RC India

General Topics => RC People => Topic started by: prafulla on August 11, 2018, 10:11:45 AM



Title: 1.3m wing span 430g slow flying Orinithopter
Post by: prafulla on August 11, 2018, 10:11:45 AM
https://youtu.be/FZa13-YvjIE


Title: Re: 1.3m wing span 430g slow flying Orinithopter
Post by: prafulla on August 11, 2018, 10:13:30 AM
with 1500 mah 7.4V flying time - 25min
       1000 mah 7.4V flying time- 15min


Title: Re: 1.3m wing span 430g slow flying Orinithopter
Post by: Voice of deaf on August 12, 2018, 06:52:48 PM
Awesome build, 


ps: Would love to have plans if available


Title: Re: 1.3m wing span 430g slow flying Orinithopter
Post by: rastsaurabh on August 12, 2018, 07:30:46 PM
Very Nice Bird and good fly time.
It will be great if you can put up closeups of mechanism and built material.


Title: Re: 1.3m wing span 430g slow flying Orinithopter
Post by: taksh on August 12, 2018, 07:37:08 PM
Nice build.
please tell information like Electronics and gear box


Title: Re: 1.3m wing span 430g slow flying Orinithopter
Post by: prafulla on August 12, 2018, 08:11:21 PM
Dear friends most of the gear casing i design with software then cut with cnc and this bird is still in design . I can show u a view of the gear casing for experiment . but the final version is cut in carbon fiber . As a product it is going to lunch in rcwing.in website. Even today i fly with 1300mah 7.4V which i got a better result than 1000mah . So it is still in design. 
 

https://youtu.be/VmzjGLnZfuo


Title: Re: 1.3m wing span 430g slow flying Orinithopter
Post by: K K Iyer on August 12, 2018, 08:54:28 PM
with 1000 mah 7.4V flying time- 15min
The flight in your video is excellent.
Assuming you are using 75% capacity, consumption is 750mah in 1/4 hour, or at the rate of 3amps.
With a 2s that means less than 25 watts.

In the video you mentioned weight of 430gms. And a 2212 1400 kv motor. That motor must be about 120 watts or more, so you must be using only 20-25% power.

I have a powered glider (Sunbird) with an 2805 motor on a 1300mah 2s, that weighs about the same (450gms).
But I’ve so far never got anywhere near 15 minutes under power.

When the rain stops, I’ll try if I can get 15-20 minutes of powered flight.

Meanwhile, I wonder if
1. An ornithopter is more efficient than a powered sailplane?
2. Or, your duration estimate is perhaps rather optimistic?

Either way, your achievement is wonderful.
Regards


Title: Re: 1.3m wing span 430g slow flying Orinithopter
Post by: prafulla on August 13, 2018, 09:20:56 AM

Dear sir Still my design is not time Optimize it should fly around 20min in 1000mah , 7.4V , 20C lipo , Normal takeoff is around 22 to 23W and 18 to 19W on flying ( it can also be fly in a small space depend on pilot skill ) you can see my first test flight i given more throttle which take the bird away from me with less time. People have all ready design for 1h flying with 2200mah for 600gm ornithopter. 




Title: Re: 1.3m wing span 430g slow flying Orinithopter
Post by: gaurang.1972 on August 13, 2018, 10:35:39 AM
 {:)} {:)} {:)} very good design Mr swin


Title: Re: 1.3m wing span 430g slow flying Orinithopter
Post by: rastsaurabh on August 13, 2018, 11:12:00 AM
with 1000 mah 7.4V flying time- 15min
The flight in your video is excellent.
Assuming you are using 75% capacity, consumption is 750mah in 1/4 hour, or at the rate of 3amps.
With a 2s that means less than 25 watts.

In the video you mentioned weight of 430gms. And a 2212 1400 kv motor. That motor must be about 120 watts or more, so you must be using only 20-25% power.

I have a powered glider (Sunbird) with an 2805 motor on a 1300mah 2s, that weighs about the same (450gms).
But I’ve so far never got anywhere near 15 minutes under power.

When the rain stops, I’ll try if I can get 15-20 minutes of powered flight.

Meanwhile, I wonder if
1. An ornithopter is more efficient than a powered sailplane?
2. Or, your duration estimate is perhaps rather optimistic?

Either way, your achievement is wonderful.
Regards


Sir, What is understand is that the motor is literally running on no load.

notice the 2 big Spur gears.... exact ratio prafulla can confirm.



Title: Re: 1.3m wing span 430g slow flying Orinithopter
Post by: prafulla on August 13, 2018, 11:45:22 AM
just watch this video

flying time of 1h with 2200mah (18W )
From IITK ,
 
https://youtu.be/poX2Hg9qae0


(18W)
https://youtu.be/EOBKZLLsfzk


Title: Re: 1.3m wing span 430g slow flying Orinithopter
Post by: K K Iyer on August 13, 2018, 04:36:29 PM
@prafulla,
So it really needs less than 20 watts!
Wow, learnt something new.

That IITK video brought back memories of the aerial view of the Gliding and Soaring Centre, not seen again after leaving Kanpur in 1982...
Regards


Title: Re: 1.3m wing span 430g slow flying Orinithopter
Post by: sanjayrai55 on August 13, 2018, 05:45:45 PM
Why "Smart Bird by Festo"

To my limited knowledge, Festo is a major manufacturer of pneumatics. Were they sponsoring this?


Title: Re: 1.3m wing span 430g slow flying Orinithopter
Post by: prafulla on August 13, 2018, 06:14:23 PM
I hv not got time in college now i am home see the gear box design by festo ( I showing festo smart bird because they used 3 big gear )

Let me explain if u observe the gear box by festo it is 3 gear and the motor is compact 135 each wing i guess around 100g so if motor alone is response for lifting then with full throttle allso can't lift . its the design of wing ( Lifting line theory ) that generate lift during flying . only a small fraction of power ( about 15 To 20% of throttle is used for flying ) form motor is consumed during flying. Even for my bird I used just about 40% of throttle for takeoff during flying i used to keep just about 20% of throttle. if i go above 70% by( only possible in holding it will damage the model )


Title: Re: 1.3m wing span 430g slow flying Orinithopter
Post by: K K Iyer on August 13, 2018, 09:13:16 PM
@prafulla,
So it really needs less than 20 watts!
Wow, learnt something new.

On second thoughts, I realised that efficiency is not just a matter of duration.
One needs to consider the ability to cover distance too.

Not going further to avoid diverting your thread...


Title: Re: 1.3m wing span 430g slow flying Orinithopter
Post by: anirudh4d97 on March 01, 2019, 10:39:46 PM
sir, I have designed wing 900cm and frame (acrylic) is 250mm lngt and 15 hght approximately. any suggestion and need help for specification