Edf Vtol

[taileron]

Hi all,

... my EDF VTOL hovers over 4 min and flies perfect in forard aerodynamic way 10 min or more... but any attempt of a transition endet in a crash yet.
made of styrofoam and cfk

a few details:
weight 980g
thrust 1610g
wingspan 55cm
length 56cm
current-draw/Hover=40...47A
max current=82A (yes a bit too much for Kokam 3.2ah)
2 * edf 40 Feigao 12mm bl 5822 rp/v with YGE12
1 * Kontronik Fun 480-47 with Jazz 80-6-18

further infos:
http://www.taileron.de/

anyone with experience about transitions yet ???
currently I,m trying to program a 3 axis gyro that fades continously from roll to yaw stabilization on a NEC 32bit microcontroler. Especially in 45° thrust angle the gyro is the most important and in this moment the gyro axis is something in between roll and yaw .... and by the way the ground allways doesn´t draw aside ...

[Tuner]

Right ON! Nice to see some new projects.
Yet more reasons for a worm drive servo, ignore that.

I love this design. So simple and it looks durable.

Scott

[v22chap]

Taileron...welcome to the forum ,,,,great new little VTOL you have there. As tuner said ,,great to see an original design.
I use a gyro mounted on my tilt arm to control roll axis and it then follows on over into airplane mode and becomes my yaw axis ,,but I have a different problem to over come with my V-22 design and I really don't think this setup would help yours to much.
I would think that with your setup you could do as VTOLman did with his and just gain altitude and then go right on into forward flight without staying in the 45 degree postion very long.With your light weight and wingloading it shouldn't take much airspeed to become wingborne.

What does it seem to do when attempting forward conversion?? Roll over and spiral to the ground??
That is what I am guessing happens and if it is ,,you might try disconnecting the front and rear motors ,,so that the front only moves into conversion mode and the back two stay in the heli mode a little longer to control the roll axis until you become wingborne and then rotate them to horizontal position all at once to help in forward flight.
Joe orlando is working on an onboard controller that he hopes to do the roll / yaw fade for VTOL guys ,,but so far I haven't heard anything from him on that mode to his TH-2 GP mixer board.
Good luck on your wonderful project and keep us updated with pix and videos.
Larry

[taileron]

... from hover to 45 degrees the gyroscopic effect results an extreme roll to the left above 45 degrees more and more yaw so the plane does a kind of rool to the right in combination with a turn from forward to backward and the result is a aerodynamik stall or something like that resulting in an absolutely reliable crash ....even when the plane has climbed very much by hovering. It goes into a kind of tailspin with no way to come int forward flight anymore. My hope is to have more gyro stabilisation on both roll and yaw while this dangerous moment of about 45 degrees of thrust. By turning the front edf to forward flight the thrust fades more to center of gravity thus it´s neccessary to reduce thrust of the rear ones to avoid dropping to the nose.
The 3 axis-mixer-gyro-board we´re currently try to program hopefully will lower this effect.

[v22chap]

That is what I though .. as even my project did about the same thing until I got the gyro to help out.Didn't think about the lack of frontal lift after moving that fan to the 45 degree point . I just assumed that since it was the bigger fan it would grab enough air quick enough to pull it on into forward flight without loosing to much altitude before it became wingborne and you could then pull all of them over to airplane mode.

Good luck on the programing of the 3 axis gyro .. sounds like that is your only hope right now.. good luck and as always have a lot of fun while doing it and keep us posted with updates :D

[Tuner]

Another Idea is to take it up to an altitude and then cut power rotate the motors and by the time they are rotated the plane will be falling or starting to fall and just add power and it will basicly just do a stall and recover if it happens fast enough you might not even loose altitude.

Or Try transitioning the main fan First leaving the rear fans for roll control to cancel the gyro forces of the main fan. Only once the plane is in forward flight rotate the rear fans horizantal.

What 3 axis Gyro mixer board are you using. I have been looking for a simple 3 axis gyro setup.


Scott

[taileron]

I´ll do my own mixerboard the weight might be about 10g with 3 AD XRS300 and one 32bit NEC V850 CPU currently all mixing is done by two ACT DSL6 receivers (each servo out has 4 mix sources) so it has 12 different servo channels. Two gyros (ACT Pico SMM) are processing the mixed signals for the two rear edfs positionned 45° to the forward axis and they have to be switched off at more than 40° thrust vector.
Accurate hovering above the head is just impossible cause the reaction of the plane is visble much too late to have enough control.