Cybertom

BEST STOCK STEARMAN AIRSHOW PERFORMANCE EVER!!

I can do one better than that Chasrb. Look at this awesome video. My goal is to have my Stearman as good as this. If this doesn't get your imaginations going you would have to be clinically dead!!!

[link=http://www.youtube.com/watch?v=ObkFd-so1xo]John Mohr Stearman Airshow[/link]

chasrb

WOW, I liked that one! Too bad we could not see the end of it.

I chatted with the guy who bought out Bob Dively and asked him about his Stearman kit. I think when he get them back into production that is one I am goingto build. It is taken from the actual plans and scaled down to 25%. I am not sure if it was modified in any way for model flight, but it is as scale as they come and the Siedel ST710 would work real well. He has the kit makred as discontinued until further notice because he is doing a cad conversion on them and setting them up for laser cutting.

I Just orded my cockpit kit from Dynamic Balsa today, should be okay. I am progressing, slowly, but still moving forward. I cut the sheeting for the cockpit last night and have all the major control surfaces installed and servos attached. How much overhang did you have on the sheeting above the instrument panels? Also my fiberglass cowl is white and real thick! I may get another from Fiberglass Spec when I order the wheel and tail pieces from him.

Have you been flying your Stearman Tom?

chasrb

Thread has been slow. I have temporarily put the Stearman on hold. Work has got me going a lot and I am tring to complete a Tigercat with two Saito 170's in it. It's an ARF but I'll get back in the Flair mode here shortly.

Anyone else still building or flying?

outacontrol41

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I flew my Stearman last week and my neighbor video-taped it. I was going to post it until we realized it's a whopping 478 mb. long! Don't know how I'm going to post that anywhere. I'd love for everyone here to see it. I may have to fly again and have him use lower resolution to get it in under 50 mb. Three beautiful flights with smooth as silk landings. You'd love it!

chasrb

Can't wait! Is there a youtube that can handle that size? Maybe edit out all but the really really great parts?

outacontrol41

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I'll see what I can do. Maybe I can edit out the shakey parts....we'll see.

Jacque

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I would like to buy a Flair stearman kit ,if one knows of one for sale. thanks Jacque

Harrier Mate

BobH,

Please excuse very late response. Only just found this excellent forum. I have also recently started (resumed after a year's distraction!) building a Flair stearman and, having seen a SAITO 180 (GK version) in another, decided to pursue this engine also. I understand it has plenty of power for scale flight and also (by sheer coincidence) is almost identical to the dummy cylinders provided when painted appropriately. Photo hopefully attached. Will post more photos as build progresses towards completion. I hope to join this exclusive "club" and gain valuable tips along the way.

Harrier Mate

Fellow stearman builders,

Last photos posted were of early progress. Come a long way since. Most recent photos of basic airframe attached for info. Now at that difficult stage where components need to be mated together, especially wings to fuselage accurately. Any tips on how to align accurately gratefully received before I start gluing and bulding inter wing struts. Also need to get to work with file and sand paper to profile wing tips - never a job I enjoy.

Thanks in anticipation.

outacontrol41

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Looks beautiful so far.....
I've got G62 in mine...plenty of power. Make sure you install a glow driver set up for idle to 1/4 throttle operation with a glow engine. Nothing comes down faster than a beautiful Flair Stearman during deadstick. It's just good insurance.
Now, the clock on the wall says 7 pm.....put the camera down and go have some dinner....[X(]

chasrb

Okay, now I am feeling bad, I have been ignoring my build this summer. But I did figure out how to mount my engine (Seidel St710) and still retain access to the fuse should I ever need it.

How you may ask?

I am going with the engine tube, reinforced and then cut out a 4" hole in the middle. I will then have a 6-1/16 ~ T6 1/8 thinck mount plate that I will bolt to the engine tube. I'll have about 7/8 of an inch around the outside of the tube in which to have my mount points. I figured this will be quicker that an entire new mount system.

Harrier Mate

Guys,

I'm getting close to having to consider what material to use to cover my Stearman. Easiest would probably be solartex but that might be cheating! Recommendations welcome for alternative approaches. Also keen for any advice on technique for applying rib stitching. The wings would look awefully plain without tapes and stitching. I seem to recall from the previous thread that Cybertom had some ideas but can't locate the exact position.

Having flown a friend's 1/4 scale Tiger Moth this morning (first time on a biplane) - and its still in one piece, I am looking forward to getting the Stearman into the air as soon as possible, Lincolnshire weather permitting this winter.

......and finally, as the centre section of the upper wing would appear to be the most convenient hand hold for lifting the aircraft when fully assembled, has anyone glassed the centre section to prevent helpers accidentally puncturing the thin balsa skin? Or is the word "glassing" a dirty word on a scale biplane thread?

redcesar

Hi Harrier Mate,

Check out the Cub Den http://www.thecubden.org/ site on Rib Stitching.
Or Check this place out, Scale Rib Stitch http://home.cablerocket.com/~scaleribstitch/ they do all the hard stuff, you just apply it to your plane.

On post 103 you can read how I have done it http://www.rcuniverse.com/forum/m_49..._6/key_/tm.htm

Regards,
Cesar.

Harrier Mate

Cesar,

Many thanks. Looking at the scale rib stitch web site now and will check your post 103 next.

Cybertom

Harrier Mate,

I used Stitts Lite fabric on my Stearman. Stitts sells a full scale manual for $10.00 that shows you how to cover a full scale Piper Cub. The exact same methods are used on the model. Chasrb added some full scale Stearman restoration photo's to the DVD which show in great detail all of the scale tape locations. Its exceptional information to have when building this model. I only whish I had it when I built mine back in 03.

Cybertom

UPDATE ON STEARMAN INCIDENCE SETTINGS

After more research I have found out the following:
The full scale Stearman had what is referred to as a "flying tail". In other words the horizontal stabilizer airfoil actually had significant camber which produced lift that balanced out the incidence settings of the main wings as speed increased. The horizontal stabilizer on our Flair Stearman has a symmetrical airfoil which theoretically produces an equal amount of lift in both directions. Now we have some evidence to support a theory on why the Flair Stearman model has a tendency to climb.

All that being said, a suggestion was posted by another member in the original Stearman thread to decrease the incidence in the upper wing so that the total decalage was 1-degree positive. He had no technical explanation why this would work; he basically said "just do it" based on experience. Some members stated they were going to try out this configuration and report back. Based on what I have found in my research relating to the "flying tail" configuration I am not apposed to trying this myself. Has anyone actually tried 1.5 degrees incidence on the upper wing of their Flair Stearman?

Full Scale
Lower Wing 3-degrees positive, Upper Wing 4-degrees positive, Stabilizer (cambered airfoil) 3.2-degrees positive

Flair Factory
Lower Wing 3.5-degrees positive, Upper Wing 3.5-degrees positive, Stabilizer (symmetrical airfoil) 3.5-degrees positive

Member Recommended
Lower Wing 3.5-degrees positive, Upper Wing 1.5-degrees positive, Stabilizer (symmetrical airfoil) 3.5-degrees positive

PS,
I have not yet discovered which airfoil was used on the stabilizer of the full scale Stearman, and even if we knew which airfoil it was, like everything else it would probably not scale down to have the exact same effect.

chasrb

Good to see you back in the fourm Tom! I am still at a stage where I can decrease my Flair recomended incidence of 3.5 down to 1.5 positive. Now armed with this new info from Cybertom, I will make the change. My lower is 3.5 and the horz stab is 3.5. Now that I have the mount plate cut and the Siedel basically broken in, I cna move forward and complete the project.

Cybertom

Charsb,

As I see it that's your best bet. I'm sure that eventually I will find out which airfoil was used on the full scale stabilizer. I can calculate how much lift it will create and so forth at a given speed, but that means creating new stabilizer ribs which is just to much BS for me. It's far easier to lower the incidence of the upper wing which should balance this whole thing out.

PS,
I look forward to seeing your Stearman fly. It should be the best flying radial powered Stearman yet.

Harrier Mate

Cybertom,

Thanks for the tip on Stitts lite. If its good enough for full size aircraft, I guess its a good bet for a scale model. I will watch with interest the debate on incidence angle for the upper mainplane. I increased my tailplane geometry to +3.5 deg last year on the advice provided by the previous thread and could still alter the wing if it's found a more effective set up. I'm not sure, however, of the ramifications of the lower wing stalling well before the upper wing - although suspect the nose down pitch change at first sign of the stall will be less pronounced while the remaining wing is still flying. Only danger would be if Centre of Pressure remained forward of C of G at full stall - when resultant turning couple (moment arm) would prevent nose drop and therefore complicate recovery considerably. (My 10 cents contribution (or tuppence worth in UK terminology) to the debate for what its worth!)

Chasrb,

Cybertom mentioned a DVD you had produced with all sorts of scale detailing which would be invaluable. Is it still available and, if so, how do I track down a copy? Cost?

Cybertom

Harrier Mate,

I was reading your message and my ears began to bleed[sm=50_50.gif] I think I understand what you are getting at. Personally I would prefer to keep it scale but without the proper stabilizer airfoil we are out of luck.

What is interesting to note is that this configuration is not uncommon in RC Biplanes. My Great Planes Tiger Moth for example has the lower wing set with a significant amount of incidence while the upper wing is almost flat. The Great Planes Tiger Moth has been described by many publications as possibly one of the best flying ARF ever made. There are other popular biplanes with this same configuration (YMF-5 Barth Modellbau WACO) so it’s not a uncommon practice.

Another interesting fact is that the U.S. Military originally found the stall characteristic of the Stearman to be too mild for students to recognize. The ARMY had Stearman add triangular strips to the leading edges of both main wings which caused the aircraft to have a more abrupt stall break. After this modification both the U.S. ARMY and NAVY accepted the Stearman as their primary trainer.

There is no cost for the DVD other than you must share your building experience with us here on-line. In addition it would be really nice to see a video link here to your 1st flight. Just send me your address and I'll ship it to you.

Harrier Mate

Guys,

A few photos from a recent trip to the Royal International Air Tattoo, where I was fortunate enough to be able to climb over a German-owned Stearman on static display (Yellow Peril colour scheme). I expect that you have easy access to numerous examples of full size Stearmans in the US but if anyone wants more views, I can send on CD ROM (about 40 shots).

Harrier Mate

Guys,

Very little progress over the last few weeks owing to pressures of work - learning to fly new real aircraft type (King Air) but at least the Stearman is now able to be seen in one piece (without engine yet). On display for a recent Open Day where we hosted veterens of WWII who had flown Sterarmans in training prior to operational selection.

Aerobatic_Tom

Hi fellas,

I am buidling one as well. It is slow going with having not touched it in close to a year, but now I am planning to at least put some hours on the build this weekend. Anyhow, the USD is really cheap for us over in Europe and I was thinking of getting an engine for it. I do not have the funds for a Seidel... what about a Desert Aircraft DA-50? I have not yet tried a gasser and was thinking this might be a good time to take the step. I know that sound and feel would benefit from a Saito 180 or Laser but I also would like to try the simple approach of a gasser with reliability and most of all oil-free operation. What do you guys think of the DA-50 choice?

Best regards
Thomas
Stockholm Sweden

Frank Sopwith

Guys!
shame I didn't find this thread before! beautifull!
I fly the Flair stearman for two years now; really love the plane


Basic setup: Saito 180 engine ( fit in with the other cilinders nicely): more the enough power! (but very thirsty!!!)



Futaba equipment, all incidences as per manual, does fly absolutely perfect,











She handles well in the air, sure needs lot of rudder with the ailerons, and a bit of throttle during landing, the only thing I don't like that much is that you need at least twenty minutes for assembling at the field

Greetings from "Dutch wooden shoe country"

Frank

outacontrol41

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BEAUTIFUL!!! How much does it weigh? Your plane is a flying scale masterpiece.

Deep admiration from Maryland, USA. Love your PT-17, Frank!!