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VRWolf
28th January 2012, 05:18 AM
Past little bit I've been working on building a OAT Bi-copter from scratch,been a good learning experience! The other day it had it's first flight... short but with no major incident :)
discovered a few things to tweek, gyro gains, different landing gear and few other things. I'm hoping to eventually stuff some fpv into it once I get the handiling of it down.
Was inspired by Gress Aero's bi-copters and decided to give it a go and see how it does. From my testing it lifted 3.1lbs of DSLR camera and lens at just over half throttle so it seems to have a good amount of get up and go :)

Broke out the lighting and took a pic of it.
http://vrwolfphoto.com/vtol.jpg

Traveller
28th January 2012, 07:51 AM
Looks cool! do you have some more pic's and spec's?

VRWolf
28th January 2012, 04:30 PM
Thanks!

Specs:

Width- 27 inches
Length- 28 inches
Hieght- 12 inches (top of stabilizter)
Weight- 3.8lbs (with 2 2200mah 3s batts)
Motors- Turnigy 3632 1500kv
Props- master airscrew 12x6
Board- HK V2.1 (atmega 168pa) quad board flashed for twin-copter
ESC- Birdie 50a/3a bec
Frame- Custom from 3/16 ply
Tilt arms- made from aluminum/ 5mm heli shafts in ball bearing hubs
Servos- Futaba standard
RX- spectrum 6ch
Both Servo arms and tilt arm hubs are from recycled hard drives, the canopy is packaging from a set of wireless headphones I got not long ago from the Source... just a little reshaped with heat

Making feet for it today, thinking round bottom so it slides without hooking if it drifts

Here's a video of it's maiden flight... bit hard to see, that why I did a redesign with canopy
http://youtu.be/lPTb3aWbjos

More pics,

http://vrwolfphoto.com/vtol2.jpg

http://vrwolfphoto.com/vtol3.jpg

http://vrwolfphoto.com/vtol4.jpg

http://vrwolfphoto.com/vtol5.jpg

Kodalith
11th February 2012, 01:30 PM
It would be very helpful to see how you wired up this bicopter to Hk board. I have been thinking of building a bicopter but, not sure how it wires together with the board. Mixing servos and esc is unclear. thanks,

VRWolf
11th February 2012, 03:44 PM
Hi Kodalith,
First off, I'm a little new to this myself so my explinations are a bit limmited.
As far as the HK board, I have discovered that it alone is, well... not the best for the setup. I also have a bad board so I'm going to take this opportunity to switch to a MultiWii system. I don't know much about it yet, kond of learning as I go, But I've seen them fly on youtube videos and it looks like they'll be a great platform once set up properly. Unlike heli's, quad's, hex's and octo's bicopter don't tilt the whole body in forward movement much which also makes the better when encountering wind too.
But to answer your question, the wiring is simple to the HK board the first 2 output on the board are the ESC's and the second 2 are the tilting servos. The board does the rest when flashed with twin-copter firmware from KKmulticoper.

Here's a link I got from another who's successfully built and flown bi-copters for MultiWii info http://www.rcgroups.com/forums/showthread.php?t=1261382

Hope this helps

I have found my design lacking in strength so I decided to switch to FAAT setup (OAT= oblique Actie Tilting, FAAT= Fore Aft Active Tilting) and completely redesign it
Here's the new design.... I'm thinking of reverse molding it a making a fiberglass shell to reduce weight for more lifting capability. This design has loads of room for all sorts of fpv gear :)

http://vrwolfphoto.com/bicopter-uav2.jpg

http://vrwolfphoto.com/bicopter-uav3.jpg

http://vrwolfphoto.com/bicopter-uav4.jpg

Sirod
8th April 2012, 11:25 PM
An impression build WRWolf,

Just came across the your posting, searching if anyone have done a bicopter with
HK board now that is it readily available. I am starting a second attempt at OAT, the
first being a weak attempt using my own controller design around16F628 Microchips.
Needless to say, it was too slow for multi-rotor applications.

Could you tell me what version of firmware you are using, (KK's Tower or KKr's twincopter )?. At the moment, I have only ability to flash hex codes and I am using Minsoo Kim's XXcontrol_KR_TwinCopter_v2_5. It seems I am not able to reverse one of the servo channel (for pitch/jaw control). I am thinking I may have missed
some set up instructions.

Appreciate any input from you.

Sirod

Scotttu
8th April 2012, 11:30 PM
NOW you guys have my attention!

I rather liked the "Helicopters" in Avastar the movie - and someone out there built a foamy and flew it (Non FPV I believe).

This is cool.

I will be monitoring this thread!

VRWolf
9th April 2012, 04:34 AM
An impression build WRWolf,

Just came across the your posting, searching if anyone have done a bicopter with
HK board now that is it readily available. I am starting a second attempt at OAT, the
first being a weak attempt using my own controller design around16F628 Microchips.
Needless to say, it was too slow for multi-rotor applications.

Could you tell me what version of firmware you are using, (KK's Tower or KKr's twincopter )?. At the moment, I have only ability to flash hex codes and I am using Minsoo Kim's XXcontrol_KR_TwinCopter_v2_5. It seems I am not able to reverse one of the servo channel (for pitch/jaw control). I am thinking I may have missed
some set up instructions.

Appreciate any input from you.

Sirod

I was using the "Twincopter v2.5" available here http://www.kkmulticopter.kr/index.html?modea=xxcontroller seemed to work fine except I got a dud hk board with a faulty pitch gyro and got a nasty wobble on the pitch axis no matter what the gain was at.... but for the price of those boards it's no real loss, lol! I also need to upgrade to high torque-high speed servos to keep up with the gyros. when used the kkmulticopter flash tool it has a servo reverse version too. I'm kinda thinking of trying hk's v3 board now that it just came out. I'm also considering trying a Wii setup with accelerometer (motion plus-and wii nunchuck) I still haven't sourced firmware for it but I have seen bicopters fly quite well on the Wii setup.
It has proven quite a challenge, not exactly a well traveled path when compared to helis, quads and hex's.... I haven't worked on it for a bit, kind of been side tracked with my current fixed wing, lol.
probably get the v3 board in my next order from hk which should be soon then start playing around with it again, want to make this design stronger too... perhaps a fiberglass shell. though I think it turned out ok for a prototype

Sirod
9th April 2012, 06:34 AM
Thanks for the quick reply !

Yes, I am now using the same twincopter V2.5, normal and reversed.
Not exactly sure what is the real fix, because, I replaced one of the servos
along the way. Now they appear to be working ie. same direction in pitch and anti-phase in yaw. I thought servos of the same brand always come in standardised one direction.

Speaking of servos, I am thinking of using higher torque metal gear if/when this of mine prototype works.

Thanks again, I will let you know how my build goes.

Sirod