Re: Asymmetric Tricopter Build (Half Step to Bicopter)
Patrick, Fri Nov 02 2012, 11:50PM

2.) Previous Builds/lessons learned



tricopter (old) Flight proven...

wheighs 1.322kg, flies for 4-5 minutes on 3S (11.1V, 2200mAh).

Re: Asymmetric Tricopter Build (Half Step to Bicopter)
Patrick, Fri Nov 02 2012, 11:51PM

3.) Operation - Flight.

Re: Asymmetric Tricopter Build (Half Step to Bicopter)
Patrick, Fri Nov 02 2012, 11:53PM

4.) PID tuning and Sensory Aquisition....

Re: Asymmetric Tricopter Build (Half Step to Bicopter)
Patrick, Fri Nov 02 2012, 11:53PM

5.) Supporting Souces and threads....

Re: Asymmetric Tricopter Build (Half Step to Bicopter)
Patrick, Sat Nov 03 2012, 01:19AM

6.) Current Build Components.




Airframe (S-2, CF-AS4, Epoxy and Balsa)
Using a space heater and hoping it cures right...


Ducts = 250g
airframe = 314g
motors = 156g
battery = 176g
electronics = 80g
mechanics = 140g
camera pan and tilit = 100g
lidar = 120g
-----------------------------------
total = 1336g
-1500g
-----------------------------------
=164g margin

Wens 14, 2012 HexTronic Motors:

DT 750's!


Long ass shaft to be cut down soon.



Standard super-mag seen here, much better than the soft mags on the E-Flites...



aluminum bell with stainless band.

Ive got motors!!!

Re: Asymmetric Tricopter Build (Half Step to Bicopter)
Patrick, Mon Nov 05 2012, 07:46AM

Updated Build Pics...

Re: Asymmetric Tricopter Build (Half Step to Bicopter)
Steve Conner, Mon Nov 05 2012, 10:18PM

Can't you add one more gram to get it to 1337?

Re: Asymmetric Tricopter Build (Half Step to Bicopter)
Patrick, Tue Nov 06 2012, 02:19AM

what significance does 1337 have?

Re: Asymmetric Tricopter Build (Half Step to Bicopter)
Mattski, Tue Nov 06 2012, 03:28AM

It's "Leet": LMGTFY

So what are the tradeoffs of a quadcopter versus a tricopter? If I'm understanding tri-copters appropriately from a quick googling, the two main fans provide lift and cancel each other's angular moments. Is the tail fan running continuously? It sounds like it tilts to provide yaw maneuvering. and I'm guessing it also provides pitch motion by varying its thrust. Do you worry about the angular moment of the tail fan?

Re: Asymmetric Tricopter Build (Half Step to Bicopter)
Ben Solon, Tue Nov 06 2012, 03:56AM


Yes, it has to in order to cancel the torque of it's weight and stabilize the craft.


Correct. They typically use a servo to rotate the segment connected to the prop


It's negligible for the most part, but any rotational motion can be cancelled simply by using it's function. Provide a thrust vector that's rotational component is equal and opposite to the force exerted by the tip of the prop.

Re: Asymmetric Tricopter Build (Half Step to Bicopter)
Patrick, Tue Nov 06 2012, 03:57AM

1337 zoooom --- right over my head! DUH.


the advantage of the tricopter is:

(the main advantage is half the ESCs, props and motors to break)

-Field of vision for lidar (dont have to look through props)
-Better balance and i have rear and fore access for picking things up.
-with only two large fans theres half as much to break as a quad, the tail fan has taken 60 foot falls tail first
and not broken.
-the bicopter needs much heavier tilt mechanics than the single tail rotor.
-the two large front fans mean i can use bigger props for greater effciency.

the real purpose of the tail rotor is to generate the pitch authority, something the Bicopter must generate thjrough gyro-precession.

ps im druNk../

Re: Asymmetric Tricopter Build (Half Step to Bicopter)
Patrick, Sun Nov 11 2012, 04:33AM

Ok update and pics...

Re: Asymmetric Tricopter Build (Half Step to Bicopter)
Josh Campbell, Sun Nov 11 2012, 07:00PM

Looking good!
Where is the CG on your old Tricopter?

Re: Asymmetric Tricopter Build (Half Step to Bicopter)
Patrick, Mon Nov 12 2012, 12:30AM

Every flight was made with the CG about 0.9 to 1.2 inhces abaft of the CL, which was deliberate on my part, yet unwise... i wanted to make the machine balanced on the forward larger props. much like a Bicopter would be. this one will have its CG near teh orange battery.

the tail rotor, on several occasions, stopped spinning and the tri flipped and crashed.... (due entirely to the CG and GL being to close without suffcient throttle resolution.)

Re: Asymmetric Tricopter Build (Half Step to Bicopter)
Patrick, Wed Nov 14 2012, 10:15PM

Updating #6, Look above.

Re: Asymmetric Tricopter Build (Half Step to Bicopter)
Patrick, Sat Nov 17 2012, 08:04AM

Motor Mounts:



Templates, on 0.200" Bass wood.



Center relieved by 0.080" due to cheap chinese motors having an unpreditcable shaft length.



3 triganol planar screw pattern for 4-40 screws.



4-40 screws epoxied and ground flush.



Screws!



S-2 fiberglass coated to prevent splitting in crashes and to resist age and vibration weakness.