Six Different Quick Build Fun Planes

[Tom Wright 2]

At last ! got my u tube account sorted out ,can now up load videos to suit the forum requirements,another small step in the battle with modern technology.IMO building and flying is much easier.

Thanks to Pete for turning out ,he wasn't feeling so good ,but still managed to shoot the video.in the cool blustery conditions.

Have some ideas about a delta using the same materials,so now the technology clutter has gone from my head i can start work on this new project.

 

[Tom Wright 2]

Answers to questions.

 

Tail incidence 0 to keel.

Wing incidence ,set by cut out in "pipe" + 3 degrees.

Motor down thrust 4-5 degrees.

Motor side thrust right 2 degrees.

Nose length l/e to fire wall 8.5 ins.

Wing t/e to tail l/e 15 ins.

Tail span 14 ins .

Tail chord 4 ins

Elevator chord 1.5 ins.

Rudder height 6 ins .

Fin chord at base 5 ins.

Rudder chord max 2.25 ins.

Wing span 36 ins .

Wing chord 8 ins.

AUW 9 ozs.

[Tom Wright 2]

CG one third of chord from wing L/E .

[Tom Wright 2]

Further test flights tomorrow ,will it fly inverted ? and will it bunt ?i suspect these maneuvers will exceed the structural limits but i don't expect repairs resulting from structural failure to take more than 10 Min's to put right.

[Tom Wright 2]

Destructive Fight Test Results.

 

Inverted flight..........Entry only possible from the top of a loop maintaining inverted circles was quite easy but control was very limited.

 

Loop ...........no problem.

 

Bunt............Surprisingly easy ,plenty of wing flex but no problem.

 

Sustained dive.......Resulted in wing flutter and failure at the center section,this result was predicted .

 

Repair time less than 15 Min's.

 

Conclusions .

If flown in a considerate way many trouble free hours of flight could be expected.As the air frame costs less than £5 to build the concept is best left as is ,additions or mods that add weight would ,involve a complete re design.

A slightly shorter wing span and nose / moment arm would probably result in a very practical model,do not exceed the 500ma battery size ,or power rating of 35-40 W .

 

Obviously the further development of such simple designs results in the shockie ,but this one is more suited to relaxed fun flying or air experience flights, were little control input is needed to maintain flight ,just a touch on the rudder now and then should do the trick as the spiral stability is very good.

 

Tom.

 

 

 

 

[David Perkins 1]

Good evening Tom,

 

Being quite new at this and fascinated by your model, a question; does the wing have any camber, or is it just slightly sanded at the LE and TE reducing to match the balsa struts?

 

Would there be any problem in gluing two sheets of 3mm Depron together to make the wing? I have plenty of 3mm but no 6mm........

 

If I use 3mm Depron, would it be advantageous to introduce any form of camber into the wing by introducing a longeron between the sheets, or am I trying to make life to difficult for myself?

 

David

 

 

[Tom Wright 2]

Good Evening David,

The utter simplicity of the design is very much based on a flat wing ,with the balsa l/e and t/e just rounded ,no sanding of the depron is required.

A cambered wing would generate more lift ,but if the weight is kept to the suggested figure the simple wing performs perfectly well .

Joining two sheets using a spray adhesive would be ok the idea is to keep the glue weight down,

Hope that answers your questions ,if you intend to build one let me know and i will let you have the mk 2 specifications.

 

Tom.

Edited By Tom Wright 2 on 15/06/2011 22:43:53

[Tom Wright 2]

Built another one today shorter nose and moment arm with the span reduced to 32 ",will let you know the results of the test flights.

[Tony Bennett]

you keep banging them out tom.

dont you ever sleep.

[fly boy3]

Tony, if you look at the time of some of Tom's posts, you will find he is a night bird.I think this is when he does his building. LoL

[Tony Bennett]

i have noticed the 2 am posts.

i paid 79p for my pipe lagging at B&Q's

and 90p for the square section timber.

[fly boy3]

Got to be the cheapest r/c flying model in the UK. Cheers

[Tom Wright 2]

FB3 Tony

Built another one last night ,it took 2 hours to complete the air frame waiting for some micro servos to arrive,these will be fitted in the tail to eliminate the long push rods .

Tom.

[Tony Bennett]

humpf.

 

 

[Tom Wright 2]

Latest version with carbon boom.

 

Could call this the super deluxe version LOL.

 

Edited By Tom Wright 2 on 16/06/2011 14:53:45

[fly boy3]

I like to delve into the basics of the design now and then. Tom can you tell me why there was a need to shorten the nose, and what effect does this have on the flight of the model. Cheers

 

Sorry ,this could be a double post.?

Edited By fly boy3 on 16/06/2011 17:35:43

[Tom Wright 2]

Good question FB3.

This model has a reduced wing span ,34",the idea was to reduce the load on the center section butt joint.

As the nose and moment arm are shortened to maintain the original proportions ,the weight is decreased which in turn lowers the loading on the wing joint even more.

One oz =10% of the AUW......... and a 10% increase or decrease in G loading.

[Tom Wright 2]

MK 3 Wing plan form avoids adding wing center section braces ,still got to attach the l/e and t/e 3/16 balsa to finish off.

 

 

 

Could call this one the floater deluxe lol .

  Edited By Tom Wright 2 on 16/06/2011 20:16:00

Edited By Tom Wright 2 on 16/06/2011 20:18:25

[Tony Bennett]

you do manage to keep building them fast tom.

 

the design is getting better and better.

[Tom Wright 2]

Cos there is very little work involved Tony.  Will test fly it tomorrow.

Edited By Tom Wright 2 on 17/06/2011 02:01:31

[fly boy3]

Hi Tom, thanks for thedesign question answer,I really should find time to read the books. "Cos there is very little work involved" This statement is incorrect Tom, you are forgetting the design phase, which ensures that non designers like myself can build a model that has been proven to fly well. Cheers

[Tom Wright 2]

Hi FB3.

Building and flying very simple models ,and then experimenting ,to find out what effect various ,changes in the design have on the flight characteristics,durability and primary structural strength,is a practical way into basic design,after a while a second sense develops that assists in predicting flight characteristics from the planning stage.

 

Although the fundamental requirements involve structural engineering ,aerodynamics,

control and stability etc ,a degree in such subjects is handy but a firm grasp of the basics as often discussed on this forum is all that's needed to have a go.

 

Beginners often make the mistake of tackling a complex scale model ,and then attempting to fly it with a crowd of admiring on lookers ,not a good idea!

 

All own designs should be considered as experimental and test flying should be under taken in a safe area by pilots of appropriate experience.

 

Simple cheap models still obey the same laws of physics ,as the complex expensive jobs so have fun.

 

The purpose of this thread is to to to remind others that every day cheap materials can be used to build a fun model and to relate building and flying experiences along the way its not a specific instruction on how to build a particular model ,as this would require more details ,but the general theme should be enough to do your own thing.

 

 

Edited By Tom Wright 2 on 17/06/2011 14:42:20

[Tony Bennett]

well put tom

 

not all of us can afford £250 for a rtf.

[Tom Wright 2]

One things for sure Tony a £ 250 ARTF is likely to end up as a bag of bits if crashed, where as a simple light design along the lines of the models on this thread can be repaired in a matter of minutes.

[Tom Wright 2]

Here is a simple example of designing a variable lipo position ,this makes it easy to observe the change in flight characteristics for different CG settings.

Very lightly loaded models can sometimes perfom better with a CG further back than the norm,but make small adjustments at a time as eventually things reach a point were the pitch stability becomes a problem.