did the Trick '
if not perfectly , PERHAPS it'll be acceptabilitil . as theres another two came withiit need bearings , it'll be three free . As We Said ' Something your not to worried about PLANTING ' ( in a GALE - . so no undred hourfinish or suchlike )
Swept Hinge - Stability - YAW . and THINGS .
published ' Hunt werwage ' = " Self Servo Effect " as in lighter control loads with it . IN THE WIND .
Bob ' quote ' Genisis 3 favourite ' with the is it ? 3/4 Flap Hinge Sweep .
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THIS with a Rabe Mustang FIVE Airfoil . Fully sheeted . SEE THE HINGE LINE . Mate . H^^
For Flying in GALES - Rough air - Turbulance . a projectile . , 4.5 to 4.8 if your lucky , lap time . Std. Setting it usually self ' unloaded ' to suit on Atd. setting . THOUGH , when its billowing like billyoooooo
o , Down Proping keeps it moving . or accelerating ' out of a hole ' . With Tourque ( reactive force ) being the PRIME ISSUE . aaarrggghhhhh . Duck . Wheres my helmet . So there are limits .
HOWEVER : That Scale planform , once at 2:3 Flap to elevator , flew itself through the pattern smoothly , consistantly , and self generated consistant ' bottoms' Tho the V 8 from inverted , downward -
required ' comitment ' . After seeing it do it o.k. a few times , one accepted it was possaable . If inexplicable .
WITH THE 1/8 " FLAP HORN WIRE & C/F PUSHROD . Stiff 1/2 flaps and elevator . AND the prime flying feedback was the wee tail followed . the WING lifting the ship , in the rounds . In the squares ,
It was ' On the Controls ' ( as in the moving surfaces seemed the primary element - in force . other than the POWER . Equal and in concert . Apparently . )
That , A few spitfires , a Mustang , and others , WITH DIHEADRAL = The YAW is the complication . MB3 was fine - other than into the clover ( 45 up level ) and Top - 2nd Crner in the Hourglass .
this is where being able to leap 30 foot per bound saved the day .
AS IT NEVER HIT THE GROUND , the obsevation was a Rabe rudder may've made the jackrabbit act unnessesary .
Wot appens with diheadral & swept hinges ; The Yaw ( resultant of POWER reaction . ' prop grab ' - plane try to rotate opposite prop . As the PRIOP's ' gripped ' and the plane ' HASNT GOT A HOLD / Grip . ->
it's in a AIR HOLE OR UNBALANCED . The reaction to the primary force ( power - at that point , engine ON . )
The Flat Wing rather swept Folkerts , concived around 76 , for a 11 x 4 ! ! , If it KEPT MOVING was pretty good regarding yaw , roll , tension , and things like that .
First Flight on 9 mm intake 7 C'case pressure - Hor. Eights high , upwind , were FINE .
So presumeably electrification would lower the fuel consumtion to acceptabe . for that trim .
Presumeably , deflected swept flaps ' gather ' the atmosphere inwardly , in extremis , the fuselage acts as a fence , so working hard at high pressure , the flow theres good.
In V light wind and over 15 , the Folk was ' neutral ' fore & aft . around 8 to 12 it was soggeyer , wanting a touch more flap dialed in .
So , a SUMMARY . Adjustable Ratio . fore & aft . Provision for interconnected rudder , for if required . 1/8 wire flap horn wire for .46 / 60 . Im thinking the 5/32 is a bit stiff for bumpy air , when its blowing .
Several Notorious champions consider a little cushioning in roll from air load deflection is neccesary . the lenght of arm along the hinge , as a torsion bar , absorbs some ' bump ' reducing roll in uneven air turbulance .
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M Spencer:
" Knocking you down would take a wind of at least 70 mph. The terminal velocity, which is the wind speed (falling speed) where the force of the wind equals the force of gravity, for a person is about 120 mph — that would likely knock you down. "
Figured a 1.2 lap time with G 15 on 50's is 187 / 300 kph odd . From the shelter of a Big hedge , a calm day oon a cyclone ( Hurricane ) the air from the Tasman concentrating falling across Auckland Harbour.
Raising on the raise and dropping to funnel through out downwind , the pushing down on the ground air from the raise over the Macracapra Hedge further enhancing its efficency , Sothat on occassion , downwind
the pip was sqyuezzed from the 180 downwind to say 240 / 250 , where it was inobservable . QUICK , befor the noise stopped twice as it hit ' into wind ' concurrent with a judder or two , before into the lee of the
hedge .
So , theres wind and theres wind . Three Goes totalling the field got it back after trying loops in lulls ! ? on the next flight , without breaking the lines . The new .015 solids woulda snapped like spagetti , if you ' caught '
it firm without cushioning the snatch .The brother refused to launch it for a third go . And I was just getting the hang of it ! . S?P
Now this deflector ! ( NOTE THE DEFLECTION ) was a Renouned Wind Flyer . So we presume he knew a thing or two about it . He mayve even have thought aboutit a bit . and come to a few concusions .
LIKE THIS .
He perhaps mayve decided , was the way to doit .
My sealevel speriance gotme looking athis . Thought the inge might even keepit stright , inna urricane but wotid I know . I was only 16 . Nontheless . It was Contrived for a 11 x 4 prop & 40 knot wind . wotyer got often . for a HP or torp 40 rear induction . or a Super tigre maybe . R V .
THIS didnt like a muffler inboard ( it'd kick - drop nose to zero tension , on a slow wingover , 2/3rd thu. ( or 60 up, dowhill ) a step & kick appropriate line , and it'd ' caught ' the air again ! ! .
(( I wondered ; and figured . Maybe it was the equal Taper wing . Smaller Chord inboard tip . The Later bl %^@dy gret big one with the ribs the same, and tips. Dont do that . So USE EQUAL TIPS . )
muffler outboard itdidnt doit . or muffler free . With a 9 mm intake on a 21/40 ST & C'case pressure , unmuffled . it didnt even think of it . Was fine manouvreing UPWIND . But used a bit of juice .
So THATS Swept Flap Hinges . Digest in morsels r youll get indegestion . See you dont choke . SET A FEW PARRAMETERS and ARRANGE THE REST to SUIT . theres no ' one sixze fits all ' .
The throw the componnents on the floor & get a bit of chalk , got Coppers a few World Championships . . F1 Grand Prix . BALNCE & PROPORTION is whereitsat . Mate .
A Genisis Three with a funny fuselage , and Bob's your Uncle . S?P ( Hunt swept Hinge . hope bob chimes in with his observations , Has Flown Bill's Juno , too. I think . )
To the Field once or twice , down the sheltered street , the sprint across the main road in a lull , and across the gap to the lee behind the 12 foot hedge , crouched sprinting holding tight with all fingers & toes
did the trick .
I believe it was some time before someone got a 300 kph lap out of a .15 on straight fuel .
THUS : a few comments regards ' flying in the wind ' have some grounds in fact .
Power , Yaw control . ( Balanced Fuse. Side Area . ) I find with a flat wing , C G & leadouts at near the bellcrank pivot , the reliable waytago . One can even ease the C G Behind the pivot .
A ROUNDED ( fully ) fuse is less implicated in the cross wind effect . To big a rudder or nose , will act as a vane or suchlike .
As In lowish Fuse side Area , and not a oversized rudder , will get it stable in yaw , for a flat wing .
Diheadral your better having it 5 ton And good stiff flaps , Elevators & controls . Like a 2 kilo 630 Sq. in. M B 3 . and wear a helmet . Obviously 18 thou. lines are a minimum , billowing over 18 Knot wind .
FLAP SWEEP . if its got a TON put a RABE RUDDEr onit . while yer buildingit .
Bill Schluckbier:
Bob - Thank you so much for taking the time to post a reply. I really enjoy reading the history of how the design choices came about; it provides them with context.
Thank you,
Bill
doug coursey:
HERES A VIDEO OF WINDYS SPITFIRE WITH SWEPT TRAILING EDGES
Steve Helmick:
When asked about that (swept forward flap hingeline), Paul Walker said it made trimming MUCH more difficult.
I'd leave it at that, but considering that a lot of models are flown for years and still aren't really well trimmed, it makes sense to just don't do it. H^^ Steve
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