Servers by jDrones

Dual-motor tailsitters

(tridge) #443

great! Welcome back :slight_smile:

(tridge) #444

really nice! Needs a lot of tuning obviously, but great to see such a simple TVBS.
Why such large elevons? I would have thought with the vectoring that you wouldn’t need much more than an inch or so

(lorbass) #445


Thank you for the mentally and technical support

(tridge) #446

what a great concept!
Now of course I’m trying to think about how to fly that with ArduPilot.
First step would be some EKF work so the state estimation doesn’t get dizzy in hover. I’m sure Paul could manage that. Knowing the exact sensor lag will be critical.
The hover should be doable using a rotating AHRS_View.
The control frequencies will be interesting - really low frequency for stability in hover, similar to a helicopter.
It would be good to create a FlightAxis model of this.
This type of config should have a high degree of natural stability. A friend of mine in CanberraUAV (Ryan) built a similar twist wing aircraft for his thesis and managed to fly it without an autopilot at all. It was naturally stable in hover with two nitro motors on the wings.

(lorbass) #447

I’m shure you will manage this.
But another chalenge will be the self finding landing pod.
If this fails, the whole flyer will be damaged by the hight dynamic energy of the rotating wings.

(lorbass) #448

I started to setup the vectored reading back 250 posts to finde how to connect and how to set the params.
The only information I could find, are the logs from kd0aij. (20.bin,…)
But not shure what typ of aircraft (tailsitter or vectored) they concerne.
And there e.g.Log 20.bin Servo1_Function =4, Servo2_Function=19, Servo3_Function=4 and Servo4_Function=0
Servo3 the same as Servo 1, Servo 4 no Function(0)
Did I miss some infos?

( research air) #449

My own, using F1 and F3 processors and mux to transition, small and light but not as talented as pix.In my quest to shrink I went to 0201 components, not easy to work with ! Now I think building a pix type specifically for small tvbs…

( research air) #450

my thinking is… 1) trying to sqeeze a little more wing area to make up for added weight,2) programmable servos can ajust , 3) yaw control force top and bottom of wing 4) can easy cut back area, foam board alerons glued on

( research air) #451

if part ,wing section rotated to simplify I think would work and make hover useful and landing doable

( research air) #452

FYI stryker design flaw ? my board design flaw ? when below 45 deg from vert. interaction of roll and yaw unmanagable does the dance( see video) not able to find way to ajust out? any ideas ?also little windy here ,stryker hard to fly ,nose down to compensate for wind climbs like crazy, watch out, need room !

(tridge) #453

any log files? Is this running ArduPilot?

( research air) #454

( research air) #455

got any pics?sounds wild, love to see it

(kd0aij) #456

@lorbass Channels 3 and 4 are unused on my Stryker.

I’m currently using the newer left/right elevon functions on channels 1 and 2:
SERVO1_MAX 1900.000000
SERVO1_MIN 1300.000000
SERVO1_TRIM 1500.000000

SERVO2_MAX 1900.000000
SERVO2_MIN 1300.000000
SERVO2_TRIM 1500.000000

ESCs are on channels 5 and 6:
SERVO5_MAX 2000.000000
SERVO5_MIN 1000.000000
SERVO5_TRIM 1000.000000

SERVO6_MAX 2000.000000
SERVO6_MIN 1000.000000
SERVO6_TRIM 1000.000000

(kd0aij) #457

Another must-build configuration!
Just need one of these on the tail for landings :slight_smile:

( research air) #458

OK ! how much ? so you think it’s not a belly sitter any more,… a tailbelly sitter( TVTBS)

(lorbass) #459

Thanks for the detailed Params.
What is new with Function 77/78 compared to the “original” Function 4/19 I used?

(lorbass) #460

Are this params in your post 184 still valid?
And are Function 77/78 for Servo 1/2 also for the vectored valid as kd0aij discribed in poste 453?

(kd0aij) #461

The new function doesn’t use the software mixer (param elevon_output is ignored) and it respects the PWM min/max limits for the selected elevon channels. This lets you adjust throws to avoid binding. You just need to set the channel reverse parameters correctly to get the elevons working properly. See:

(lorbass) #462

Thank you for your explanation.