Nimbus Tricopter VTOL

yes i think ur right, flying in the hot tropical part of this earth make it more fragile… for hobbywing xrotor 40a

Hi Greg: i got a Speed sensor in but it only has a 3 wire servo connection the one i bought says for apm2.6 & pixhawk so would you know what aux port i need to plug it into or doesn’t it matter and does the pixhawk know that it’s a speed sensor or do i need a different sensor,i’m still waiting on 16.5.5 props to try a Q Stab Test

Hi Butch,

What you have is called an Analog Airspeed sensor and it will work fine on the Pixhawk. I just installed one on my FireFLY6 VTOL. Connect it to the Analog to Digital converter 6.6v port in the corner next to the I2C port.

In the link above, read the paragraph called, “For the Pixhawk” in the " PX4/Pixhawk Analog Airspeed Pin and Wiring" section. Pixhawk pinouts are here.

Good luck!

Hi Greg: i got the rear set 16.5.5 CF Props in and i’ve been checking everything all over and i’m wondering maybe about why i have no rudder movement in no Q-modes only in FBWA and i got lots of up but only a few deg on down and the same thing when moving the Elev stick 20 deg up but only a few deg down it hardly moves and the elev stick doesn’t move while in FBWA? i’m scared to try Q-Stab and Q-Hover i hoping that this is whats supposed to happen using this Q modes i’m used to moving all my sticks and see movement to make sure everything works thanks B.K

Butch,

You certainly tackled a more complex project for your entry into VTOL but I think that you are ready to try a test hover. On your first test, simply use QSTABILIZE mode and see if you can hover a few feet off the ground. Keep the plane in front of you with the tail facing you so the right stick is left for left, right for right, up for forward, and back for backwards.

Once you have verified that is mode hovers the Nimbus, then try QHOVER which holds the altitude when the stick is in the middle but also desensitizes the throttle so you need much more to make it go up or down. Lastly, test QLOITER mode which adds GPS and tests your compass calibration.

It would also be wise to have plenty of room for your initial tests…like a softer mowed grass field.

Good luck!

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Hi Greg: Thank You for the reply,I’m still need the 13.8 props unless it’s ok to use these CF 13.5.5 props i have from one of my drones to do the Q-Stab then the Q-Hover test and it’s really been windy down here and i want a wind free test site on my first go around (nervous) Lol heck i don’t fly any of my drones in the wind when i’m testing.So is their a site that tells you how each of the FM’s how they fly and what you need to do to use them? when i fly my drone start out in manual or Stabilize then i get it up and can fly it around manually unless i put it in one of the flight modes like loiter or pos hold etc ,and the throttle has to be in the middle but i can yaw it, raise or lower it and move it L-R- F or back as long as the throttle is in the center is this the same as this VTOL Fmodes? I have watched your Video and goggled but no body actually describes what or why their doing it and how it should respond and then what control do you have in any of these modes. I was also really liking that Horus X10s? transmitter and thinking about it alot! and what you said it could do but i don’t know how to code or do that high tech stuff, but i’m still thinking.Thanks B.K

I don’t know what you are asking here.

The APM Wiki has a brief section called, Flying a QuadPlane, that may help. Having both copter and plane flying experience is a prerequisite. Once, you have passed your hover tests, the initial transition flights should only use the FBWA mode in a wide open area as you get used to the lack of normal plane control. In this manner, if you get into trouble, your emergency bailout mode is QSTABILIZE or QHOVER or QLOITER. The amount of control offered by the sticks in forward flight can be adjusted by the MIXING_GAIN parameter which I generally crank up to 1.0.

Cheers!

Hi Greg and any One in this Group:I received my 13 inch props in the mail and i tried them on and holy cow if the props go back they will hit the wing!! so is their a setting to be able to prevent this.Thanks B.K

Yes, the settings mentioned above will prevent this.

  • SERVO9_MAX
  • SERVO9_MIN
  • SERVO10_MAX
  • SERVO10_MIN
  • Q_TILT_YAW_ANGLE

Ok, I just finished moving to a new state! Got almost everything back up and running now. Same problem:

I put her into QStabilize mode, up the throttle, she pops up, hovers in place and is responsive to all commands.

I then land her while in QStabilize mode by putting the throttle to about 39%. She taps the ground and then lowers her throttle automatically.

But she never stops spinning! She does not respond to a disarm command from the transmitter (ARMING_RUDDER is now at 2).

I can even take her back off if I up the throttle.

I have to (dangerously) disconnect the battery manually OR I can hit the arm/disarm button from mission planner to get her to shut off.

All other behavior is as expected.

I have another VTOL that does not have this behavior.

Any ideas?

Chad,

To get your props to stop in QSTABILIZE mode at minimum throttle, set Q_M_SPIN_ARM to 0.0

I am not familiar with a “disarm command” so try moving the yaw stick to the far left. Are you using yaw to arm and disarm?

For the disarm issue, try re-calibrating your radio in Mission Planner. I suspect that the yaw movement to the left is not being seen as far enough. Calibrating the radio will align the transmitter stick endpoints with the SERVOx settings.

Good luck!

So I’ve dug deeper Greg,

It’s not a calibration issue, I re-calibrated and verified the PWM numbers, it’s all good.

The disarm command I was referring to is the one under Flight Data, Actions tab, look at the bottom right side of the green buttons and there is one called ARM/DISARM, that one works.

The aircraft should disarm if I hold the rudder to the left for 2 seconds while at zero throttle but it does not, I think this is a known issue: https://github.com/ArduPilot/ardupilot/issues/8411

I can put the Q_M_SPIN_ARM to 0.0 but I feel that that’s a work around and since the aircraft is not disarmed there is a safety issue, plus I cannot use the kill switch on the aircraft to disarm it as only the GCS’s ARM/DISARM button will work.

I’m still trying to figure this one out.

One clue:

"### liang-tang commented on May 16, 2018

it just disarm automatically in AUTO mode(RTL,LAND…)"

So maybe I should rig a switch to put it in land mode as I already have QRTL…

Still thinking on it.

Ok, I found a good method for me.

Through my Futaba transmitter (T10CAG), I made a mixing function.

Switch E is a two position switch
Switch G is a three position switch

  1. If Switch E is in the up position then Switch G is QLoiter, FBWA, RTL(plane then switches itself to QRTL as per the Q_RTL_MODE parameter)
  2. If Switch E is in the down position then Switch G is QLand, QLand, QLand

So, in any event, with the aircraft flying or landed if I throw Switch E into the down position the aircraft will either land like a multirotor (which is the way I want it) OR if it is already on the ground and the damn thing wont disarm then the QLand mode will detect a zero throttle and/or a no decent rate and it should disarm.

Here is a possible alternate I’d like ya’lls opinion on:

Switch E is a two position switch
Switch G is a three position switch

  1. If Switch E is in the up position then Switch G is QLoiter, FBWA, RTL(plane circles the Launch Point)
  2. If Switch E is in the down position then Switch G is QRTL, QRTL, QRTL

In this configuration, if the aircraft is in flight then putting Switch E in the down position will cause the bird to stop what it’s doing, transition to forward flight, get close and then land as a multirotor. If the bird is on the ground and wont disarm then the QRTL will see that its altitude is below 10m (barring extreme barometer drift) then flow into a QLand mode which will detect a zero throttle and/or a no decent rate and it should disarm.

What are the flaws in the two options?

Nimbus VTOL V1.4.param (17.1 KB)

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I did some more testing this morning, here is some data that might help others:

14minute 56second hover under these conditions:
wind <2mph
10aH 10C battery at 25.11V, weight of 2.65lbs
Charging the battery back up to 25.2V used 9654maH of charge
Starting hover current 33A, ending hover current @21V was 36.5A
No payload
Airframe weight is 7.51lbs without payload or battery

Nimbus VTOL V1.4.param (17.1 KB)

Here are the telem logs and .bin logs for any analysis you might want to do.
https://drive.google.com/open?id=1c8iRj9SYR93rfHJyuCXo9N31RdLAVzZF

Hi: So i went in and changed the min and max Servo 9,10 to try and get it to be at 90 deg in Q_Stab both i changed to 2050 max and 980 min like Chad’s i saved params un plugged restarted then went and looked and nothing changed i can’t get the tilt to 90 deg in Q_stab nor can i get them to 180 or point forward when i switch to FBWA any suggestions would be very helpful, right now when i start up in Q_stab the tilt motors are at 110/115 deg and in FBWA they are at 155/160 deg.Thanks

Hi: so i think i solved my prob in the previous post by after changing Params i attached the battery saved the Params again then,disconnected the Batt then disconnected MP turned off Tx turned everything back on checked the param list and that worked Now my only prob before 1st Test flight is how do i change and limit the tilt servo’s move back from hitting the wing when moving the Tx control sticks any Help is appreciated Thanks

I tweaked the high and low endpoints via mission planner servo9 and 10 until the servos visually looked correct.

When you mounted the servos you should have screwed on the control horns so that there was excess travel past the 90deg (the up position) and the 0deg (straight forward position). When you can manually move the servo motors by hand to the 0 and 90 degree positions, then use your hand to move PAST (towards the wing) another 20 degrees.

When that is done, that’s when you tweak the min and max parameters so the motor is straight up and straight forward.

You then can adjust Q_TILT_YAW_ANGLE but just as was told to me, 13deg is perfect, but you can still tweak it if you wish.

A 13 inch prop will come to within an inch of smacking the wing at Q_TILT_YAW_ANGLE = 13deg. That’s a safe distance in case the props flex in flight (and they DO FLEX).

Hi Chad,

I was out of state on vacation last weekend. Great fun and so far we are having a nice Fall season!

As for the props spinning when armed, it is a personal choice. I have some VTOLs set to spin slowly and others set to not spin. It doesn’t really matter to me. I have found that my FrSky/Yaapu telemetry setup seems to be the best because all six flight modes are on one knob (same for Taranis and Horus) and I get an Amber audible through the MavLink messages for “Transition Complete”, “Landed”, “DisArmed”, etc.

Cheers!

Hi Greg: here’s hoping you enjoyed your Fall vacation.Does this Yaapu telem setup work on a Taranis X9D + SE Tx and if so do i need to set up a mav link radio and ground Station?I guess i’ll have to check this out,oh i’m almost ready to try out a Q_Stab and hover test my front props just cleared customs import ,today i’ve installed my 2 Cameras,put together a COG stand and if and when the wind quits i’ll put everything together and give it a test when all systems are a go

Hi Butch,

Yes, the Yaapu telemetry works on the Taranis X9D and other radios (see the Wiki link). You only need to physically set up the airplane side by running a cable between the Pixhawk Telem port and the FrSky S.PORT connection of the receiver. All other setup is basically changing a Telem port setting and then loading the firmware on your transmitter.

You can read more about it below in the APM Wiki.

FrSky Telemetry