Harrier Mate

I can't remember now whether it was ChasRB or Cybertom, but one of you spent a lot of time advising me on the incidence of the tailplane (sorry stabiliser in US speak!) and how you always wanted at least 3.5 deg instead of 3 deg quoted. Given that the model has a symmetrical tailplane section, an incidence of 3.5 deg will generate a significant amount of lift on its own. Shouldn't that compensate for the lift of the mainplane? Just a thought.

Harrier Mate.

Cybertom

Harrier Mate,

3.5 degrees will definitely help you not carry nearly the down trim I do. I think the idea behind the "lifting tail" is that it creates proportional lift in concert with the main wings. The faster you go the more lift the main wings create so the more lift you need from your stabilizer to counteract the lift from the main wings which keeps it flying level. The Stearman and the Fleet biplanes are apparently the only American biplanes that were designed with a "lifting tail".

As stated in the article depending on where the "aerodynamic center" is in relationship to the "center of gravity" determines whether or not you need a lifting tail. So far this is the only information I have ever found on the subject that makes any sense and has some solid math behind it.

It's going to take me a while but I plan to try using a Clark-Y (flat bottom) airfoil on Stearman II instead of the symmetrical airfoil that comes in the kit. It should be a pretty easy modification to make. Time will tell if that is the silver bullet that solves the problem with my Stearman. Obviously reducing the incidence of the upper wing is another possible approach.

I would prefer to have the scale setup if it works on a model:
Upper Wing=4 degrees incidence
Lower Wing=3 degrees incidence
Stabilizer=3 degrees incidence

The scale setup would seemingly provide lots of lift which will allow me to fly slower and more realistically. That's the drawback to lowering the incidence of my upper wing. It may balance things out but its going to reduce overall lift which means I have to fly faster just to keep it in the air. I will be happy though if it solves the climbing problem. I will gladly trade off flying a little faster to fix my 1st Stearman.

dutch49

My Feedback: (2)

Hello Cybertom, Would like to take you up on your offer of the photos on the Flair kit. A buddy of mine is considering the Stearman kit from Flair and I'll be the builder. Does this kit allow the conversion to the Super Stearman? Ailerons on both upper and lower wings and the engine cowl?? You can contact me directly at [email protected] , would be more than happy to pay for the CD and the mailing costs if you don't mind sending me a copy.

Thx, Mike

jack1933

My Feedback: (2)

Hello Tom, Am subscribed again, and am interested in the results of your change to the wing incidence.
Regards
Jack

chasrb

Hey Cybertom, back in the build again... I checked my center section and its +2.5 degrees according to my Laser incident meter as measured from the top of the center section. (so that is more LE down than up per the suggested incidence)

If you set the incedence as you said for the 1:1 at 4 degrees, wouldn't that create too much angle of attack?

As for the detailing part of the plane, not sure I'll do the cockpits or not, I may do the rivits tho.

A note my cowl is seeminly very thick and somewhat heavy when I compare it to the "green" one I have seen...mine is white.


OOkay, redid the incidence again...this time with the digital Angle pro - calibrated. I get +4.0 degrees...strange... but it'll do. I tested and calibrated multiple time and the results are the same with the digital meter...

[email protected]

Feb 28, 2009

Hello to fellows on the Stearman thread:

Considering a very light, “stand off scale� Flair Stearman. The goal is the lightest build possible, with the final result a “no lead� very light wing loading.

Trying to figure out if it is feasible to mount a used Saito FA-300TL methanol twin into
a Flair Stearman. (This engine has a single carb, and single plugs in each cylinder.)

Problem details described below.

Some background:

Most fellows mount a Saito 180 or 220 single cyl inverted.

The Saito 220 single cyl weighs 40.5 Oz. Turns a 19-8 at 8100 (No BHP rating
available, but I think it is about the same as the Saito FA-300TL twin).

The Saito twin puts out 4.2 BHP at 7000 RPM. With an 18-10 runs over 8000 RPM and with a 20-10 runs over 7000 RPM. It weighs 62 Oz. With CH spark conversion (staying on methanol), total engine plus battery plus electronics will be about 70 Oz.

(At my altitude, spark conversion is desirable for greater engine reliability.)

This is about the right weight to eliminate “lead in the nose� for the Flair, which would be required with the Saito 220 single.

Here is the problem in mounting the Saito twin:

Whoops! In looking at the Flair instructions, and the dummy crankcase housing, in no case is a pair of dummy cyls exactly opposite of each other (where the twin would go). The dummy crank case molding has a total of 7 positions (an uneven count), 6 dummy cyls and a seventh position for the inverted Saito 220 engine at the bottom

Don't see how I could get dummy cyls positioned so a twin would fit, in
light of the 7 position fiber glass crankcase molding.

Are there other dummy crank case housings with an even number of cylinders?

Would it be worth somehow building four Williams bros. Dummy cyls, and getting a crankcase housing with 6 cylinder positions from somewhere?

How about running the twin as is and not bothering with any dummy cyls or crank housing? Would it just look completely out of place?

A radial is too heavy, too expensive and too complicated for me.

Could build a different style Flair Stearman, with a round cowl enclosing the twin, but don’t know where such a cowl can be obtained, and whether it would fit onto the Flair.

Thanks. Any and all suggestions appreciated.

ElectRick

My Feedback: (2)

This has been one of the enduring dilemmas in building a Stearman without a cowled engine. IMHO, nothing looks correct except a radial engine (real or fake).

My suggestion is to consider going electric. That way you can hide the motor completely inside a detailed, authentic-looking dummy engine. Believe it or not, an electric conversion is no longer doomed to weigh more than a conventional glow or gas engine setup. In fact, my Great Planes PT-17 electric conversion came out at 12.9 lb. AUW RTF, which is actually a bit lighter than the recommended 4-cycle glow engine installation. I mounted the batteries well forward as ballast, and to my surprise, had to add zero extra weight for balancing.

Just a thought.

Rick

outacontrol41

My Feedback: (9)

At least you've reduced the probability of dead stick landings if you manage your battery strength well. I'm still in favor of a combustion engine for the sound. Are you planning on adding a smoke system?
LOL....just kidding.

How long do you think you will be able to fly on a single charge?

ElectRick

My Feedback: (2)

MY GP PT-17 uses an 8000 mah pack, so each charge gets me upwards of 20 minutes of flying. I don't really know the absolute limit, since I'm usually ready to land before that.
It's more than enough capacity, but I decided while planning the conversion that, if I was going to have to add nose weight anyway, it might as well be useful weight.

A123 batteries might be a better choice for a large airframe such as the Flair Stearman, since they are a bit heavier for their capacity. Of course, how you manage the throttle, along with motor efficiency, both play a role in per-charge duration.

Rick

greggK

Does anyone know of an ARF Giant Stearman...
Thanks

AM6

Hi all,
I have been reading all of the Stearman threads that I could find over the past couple of weeks to 'spur me on' to finish mine...it has worked.
Basically I finished my airframe @2 years ago, and had intended to leave it for 'a little while' before i covered it as I could not make up my mind what fabric to use and what colour sceme to paint....decisions,decisions.
Finally, I finished up buying 10m of solartex at the last model airshow of this season (Hop Farm - in England) so I can hopefully complete this winter.
Is anyone still building or watching this thread.... I could do with a little advice on covering a couple of area's on the Fueslage?
Thanks..

DLEVETT

My Feedback: (13)

Hi Guys,
I,ve got a Ziroli 1/5th scale Stearman that I,m struggling with on how to accurately fabricate center wing struts and the cabane struts.
It call for using music wire which I have tried but have failed to produce 2 of the same dimensions and angles with any degree of symetry.
Any thoughts or ideas within this thread? if so I would appreciate any help that can be provided.

thx
Dave

ULTIMATE120

Helloto all of this community, I am using the google translator to write inEnglish and forgive me the errors of the translator, I speak verylittle English.
I loved this Sterman en-17 and I am wondering where to buy this kit, I want to bring to Brazil and montor this work of art.
I count on the help of all models of this sayter to run this dream of pt 17

Cybertom

Right now this kit is NOT being manufactured. They hope they will in the future but not at this moment. Your best bet is to try e-Bay. Make sure you check ebay US and ebay UK.

Errol Levin

Hi Ultimate 120

If you are keen on a bi-plane and the Flair kit is not available go to the website of Flugmodellbau Barth. They make a 1/4 scale Waco. I am building one at the moment.
It is an excellent kit. There are also several forums elsewhere on RCU.

ULTIMATE120

Many thanks to all who are responding, I need the email addresses of stores that have en -17

king_arthur1953

AMR in Canada has Waco kits of various sizes. [link=http://www.amr-rc.com/]AMR RC[/link]

ULTIMATE120

thank you, I liked the model aircraft from waco

chuck l

My Feedback: (17)

Does any one know when Flair might start kitting the Stearman again? Anyone have an email address for them?

chasrb

Probably will not. Personally, I'd go with the Balsa USA 1/3 Stearman. More support and a more complete and accurate kit IMHO.

chuck l

My Feedback: (17)

Chasman,

Thanks for the reply, I'm probably going to go with the Ziroli 87" Stearman. The Balsa USA is too big for me. Transportation issue.

Chuck

horle

Hi Chuck

In German EBAY you can buy a Flair Stearman.

http://cgi.ebay.de/ws/eBayISAPI.dll?...=STRK:MEWAX:IT

best regards

Horst

Cybertom

I have to disagree with you on that one Chasrb.
1. The Flair kit is about the most complete kit I have seen other than the Team Genesis Waco.
2. As far as scale appearance, other than being off on the cabane locations by smidge the Flair kit is best out there. The fuselage on the BUSA Stearman is WAY off and the Ziroli's fuselage is not far behind. I don't understand why these manufacturers are so far off because you can easily buy full scale blue prints from Boeing.

PS,
I have yet to see a BUSA Stearman fly well. Maybe all the guys I have seen are setting them up wrong but it but I have seen 3-BUSA Stearmans fly in person and all of them were being constantly corrected by the pilots even during level flight.

chasrb

I knew I could flush you out of hiding Cybertom!!!

The flair is a great kit no-doubt about it, just has some quriks.

Cheers

barnstrmr

First nice work second I need your help I inherited I Flair Stearman but I need the plans for the Upper wings do you have coppies or know where I could get them.
Thanks