Revised Bumble Plane 332 Gram Twin Boom 680 mm

by nickatredbox | March 11, 2013 | (5) Posted in Projects

Revised Bumble Plane

Revised nose section Depron covered with tape 40 Grams, Half the weight of the foam board

New larger tail 35 Grams, 60 Grams for the foam board one

Wings are 105 Grams

Take off weight 322 Grams with Rhino 610 3C

New dimensions Span 680 mm length 680 mm

 It looks more in proportion now 

The spars are 5 mm square carbon I think it needs to be a bit stiffer tortionally 

 

 

 

 

 

 

New Baby Twin Boom 700mm Bumble Plane

New Baby Twin Boom 700mm Bumble Plane

Maiden Flight Here

With any luck will give it a flight in Akaroa tomorrow




Foam Board, hot glue and tape
Span 700 mm
Length 730 mm
Flight weight 385 Grams
C20 1550kv motor 
6X4 APC prop delivers 385 Grams of thrust @ 9.7 Amps
Turnigy nano-tech 460mah 3S 25~40C Lipo Pack 45 Grams

2 X 2.5 gram servos 
Hobbyking SS Series 8-10A ESC

The tape weighs 15 Grams and add so much durability in a crash
 


 

The wing is a 200 mm chord with a 10 mm under camber shown above. It has a single aileron and elevator.

Wing Area: 14 dm²    1.5 ft²
Wing loading: 28.57 g/dm²    9.37 oz/ft²


 
 

 

Bumble Plane Maiden


Flew Ok not great elevator Authority, roll was Ok the aluminum spars were too fragile it got bent on the back of the car before I flew it. Sadly no video today but it was three 1 minute flights before I killed a servo

 
I also used the bad method launching and the razor sharp APC prop gave me a nice  cut on the back of my hand. Blood letting aside it flew Ok with a 3 cell Rhino 360 mAh. Ran at half throttle plenty of lift at low speed, that's where the elevator is quite slow, perhaps the tail should be shorter, closer to the prop which would make the pitch rate faster, but reduce the mechanical advantage, the design from http://www.foamflyer.info has shoter tail spars. Or perhaps a bigger tail and elevator is the way to go, not sure yet will do a bit more research see whats on the www
Found this design on http://www.foamflyer.info looks like my stabilizer may be too small at 30 mm this one is 50 mm but its a bigger plane with an 880 mm span.

The tail to on mine is 2 dm² ratio of the wing area is 12 / 2 = 6

On the So.X below 4.4 dm² ratio of the wing area is 15.4 / 4.4 = 3.5 

So her tail is too small, half as small as So.X shown below. Umm?





To address the problem here is the plane with a larger tail

The tail below is 3.5 dm² ratio of the wing area is 12 / 3.5 = 3.11 

Also I will have a single tail fin I think


 
 
 

COMMENTS

Adib Vahedi on March 17, 2013
Wow looks nice the colors are like the song " black and yellow" hahaha lol!

Keep up the great work!!!!!!!!!!!
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ronnie.burchfield. on March 11, 2013
nice plane i will try to build this . do you think i could use adams dollor tree board foam ?
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nickatredbox on March 11, 2013
It is foam board mate. I use the tape just to make it a bit more robust . I will be making the bigger tail this week if I get the time see if it fly's better
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Revised Bumble Plane 332 Gram Twin Boom 680 mm