14 June, 2019 at 16:43 #62511
Well, it might have been a crash too, which I had quite a few as I’m still a beginner… 😉14 June, 2019 at 17:34 #62512
Hey, I’ve broken plenty of them, too. In fact my LR was grounded the first week I got it while I was waiting for new gears. I usually break the smaller brass ones though (and usually the same one), I’ve never broken an output shaft (aluminum or steel).14 June, 2019 at 17:39 #62513
Interesting, that the more rigid ones collapse in your setup. Nevertheless I got some spares right now…14 June, 2019 at 17:51 #62514
Maybe not to dRonin related question, but kinda sorta.
The Kakute F4 V2 FC seems to be a popular board for the Tricopter LR. It only has four motor outputs andusing the LED (I think) output for the tail servo. I’ve been seeing/reading on PWM Timers and how to assign/remap them. I understand you can’t mix same timer functions, i.e. if there are four motor outputs on TIM1, you can’t assign three of them to motors and one to a servo; however, if three of the PWM timers are on TIM1 and the fourth is on TIM3 then the TIM1 outputs can be assigned to motors and the TIM3 could be assigned to a servo.
Now the question. How can I find the timer assignments for the Kakute F4 V2 board? I’ve not found it in Holybro documentation nor google searches. Is there another (easy) way of finding the TIMers and the ports they are associated to? I’m sure the Kakute F4 LED output must be on a separate timer. I’m curious if the four motor outputs are using the same Timer, just different channels and if it’s possible to assign any for other functions.14 June, 2019 at 17:54 #62515
Smaller teeth. Sort of makes sense to me. I also have bent the little shafts a few times, but the only way to replace those is to replace the servo so I usually get them as straight as I can with pliers. So far that has worked out.14 June, 2019 at 17:57 #62516
On a side note…I’ve had nothing but issues with my Tricopter LR and vibrations…both audible and in the video feed. I’ve checked the balance on the props, Emax 2207 1600kv motor bells, and props and bells mated together. Everything looks good. Our of desperation I installed some old Sunnysky 2208 1260kv motors. They ‘sound’ like they are running smoother than the Emax motors. A backyard hover test shows they will hover the Tri LR on 3S at 1/2 thorttle with the 8″ props…but I’m sure would be better on 4S. Of course it’s forward flight performance that will determine if the motor swap does/doesn’t effect the vibration issues. I’m hoping it does as I like how the Tri LR flies. It’s just not worth flying if the video (feed and recording) are shakey as ‘ell.14 June, 2019 at 18:05 #62517
“How can I find the timer assignments for the Kakute F4 V2 board?”
Here’s the stock (not functional for tricopter) channel/timer assignments from BetaFlight target.c source file:
DEF_TIM(TIM3, CH3, PB0, TIM_USE_MOTOR, 0, 0), // S1_OUT – DMA1_ST7
DEF_TIM(TIM3, CH4, PB1, TIM_USE_MOTOR, 0, 0), // S2_OUT – DMA1_ST2
DEF_TIM(TIM2, CH4, PA3, TIM_USE_MOTOR, 0, 1), // S3_OUT – DMA1_ST6
DEF_TIM(TIM2, CH3, PA2, TIM_USE_MOTOR, 0, 0), // S4_OUT – DMA1_ST1
DEF_TIM(TIM8, CH3, PC8, TIM_USE_LED, 0, 0), // LED_STRIP – DMA2_ST220 June, 2019 at 11:58 #62609
@vantasstic Try using wooden props or at least a different brand and see if the issue goes away. Maybe your props are hitting resonance when you are flying. Changing to another type of prop should shift that frequency elsewhere (if that’s the problem). Worth a shot and an easy change to see if it has an effect.20 June, 2019 at 18:56 #62613
@billyd. I submitted a service ticket with RCExplorer on the Tricopter LR vibration issues. David recommended reducing the Roll/Pitch PIDs, especially the D-term to see it that reduceds the ‘noises. You had a smooth flying frame. Do you mind sharing your current PIDs for comparison purposes?
For me, I swapped out the recommended Emax motors for some used Sunnysky 22018 1260kv motors. I’ve flown it with both HQ 8×4.5 and APC 8×4.5 props. The oscillation sound is significantly reduced. The FPV camera still shakes in forward flight though. It’s smooth in hover and slow speed, but as soon as I tilt if for some good forward flight the shakes set in. I’m going to try a different HD and FPV camera mount on my next flying session. I like how the Tri LR feels in flight, but seeing nothing buth camera shakes in the FPV make it non-enjoyable to fly.
FWIW, I’ve used both Betaflight and dRonin firmware in my Tri LR. dRonin flies it the best, but Betaflight has a better OSD and GPS only RTH capability. I’m back on dRonin now. I just need to work out why the frame is vibrating in forward flight. I’m leaning towards the arms being to thin and flexing/twisting in flight. I’ll post a video of my last test flight. I just need to edit it to keep it ‘short’.20 June, 2019 at 19:27 #62614
Here’s the DVR recording on my last flight of the Tricopter LR, dRonin firmware, Sunnysky 22-8 1260kv motors, 4S, APC 8×4.5 props. No sound but you should be able to see smoother video at hover/slow flights, then amplifying shakes in forward flight. The shakes in my goggles (Fatshark Transformers) is more pronounced than what the DVR shows.
Video from my buddy’s Tricopter LR, dRonin firmware, Emax 2207 1600kv motors, HQ 8×5 props, 3S. His has sound so yo ucan here the frame vibrations in forward flight. FWIW, my frame with the Emax motors sounded about twice as bad as his.
Thoughts? Maybe PID adjustments, frame/motor/prop issues? Props on all rigs were verified and reverified as balanced.20 June, 2019 at 19:34 #62615
I would say it’s your pids. Rerun autotune and then for YAW reduce the I term (divide it by 10) and then lower the P term about 20 to 30 % Cut the D term in half or more.
If it still does it try lowering the the pids on pitch and roll too but not as much. Maybe 10% at a time. That’s my guess.
Edit: The second video sounds like bad bearings. Or perhaps the tail assembly isn’t tight enough with the tie wraps? Something is rattling and I am not convinced it is the frame. I didn’t use the supplied tie wraps I used much heavier tie wraps and “stood” on my pliers when tightening them on the tail servo.20 June, 2019 at 19:37 #62616
I agree. This behavior is what I saw on mine when I used the janky AutoTune yaw values. Sudden throttle punches made it way worse. If I flew slow and very gentle it was kinda like the second video. The funny thing is I put in your values and it flew almost perfect…20 June, 2019 at 19:40 #62617
Can you guys post your PIDs to compare against? We’ve tried manual in-flight tuning and kept what seemed good. Thanks.20 June, 2019 at 19:42 #62618
I just finished putting mine back together last night (my kakute went kaput!) and it’s ready for maiden this afternoon. I hope I’ll have it dialed in tonight or tomorrow to post them. Of course I am using an enormous battery so the pids will likely be quite different.20 June, 2019 at 19:51 #62619
@jihlein can you explain return to home behavior in your latest firmware? What altitude does it use and can it be set to something specific? I assume if I engage RTH it will go full auto and I will no longer have control correct? I am trying to set up failsafe on my LRS and I need to know if I have to input a throttle amount as part of the failsafe when RTH is enabled. My LRS supplies the necessary signal to the controller in a failsafe situation so the controller never knows it’s lost contact with the tx. I can set any channels to any value I want in a failsafe situation. So normally I just engage RTH and I don’t have to worry about anything else.
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