Greg,
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!
Ryan
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+.
TaranisNimbusVTOL.zip (914 Bytes)
Greg,
Thanks for sharing your taranis file! I am going to try this out!
Is this the order you set them up in ardupilot?
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.
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
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?
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
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
Q_A_RAT_PIT_xx
Q_A_RAT_RLL_xx
Q_A_RAT_YAW_xx
Forward Flight
PTCH2SRV_xx
RLL2SRV_xx
YAW2SRV_xx
GrahamsNimbusVTOLafterREinstall.param (17.2 KB)
GordonsV2_Nimbus_List.param (17.0 KB)
GregsNimbus1.param (17.0 KB)
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
Regards
Chris Bews
Greg,
When I am trying to use QLoiter it is drifting and sort of toilet bowling… I have done multiple compass calibrations, and it hovers perfect in Qstabilize!!! What do i need to look at to fix this? What can I look at in my log? I want to transition asap, but need to get QLoiter working… Any ideas?
Ryan
Ryan,
You can check the number of satellites and hdop reading. You want more than 10 satellites and an hdop reading of less than 2, preferably closer to 1. You can also post a log (.bin file) for us to look at. The Wiki section below has some good information. Where did you mount your compass?
…Also look at where your power wires run, if they’re under the Pixhawk then that could be the cause. And keep the compass away from the battery.
I had to move our compass right to the back of the fuselage only then did the compass issues go away.
Hi Guy,
Thanks again for the advice.
good news and bad news.
Good news my nimbus is a fair bit more locked in after updating the PID Settings I got from you guys.
Bad news this just highlights my throttle issue more…still not getting enough power to maintain a level head-height hover…I will pop fox tech an email asking for some guidance on the issue
Regards
Chris
Graham,
I put it in the same spot like you described, and it seems locked in! I also cleaned up the power wiring underneath in the fuse so that probably helped as well… I flew it today and had GPS status 4 and 18 sats… Im using the HERE 2 module. It did much better today, felt very locked in!
Only other question I had was, when I take off and get half a meter off the ground the yaw hops a little… It still does this after I moved the GPS/Compass and did a calibration. It’s very slight, but it never does it again after that one time! Its only at take off… I will look into it more, but didnt know if you guys had seen this.
Ryan
Ryan,
I have seen that on several of my VTOLs. Not sure if it is ground effect or something else. I usually just rudder it back over to where I want it and it seems fine.
Chris,
If you could post a log from that test, we might be able to spot something.
Cheers!
I suspect that’s an EKF switch over, seen it too.
Anyone on here have a list of tuning parameters for transition? I looked on the tilt-rotor page for it specific to tilt-rotors… haven’t found much… I think we should make a master list of what parameters do what for the transition and how you can fine tune it! Any thoughts guys?
Ryan
Can’t hurt so I’ll start. The numbers for each parameter are from Gordon’s V2 file.
ARSPD_FBW_MIN,14 (The ARSPD_FBW_MIN is required to go beyond Q_TILT_MAX and complete the transition.)
Q_TILT_MAX,45 (This is the maximum angle of the tiltable motors at which multicopter control will be enabled. Beyond this angle the plane will fly solely as a fixed wing aircraft and the motors will tilt to their maximum angle at the TILT_RATE)
Q_TILT_RATE_DN,50 (This is the maximum speed at which the motor angle will change for a tiltrotor when moving from hover to forward flight. When this is zero the Q_TILT_RATE_UP value is used.)
Q_TILT_RATE_UP,200 (This is the maximum speed at which the motor angle will change for a tiltrotor when moving from forward flight to hover)
Q_TRANSITION_MS,3000 (Transition time in milliseconds after minimum airspeed is reached)
where x is the tilt rotor(s), determines motor up or down position:
SERVOx_MAX (maximum PWM pulse width in microseconds)
SERVOx_MIN (minimum PWM pulse width in microseconds)
Hey LiquidForce, check to make sure your props are not mounted upside down. You might also have a loose magnet in a motor. I know you already calibrated your ESCs but do it again and check to make sure your transmitter doesn’t have a bias (trim on transmitter is ZERO). Check prop balance. Check wiring for nicks. Double check that you have the correct prop diameter and pitches. Check that the nuts holding the props onto the motor are tight and torqued properly. Smell the motors, if you smell an acrid odor then the winding coating has broken down and you must replace the motor. Check that the motors are firmly mounted as an odd angle during use will scew a lot of performance. Spin the motors with your finger (power not applied anywhere in the system) and put your ear to it, if you hear clicks then you might have a bad bearing, unseated magnets in the motor bell or a misaligned shaft. Most likely though, if all of those are correct then you have a bad parameter somewhere.
If those fail, use a sledgehammer until nothing works, that’ll fix the problem.