Servers by jDrones

Nimbus Tricopter VTOL

(Bobby Moser) #183


Thanks! I will give those a shot and see if I can get it all true. BTW one of my issues with the VTOL was getting telemetry from the aircraft. I was using Frsky at first but really wasn’t happy with it. Now I am looking into going with a CUAV 900mhz radio system for the telemetry. How do you like the system you are using?



(Greg Covey) #184


I’m using FrSky 2.4GHz for R/C and FrSky telemetry with the Yaapu script, and, 900MHz 3DR SiK for MavLink telemetry. Both are short range systems for local mapping. I like having the FrSky telemetry on the Taranis using the Yappu script for flying but using Mission Planner for GPS telemetry, mapping, and autonomous missions.

I think you might be using a longer range system for FPV?


(Bobby Moser) #185

Thanks again for the parameters you were on the button. I tweaked it in perfect now. Yes I am always using long range don’t think the vtol will do what my forward flying ones do but that’s okay. I am still trying to get all this mavlink telem and ardupilot stuff worked out. I use PitLab and all of it is way different.

Thanks again,


(Atico) #186

Hi Greg, Graham, Gordon

From each wing of the Nimbus we only have the signal cable for EScs and Tilt servos.

How do you connect these in the pPxhawk? Alone or accompanied with its corresponding GND cable?

Gordon, How has Foxtech connected it?

Atico from Bilbao

(Greg Covey) #187

Hi Atico,

Many of us have been using the original XUAV conversion kit diagrams below. It is part of the conversion kit directions here. We have the aileron ground connection and battery ground in each wing. The aileron signal connection gets ground on the connectors but the others (ESC and tilt rotor) get only signal connection. The ground is through the battery feed to the wing which gets connected to signal ground at the additional 6v BEC in the wing…so they are really the same ground.

(Atico) #188

Yes I know but I seem important to connect signal and ground in the rail of the pix.

(Greg Covey) #189

It is essentially already connected via the aileron ground. The Pixhawk Output and Aux ground pins are all connected together and the wing ground wires are connected together so it doesn’t matter if the connection is one pin over from an identical ground. Think of it as just a few mm long wire.


(Gordon Ottershaw) #190

Thanks for your question about wiring.

The Nimbus was just packed yesterday for shipping to the US. (Shrink-wrapped and banded.)

It will be a while (perhaps several weeks) before I can check this for you.

(Ryan) #191

Have you transitioned your nimbus yet? If so, what flight modes are you first testing transition? Do you use manual for the first transitions, then use FBWA?

What are your params? Can you share the most recent param file that you have transitioned with? I am building one now


(Greg Covey) #192

Hi Ryan,

Winter has set in and I have not transitioned my Nimbus VTOL. However, others in this thread have transitioned their models. My current .param file is posted above.

Typically, I set the following modes up on my Taranis X9D+ for a VTOL. For a plane, MANUAL is used as the emergency bailout mode, but for a VTOL, I use QSTABILIZE (or QHOVER or QLOITER) as the emergencey bailout mode since these modes have already been tested. It has been my experience with APM Plane that the vehicle trims itself in the air as long as SERVO_AUTO_TRIM is enabled and the plane has been set up properly.

  3. FBWA
  6. QRTL or AUTO

(Ryan) #193


How do you have 6 modes set up? I can only get 3 modes on my taranis X9D+… I would love to have 6 modes at a time lol

So the SERVO_AUTO_TRIM is running continuous? I don’t need to save the trims?

Thanks for all posts and help! You have been a great help!


(***) #194

I used this guide to setup logical switch functions on my taranis.
Logical Switch Functions

(Greg Covey) #195

Yes and no need to save the trims as they are auto-saved.

MRC87’s link is a good one to learn the radio feature. If you’re lazy like me, just unzip and copy my Nimbus VTOL OpenTx file below into your model list. The assumption here is that you have the 6-position knob S3 installed on your X9D+. (914 Bytes)

(Ryan) #196


Thanks for sharing your taranis file! I am going to try this out!

Is this the order you set them up in ardupilot?

  3. FBWA
  6. QRTL or AUTO
  • Ryan

(Greg Covey) #197

Yes, that is just my preference. I like to leave the “bailout” mode at one end (clockwise) of the knob turning. In this case, it is QSTABILIZE mode. For your initial flights and learning, you could put it on both ends for more safety during a panic situation. During initial hover testing (when I don’t plan to use forward flight) mode positions 3-6 all get loaded with QLOITER to test the GPS fix control and prevent an undesired transition to forward flight.

So the modes get changed in Mission Planner and the Amber sounds get changed in OpenTX Companion. If you use the Yaapu telemetry script, it has independent audibles for a confirmation that APM actually went to the desired mode.

(Chris ) #198

Hi Guys,

I hope I am asking this is the correct space…

I have built up a nimbus VTOL. all the parts were purchased under the guidance of the fox tech guys recommendations and bought from fox tech.

I am having an annoying issue on my throttle, to the point that I am too nervous to try a transition as I don’t believe there is enough power on hand to arrest a fast decent.

My throttle seems

Firstly very sluggish, if I see the VTOL is descending slightly and give more power there is a massive delay between adding throttle and actual result in the airframe gaining some altitude.

Second problem I am having is I need to hover at 3/4 throttle value and at points am giving full power to maintain a hover. Sometimes I even belly bounce as I cannot give more power to start lifting

I have 2 x 6 cell 5000 mah (so 10000 Mah total)
45c Rate
Motors and props as follows
Front 2 wing mounted Sunny Sky X4112S-9 485 kv with a wooden 13x8
Boom mounted Sunny Sky X4112s-11 400KV with a carbon fibre 1655 prop

Flying at sea level

Nimbus VTOL Throttle mid settings
(Greg Covey) #199

What flight mode are you in? I suspect you are in either QHOVER or QLOITER which has sluggish throttle. You can read about Alt. Hold throttle control here. Try testing in QSTABILIZE mode. It uses raw throttle without the BARO and GPS sensors. Hopefully, you have copter flying experience.

Can you plot the motor throttle (RCOUT) graph from one of your logs like shown above? My setup uses C5, C6, and C8 but your setup may differ. I would also recommend an ESC calibration using the procedure here. If the CAL=1 procedure doesn’t work, try the CAL=2 procedure and remember to take off the props!

What is the weight of your 10AH pack?

(Chris ) #200

Hey Greg,

Thanks for the advice, so today I tried again after some fiddling and a few ESC’ Calibrations over the weekend.

I noticed that I have far better throttle management after the ESC Calibration. however after a bit of hovering I noticed that I started with the same issues again throttle at the upper end and not as responsive. when I landed I checked the motors and were surprised how hot they were, not burn blisters hot but hot enough to raise an eyebrow.

My Plane is also no where near as locked in as I have seen in other vids where do I look to tune this? is this PID Settings…

Yes Greg I have a bit of coper experience…luckily
All up weight of the unit is 4.40kg
And pack weight is 1.419kg

(Greg Covey) #201

Hi Chris,

Your pack weight is about 0.227kg (8oz) heavier than my 1.2kg (42oz) Multistar 10AH pack. It shouldn’t cause much of an issue. I don’t know where you are located but it is winter here and I haven’t seen my motors or ESCs get hot. What ESCs are you using?

For PIDs, we are using the FoxTech V1/V2 PIDs that you can find in the posted .param files above. The thread is getting rather long so I’ll post them here again. We seem to be fine tuning the Yaw PIDs a bit from each other which is likely due to setup differences.

Look for these parameters to check against the V2 file. There is also a list of differences we found between the setups that was posted above.

Hover Modes

Forward Flight

GrahamsNimbusVTOLafterREinstall.param (17.2 KB)

GordonsV2_Nimbus_List.param (17.0 KB)

GregsNimbus1.param (17.0 KB)

(Chris ) #202

Hi Greg,

Thanks I have adjusted my pid settings to the V2 param file. I will give it a go later today and let you know how it goes.

I am in Cape Town South Africa so we enjoying lovely sunny summer weather


Chris Bews