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Author Topic: Brodak Oriental  (Read 3967 times)

Offline Chuck_Smith

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Brodak Oriental
« on: November 28, 2024, 08:54:54 AM »
Several years ago I decided to build a Brodak Oriental profile for fun. Brodak sent me the built up-fuse kit and when I called them they told me if I wanted I could keep it at the profile price. Done! 

I still very much enjoy flying the old-school OS .35/uniflow setup on a 4-2-4 I grew up with when I get the chance.  The kit was pretty nice and yielded a straight, light airframe. I flew this plane for many years and let's just say it was always - quirky. Turns good, grooves in level but squares have always been an adventure. No amount of trimming would remove the wobble. Leadouts. tip weight, flap mix, nothing. Even tried heavier lines once to see what that would do. (And to those who weren't around in the day, the old .35 ships were generally delightful to fly. Groovy and a "power steering" feel to the light controls.)

I ran into a skilled flying buddy who was flying one too and he had exactly the same experience. Now, given it's basically constant chord with a high aspect ratio I'm not expecting a great windy day ship, but it's just - haunted. We've all ran into one of these during our controline career. But the fact that another good pilot/builder had one doing EXACTLY what mine was doing pointed to a design issue.

A couple month ago, flying it on a day WAY to windy for it - it wound up on a square, I had to really whack the last corner and it go so squirrely it bounced. Yep, pilot error got me in a bad place and then the ship wouldn't bail me out. The plane was so old it broke the motor mounts that were pretty fuel compromised.

having grown up doing this hobby on a paperboy's salary I have this ingrained notion that nothing gets thrown away. Wing was still in super shape so I built a new profile out out it.  Had to move the bellcrank mount but nothing major.

Flying it still has the Oriental Haunted Squares. Not losing speed, nowhere near a stall, it just goes into a really unpredictable yaw oscillation. We first thought it was the original Oriental fuse config being so low in side area, especially up front. To combat this, my profile fuse had a very "Goldberg" look with a lot of cross section ahead to the wing high point. But that had no real effect.



Sitting back and looking at everything, the constant is the wing. Looking at the Brodak kit wing, one thing becomes obvious: the inboard wing is considerably longer than the outboard. More than is usually found on designs of it's day and certainly more than in vogue these days. I'm beginning to wonder if the induced drag during squares on the super elongated inboard wing is the culprit. The ship pulls the wing back on squares ( both ways). Tip weight is dead-on for hinging, the issue is yaw and not roll and I've done a lot of changes from zero to extreme amounts of tip weight and they didn't stop the issue.

I have plenty of fine flying models but this one really interests me. Most engineering breakthroughs start with "That's wierd!" Just in case anyone asks, this is called the "ODP" which stands for Oriental Derived Profile." Modernized by shortening the nose slightly and increasing horizontal tail area.

Anyone else have experience with the Brodak Oriental kit?

We now return you to .60 sized ships that make the pattern a breeze.


More to follow.

Chuck

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Offline Shorts,David

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Re: Brodak Oriental
« Reply #1 on: December 02, 2024, 04:41:59 PM »
I used brodak ribs and brodak plans on mine.  It hunted on electric power but flew fine on ic. Maneuvers were fine other than the hunting.
I have a brodak Oriental wing lying around I plan on building a plane around someday.  I assume it will fly great...

Offline Air Ministry

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Re: Brodak Oriental
« Reply #2 on: December 03, 2024, 09:41:58 PM »
synopsis or yaw'n Orientals .  >:(   8)

Them Theres Hoareyentals , Moit .



PROFILE   , Even .  with the assymetry . Stand By for conbobulation .

You can SEE the Leadouts There , Id Guess '; as per plan ' . The one in themiddle I use airfoil; pulled in one inch aft , more curve there therefore . ( 7 inch chord ).
Just bin givin a set of TWISTER ribs , woter thicker . Nearer two than one an a alff . but 8 inch chord by 48 inch span . As per our marvelous uvers , Shown . Mate .

I THINK ITS YOUR BELLCRANK / PUSHROD / HORNS , more'n anyfing . peraps . Or the softness of the flaps , perhaps .
one visualises & pontificates on AIR LOADS . Hangs it from the leadouts ( to the rafter ) pull like blazes . If your lucky it hits your foot , when you pull the nail out .
Easier with three arms , a second bod. O.K. , Fair Pull , finger / thumb . wobble - L Flap , R Flap . BOTH . Flap to flap - wobble . Elevator side to side - wobble .
ELEVATOR ALIGNMENT IS CRUCIAL == It'll ROLL ( Yaw ?? ) and olther  things . AND check Flap TO Elevator wotsit - security - stability - As I think THERE is what gets you .

As these things have GUIDES ( on the PUSHROD - one or two )  3 / 32 wire home made control horns . The longer the cross piece the more wobble , & weight .

THE BOG STOCK ORIENTAL WING & TAIL AREAS : illustrated . No Yaw in that. Mate .  See last summery . It is the least of them in THAT . There .  H^^


« Last Edit: December 03, 2024, 10:49:12 PM by Scientifiction . »

Offline Air Ministry

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Re: Brodak Oriental
« Reply #3 on: December 03, 2024, 10:13:16 PM »
Now , if one were talking about SIDE AREA DISTRIBUTION , like what you were , youd see it has a bit .
The Ginormous 58 inch Gloster Meteor  had MORE , Considerably . So 15 thou sig lines stretched 20 foot .
 ;D Which gave 1/4 loop del;ay in a eight , which was ' intresting ' . These FLY on .015 / .016 solis ,
or .018 Laystrate ( 7 strand STEEL ) 60's a bit short , 65's pretty good , 70 on the beeg varn is velly good,
INDEED . with FP 25s on 9 x 4 's . DEADLY  ACCURATE . No Bounce , No Bobble , No Trouble . steady Tension .

No Yaw . But then its got a thousand foot of SIDE AREA . Seing youm mentioned it .
The rignil 74 430 ounce OS max .20 one . 8 x 6's & no Nitro , did REPEAT reverse wingovers , on the outer,
on 70 foot of .012 . ( Test Foist on 65 x .015 , as ifit went flatout on the thin ones it'd go  free flight .)
If on the eighth pull out , after initiating , you step back as you slam on opposite control -
The Whole Crowd whos heads have been going left right left in sympathy , will duck at the knees in shock .
 VD~

So These things arnt BAD .

YAW :

Me 262 = NONE .

Whirlwind = if you dont get jumpy  , read smooth  delicate handle movements - perhaps the smoothest manouvres .
                  This , on initial tests , in a good rural steadyish breeze , Porpoised . Say 6 inch odd . After Furver Fort ;
                 We OPPENED the HANDLE SPACING . and got delecate . It Tracked STRAIGHT then .
                 The lack of GROOVE had been DIFFERENTIAL LINE STRETCH , the yo yoing  in stretch , withem CLOSE
                 ment lack of track . With it further apart , the delicate touch let the handle wobble in synch. !  :o
So RIDGID handle holding had caused it. in a manner of speaking . If you fly with it out on your FINGERS rather than palm it ,
                Its more sensitive / responsive , to light miniscule & sub Concious ! input .  :X

ILLUSTRATED , as Kieth asked IFIT initially went opposite , with the T - Tail . I believe i observed and automatically counter steered initial op reaction to input , with the high T Tail .
                thinking on that , Not to long later . AND Id Burnt Gallons , back then . Regularly . so was Tuned In & with it . Man .

xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

So if your on stretch 15 thou. stainless , If figerin THAT is most of your ploblem . Let a smart assed teenager have a goatit , if he can fly . they automatically do things , with a less ridgid approach .

TRY gluing some of my ' WING FENCES ' on , Theyre 7 inch out . Some Peoiple call them NACELLES . or sumsuch THING somewhere  .  To Override gyroscopic hoodads and suchlike .

xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx The Mosquito is touchier to Yaw / control input . With ten foot of side area Fwd. & none aft. As it were . Has spun out & pulled a nacelle off with the prop in the lines  , recovering from inveted , in the wind .
But a Hot @#$% ' Combat ' Ship  . & deadly accurate F2B IF you fly it fingertip & touchy  - minimum hand movement , like . Hair Trigger .

the T Tail is steadier , smoother in itself as it were . Youd have to go at it   like a lout , and it'd yaw . Can get a roll - lift a wingtip . Sometimes does sometimes dosnt . More if it CRAWLS around on a dead inner .

SO THE ENGINE RUNS A LOT TO DO WITH IT . Good Polised 18 thou , 60 or 63 foot . & on 20 % jungle juice - YOURS COULD BE ROCK STEADY .

Like the 262 .  n1

Temorarilly tacking on a few sheets of scrap , with cut outs for the flaps . Or a ennormous Netezband V fin set up , might learn ya summit too .

http://www.controlline.org.uk/userupload/613/0005.jpg


These things tend to improove with age . ( engines are dead equispaced ( Thanks to those assymetric ribs ) .
Foist W W 38 ounce
Foist 262 41 ounce . ( bth OS max .20 backin 74)
Mosq. Initially 60 Os , & climbing . Veco BB 19 (Toin of centry )
WW maybe 55 , who knows ( Its Got Foxes 19 / 25s )

Me 70 , or 72 . or 76 !  :P No bounce bobble or mush on 70s of the .018 at around 5 or so a lap thereabouts , Doubt faster . A wham wham HIT the Corner - TIMING - approach . broad andle movement .THERE .
But it dosnt know what yaw is , unless your drunk .

AND the cenre of gravities about backathe SPAR  , so theres some sort of Mass Stabiliseation Effect going on , BALANCE - Conter Forces balancing forces - stabilises . Like a car on good wide tyures, with that .
whereas the other two are more like moto crossers , touchey . With the T Tail being mid field . So ALL THIS appears to be related to Side areas / Distribution = Line Tension . Steadyness THERE giving something.
unsteady Tension xxxxing it all up . Combined with inadequate wire . your Doomed . TRY the olde Rag down free line to rotate out Stretch . Try some hevier cables and get it moving . It may be just a dither .  >:(
These Dont . & I wouldnt try it . Trash motor runs & theyre trash . Rather than their usual perfection .  ;D   LL~   ;)
« Last Edit: December 03, 2024, 10:45:55 PM by Scientifiction . »

Offline Perry Rose

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Re: Brodak Oriental
« Reply #4 on: December 04, 2024, 06:11:36 AM »
I'm building the profile version now. The instruction book step 53 says an inch shorter right wing. The wobble you mention, is that in the last corner of the square? If so it is a stall and I have found, through painful experimentation, that the flaps block the air to the elevators or disturb the air. I found that the fix is to increase the elevator travel and/or decrease the flap travel.
« Last Edit: December 04, 2024, 07:45:14 AM by Perry Rose »
I may be wrong but I doubt it.
I wouldn't take her to a dog fight even if she had a chance to win.
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Offline Air Ministry

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Re: Brodak Oriental
« Reply #5 on: December 04, 2024, 08:00:21 PM »
Indeeed . Im running something like 20 - 30 ( 30 - 45  ;) ) flap to Elev.

Looking at the drawings the other week , Ive got 17 1/2 to 21 on the tail moment ( Across 10 or so semi scale - The Meteror being the 21 . NOW I can doit smaller ! )

SO , Mention of the TWISTER WING being identical 2/3 foot by 4 foot plan ,  " We " can now do  ' FANCHERISED ORIENTALS ' Move the tailplane back to the end of the fuselage .

                                                                                                                                           
We'll have toget Ted ontoit . He used a leadout slot , with like rivets on leadouts to plug in the holes forem there . Pulling the leadouts around like that'd be a good start .
Chaps .

But , the little ole OS max . 35 ! Flew the 50 Oz Phantom with the 10 x 4 3 blade , running slow , on 70 foot of .012 . IN THE CALM . It seems o.k. on Long Line with the FSR .25 on 70 foot of slack . 016 it still steers.

BUT , overpowering one , with say a ST 46 for instance , or using a LA 46 , might get enough ' drive ' to sort it out . As your less in the ' delicate ' range . If your large brutal pilots .  S?P

The FP is only about a match for the old OS max .40's , so THEY should be just as good . Theres also a ' C ' &  r c .35 Single Ball Race . same piston as the .35 S , but rests near a old 40 - S .
Yet to test these's stunt capeability . The Liners bigger than the 'S' , so the ABC wont go in .

Try Adjustable leadouts , or your going to have to balance to suit YAW , to eliminate it  . As I Said , a steady speed sorta sorts it . If its stopping here & there , its not gunna fly straight .  H^^

Offline Jim Svitko

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Re: Brodak Oriental
« Reply #6 on: December 05, 2024, 08:32:07 PM »
In my time in this hobby, I built two Orientals.  Both full fuselage versions, and with foam wings.  The first one is no more, having worn out, so to speak.  The second is still flying.  The first was built with longer inboard wing, per plans.  The second was built with equal span wings.  I could not see any difference in performance between the two.

The Oriental flies reasonably well, as long as the wind is not too bad.  The stab/elevator area, in my opinion, is insufficient.  In any kind of wind, corners are an adventure.  I nearly lost my second Oriental on a breezy day at a contest.  It did not want to turn in breezy conditions.

Regarding the yaw oscillation you mentioned--I have two planes, quite a bit different in design from the Oriental, that had a nasty yaw oscillation in corners.  I tried everything to fix that but nothing worked.  I ended up moving the leadouts forward on both planes and that fixed it.  So, maybe you can experiment with leadout position and see if that helps.




Offline Air Ministry

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Re: Brodak Oriental
« Reply #7 on: December 06, 2024, 07:22:12 PM »
Hurumph .

Correct  the C G to 1/2 to 3/4 in front of the rear of the sheeting .

It Is a relitively thin wing 1 3/8 th odd , Bansheeish whereas the Twisters nearer two .
But I think a Heavy Duty Control Set Up is the Heart of the Matter . Along with a sane flying speed .
There not a ' walking pace ' stunt ship . Hence the 262 on 70's is covering a bit of ground . 60 mph ?

the TAILPLANE , if its STIFF & ' locks in regard to the bellcrank ' , ii.e. , Has no bow or give -
when you try and lever it against secure leadouts .

The bloke that did a .35 Folkerts Speed King , had a removeable inner tip block set up .
If you had the leadout slot ( in the curved tip ) with the adjustable line guide at the RIB ,
It'd be fairly straight forward . Or a pullable strip chordwise multi grooved for guides ,
Lift - shift & refit . Rather than having a ginormous hole in the inner tip .

The twins with the ORIENTAL WING , I just fly , the later 262 was the only one I threw noseweight in . If we dont count the NF 11 Meteor with a 1/2 x 3/8 hardwood tailpost .
These things fly about One ' G ' in line tension . So steer as theyre not on slack lines .

Oriental was pre the Heavy Duty Control System era . But benifit by it . Was a matter of course to fit say a 2.7 or 3 m.m. horn , and brace the pushrod .
Using a timber pushrod ( ba good piece of 1/4 x 3/8 or so ramin or suchlike , the expansion with temp. & humidity , mathes that of the fuselage , so ' adjusters ' arnt needed .

added this  ,
https://outerzone.co.uk/images/_thumbs/plans/6494.jpg


With Those 1/4 Sq leading edges , ' one ' marks 1/16 fwd, on the angle ,of the flank , top & bottom . Ditto ? Fwd. Chop off the front 1/16 of the 1/4 sq. then remark the centerline Fwd .
Get a long ? one foot , sanding block . STRAIGHT . And New 80 Wt or cooarser , and have at it . IF you do the same ' cuts ' top & bottom , flipping the wing , at the same angle , your
whacking the same amount off . A HB or thin pen line - All equal - to ' cut back to ' for starters , for the FLANKS , lengthwise .
THEN round off useing the block chordwise . Talking about 2 to 6 strokes , generaLLY , PER GO . tHEN GET THE 120 OR 180 OUT . and youll have a nice ROUNDED leading edge .

Someofit will be Operating Temp , up past 20 degrees , then at 30 plus , there isnt as much air in the air . I find the things reasonably ' snappy ' & a fair groove , if left to it .
Bobble on exits , first thing Id checjk is stiffness - Flaps to Elevators . An awfull lot of planes  have fairly soft / light horns . UNBENDABLE ones see it all stays in direct relation .

What you cando with the leading edge , thereabouts .


Take as 1/4 sq. & 1 / 16 sheet .  you doit something like that , anyway . LONG sanding block , rough out with 80 Wt. doiing sequential - to get it EVEN . as in 2 or 6 strokes , flip , repeat the same .
Comes off pretty quick , so dont lean onit to hard . The GLUE will be the thing to lookout for . As it can be way harder than the wood . and catch you there . you can use a Big File , if needed . there .
« Last Edit: December 10, 2024, 07:03:52 PM by Scientifiction . »

Offline Chuck_Smith

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Re: Brodak Oriental
« Reply #8 on: December 16, 2024, 02:03:07 PM »
Scientification,

I'm having some difficulty unraveling what you're trying to say but a couple notes:


i. this is NOT a profile Oriental. I used an Oriental wing off a well-flown full fuse version. This model has different tail volume coefficient to modernize it. 

ii., I have been using heavy duty controls including arrow shaft pushrods for decades. While I'll never say never, I'm fairly confident with them

iii., The issue is a yaw stability problem, plain and simple. 

You may feel free to use math in explanations, I'm an aerospace engineer with multiple degrees.

I'm leaning now towards the root of the flaps. I may install fairings and see what happens. Many a plane has had yaw issues due to wing fuselage interactions.

I mean. this was just a fun side-project and it never gets sorted my world will still be round.

The REAL project is a semi-scale BEE GEE stunt ship. Not a Max Bee, but a semi-scale BEE GEE. If Walker can fly a B17 I can fly a BEE GEE.

Thanks,

Chuck
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Offline Air Ministry

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Re: Brodak Oriental
« Reply #9 on: January 02, 2025, 09:56:57 PM »
The ' lifting body ' concept has some merit .


A kiwi ran a profile R C thing for aerobatics ( control line ) which unblanketed the wing .

If the ORIENTAL is got stiff wood for flying surfaces , and a bit of tow , 70 foot lines would get it moving . the 262 is a Oriental wing . at 70 ounce plus , it flys excellently . Though I dont like the disruption / drag
from undercarrages , much . A caudronish thing 's had a dozen engines in it . More Power always makes it less saggy . the AUTHORITY - power wise . Like Dodge 440 Vs Morris Minor , perhaps . good to have it there .
The SF .46 seems as good as any , in the last centurie ' stock ' engine stakes . It keeps it moving . But anything that isnt , it gets unttidy . So try a ST 60  S?P ( the old ' if it dosnt fly put a ST 60 in it , theory ).

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