Dual-motor tailsitters

Development Team
489

Here the complete set of .STL Files and an instruction how to use it.

The 3D Print needs switch on support material and Infill 40%. Works great with PLA.
Base Units Right and Left
Base Unit L.STL (560.7 KB)
Base Unit L.STL (560.7 KB)
Motor Carriers Right and Left (according to the cable out of the motor)
Motor Carrier L long.STL (101.6 KB)
Motor Carrier R long.STL (101.6 KB)
Servo Fixations Right and Left
Servobefestigung L.STL (24.9 KB)
Servo-Fixation Right.STL (24.9 KB)
Counter Bearing for both sides
Counter Bearing.STL (32.9 KB)
Template Right and Left
Template R.STL (148.7 KB)
Template L.STL (124.5 KB)

And filnally the Instruction
Manual Tilt motor carrier.pdf (311.1 KB)

Kind regards, Otto

3 Likes
490

Hi, Tridge sent log and video of rev 8, new design, google drive, not so good, if you could take a look when you get a chance…thanks

491

https://youtu.be/L7AdyZwSeuY rev 8 video 2nd hover

1 Like
492

Again, one step ahead. And amazingly despite the “additional” 2 Servos to tilt the motors only 2 Servos in total.
I’m curious to see the plane characteristics.
Good luck

493

Today we wanted to test our first vectored tailsitter on the bench.

tailsitter.jpg1130×1280 218 KB

FC is an original pixracer with few days old master firmware installed.
After doing all calibrations and settings, we have the following issue:

In QSTABILIZE or QHOVER the highest motor PWM output is not more than 1500, in MANUAL mode PWM output is correctly as parameterized 2000.
THR_MAX is 100.
Here are the other parameters:
00000009.BIN.param (16.0 KB)

Does anyone have any idea why PWM Output in Q-Modes ist not above 1500 ?

Regards Rolf

494

looks nice!

can you post a dataflash log of trying QSTABILIZE with a range of throttles?

495

Hi Tridge,

logfile: https://www.magentacloud.de/share/ci7vxt6at6

throttleissue.JPG1349×520 110 KB

If the plane is lying on the belly, in QSTABILIZE (or QHOVER) full throttle allows the controller only to turn motor PWM (RCOUT.C5/C6) up to maximal 1400.
That is not enough to lift the planes front. In MANUAL (or FBWA) modes the engine power control works well.

As soon as I raise the plane (with the hands without props mounted) nose up, engine power works also well. As soon as the plane is lying on the belly again, motor control is too weak again (red circle in the diagram).

Thanks for the look
Rolf

496

I can confirme the issue of Rolf above with my Caipirinha.
Even worse the max Power with Ch3in 2000 flat is PWM 1220 and in Tailsitter Pos. PWM 1800
Indicated in MP on Ch5out and Ch6out.
ESC’s and Radio calibrated.

Therefore not lying on the belly but lying in the shelve.:slight_smile:

Thanks for help

497

https://youtu.be/Rm01DeAgJMI… illusion auto, hover, loiter, land

498

yey Tridge ,
you around? sent logs
Rick

499

congratulations on your first QLOITER! Looks like it did pretty well.
The attitude tracking was excellent, the EKF was happy and all the sensors look good. Very good result!
Do you think you’re ready to try forward flight on the Illusion?

500

I’ve tracked this down to the angle-boost code. If you set Q_A_ANGLE_BOOST=0 then I think you’ll find that you get the full throttle range at any angle.
The angle-boost code doesn’t really make sense for a vectored tailsitter, as it is assuming thrust is to the front of the vehicle.
Sorry for not spotting this earlier!
Cheers, Tridge

501

Thanks Tridge.
Just backyard tested and it works well :slight_smile:
(For a complete flight it is unfortunately too windy today. Hopefully tomorrow)
Regards Rolf

502

Thanks Tridge[quote=“tridge, post:499, topic:15302”]
first QLOITER! Looks like it did pretty well.
[/quote]one interesting thing I noticed is as it leaned into the breeze it would descend and move forward as opposed to manual flight , would lean and climb as more lift is generated by the wing[quote=“tridge, post:499, topic:15302”]
Do you think you’re ready to try forward flight on the Illusion?
[/quote]almost, I think I will add some vertical stabilizer area for the 1st try having had some of these stright wings yaw to vertical when rolling into a turn in forward flight

503

there may be an airflow effect with the barometer. It thought that it stayed within 40cm of the desired height, but the video shows it didn’t.

yes, good idea. We don’t have have support for differential thrust for yaw in forward flight, so it will be reliant on yaw stability of the airframe

504

great!

I look forward to it. Good luck with the flight testing!

505

we are going to need that, .01 to 5 %would probably do in my case and maybe mix with aleron/elevon

506

pull that off the shelve, sounds like Tridge fixed it !!

507

SERVO#_FUNCTION =?= RC#_FUNCTION

This conversation mentions SERVO(1-6)_FUNCTION, but I only see RC(5-9)_FUNCTION in Mission Planner 1.3.48 (Advanced Layout) with Plane 3.7.1 on a Pixhawk1.

Feels like I’m missing something pretty basic. Would you please steer me in the right direction?

I tried a couple of things:

  • Plane documentation shows SERVO#_FUNCTION, but not RC#_FUNCTION.
  • This Copter post suggests the two are synonymous.
  • Added SERVO#_FUNCTION parameters with a text editor, but Mission Planner rejected them upon trying to load the file.

Thanks in advance!

508

You have to load 3.8obeta5 firmware.