Thread Tools
Mar 15, 2015, 09:35 PM
Registered User
jason f's Avatar
Thread OP
Discussion

Flipping Bi-Copter !!!


Check out my flipping Bi-Copter !

Keda 2730 24g 3000kv motors
MultiWii flip controller
Power Up 17g metal gear micro servos
B-12A ice blue series simonk sec's
5x4.5 bullnose props
850mah 3s lipo
285mm scratch-built Bi-Copter frame

Weight with battery is 11 oz

MultiWii flip controller settings:
Roll 3.3 // 0.030 // 23
Pitch 1.0 // 0.009 // 6
Yaw 1.8 // 0.013 // 0
TPA: 0.00
RC rate 1.30
RC expo 0.55
Roll Pitch Rate 0.26
Yaw Rate 0.21

Thanks for watching guys, enjoy!

(1 min 55 sec)
Last edited by jason f; Mar 16, 2015 at 06:48 AM.
Sign up now
to remove ads between posts
Mar 16, 2015, 12:52 AM
Zippa Flippa
nebbian's Avatar
That's flying really well, congrats! Looks like you've got it dialled in quite nicely. I'm really not sure about how the physics works after a flip where the body sort of pendulums back and forth a couple of times, obviously it's doing it but I would have thought that this wouldn't happen.

What's your all up weight and flight time? What size props are you spinning? Have you considered making a body that looks like an All Terrain Scout Transport like in star wars? It reminds me of that anyway

Great job :-)

Mar 16, 2015, 01:43 AM
Registered User
polkadot's Avatar
i love the frame design! gorgeous arc. really elegant simplicity
pretty snazzy flying too

ive been interested in bicopters for ages, this just makes it look way more exciting than anything ive seen before.
Mar 16, 2015, 04:01 AM
Registered User
RCvertt's Avatar
Cool stuff man. That bi looks rock solid on stability and the flips are well done. Digging the frame design also.
Mar 16, 2015, 06:49 AM
Registered User
jason f's Avatar
Thread OP
Quote:
Originally Posted by nebbian
That's flying really well, congrats! Looks like you've got it dialled in quite nicely. I'm really not sure about how the physics works after a flip where the body sort of pendulums back and forth a couple of times, obviously it's doing it but I would have thought that this wouldn't happen.

What's your all up weight and flight time? What size props are you spinning? Have you considered making a body that looks like an All Terrain Scout Transport like in star wars? It reminds me of that anyway

Great job :-)

I updated the original post with prop and weight info. I think flight times are 4 or 5 mins.
Mar 16, 2015, 01:27 PM
Registered User
Very cool!
Mar 16, 2015, 02:05 PM
Registered User
Great job!
Mar 16, 2015, 08:46 PM
Lipo Burner
dcame002's Avatar
wow. I was already impressed by the rolls...then it flips!!! Good work man- love the simplicity of it all.
Mar 16, 2015, 08:48 PM
HighFlyGuy
highflyguy's Avatar
Looks great, so smooth!
Mar 16, 2015, 11:43 PM
Zippa Flippa
nebbian's Avatar
Actually this one is closer :
Mar 17, 2015, 08:44 AM
Winging it >
leadfeather's Avatar
Very, very impressive! The best bicopter flying I've seen.

Love the super simple motor mounts. Great!!
Mar 17, 2015, 08:52 AM
Registered User
jason f's Avatar
Thread OP
Thanks for the nice compliments guys. It's been a fun project. I plan to keep improving the design.
Mar 17, 2015, 07:01 PM
Registered User
Absolutely the best design I've seen. New to me but maybe there are others similar. How do I build one - or do I have to buy one? Very
Mar 18, 2015, 09:39 AM
Registered User
Ran D. St. Clair's Avatar
Very Nice... I am impressed by (among other things) how quickly it damps pitch oscillations.

Would you care to speak to the keys to success from a technical perspective. Correct me if (when) I am wrong.

1. Keep the motor tilt axis up high, and the CG down low, or more specifically, make sure they are far enough apart.

2. Use fast motor tilt servos, to insure adequate stability bandwidth.

3. Use a FC with a high frame rate, like 400Hz, because it is a fairly small model.

More?
Mar 18, 2015, 05:19 PM
Registered User
jason f's Avatar
Thread OP
-Keep the cg as low as possible to tame the pitch axis from swaying.

-The copter is balanced for/aft at the wooden arm holding the servos.

-Must be flown in an auto-level mode to manage the pitch axis from swaying.

-I fly aerobatics in horizon mode (multiwii), which allows the copter to exit auto-level mode and enter manual mode temporarily when the sticks reach near full throw.

-I have the flight controller mounted up high, inline with the servos (pivot point). If the flight controller was mounted down low, it would sway more, gyros/acc would probably go crazy.

-I think PID's need to be lowered a lot when outputting to servos vs esc's in general.


Quick Reply
Message:

Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Bi-Copter doing flips!!! jason f Scratchbuilt Multirotor Drones 17 May 14, 2014 01:20 AM