(11-Dec-2021, 11:30 PM)hawk01 Wrote: i have read a lot about “tuning” from many advocates and some who would rather fly and not mess with it, can anyone point me towards the quick and dirty “quad tuning 101 for dummies” if there is such a thing. while there are many to be found in YT videos, i would rather get info from the folks who are into the hobby who would swear by it.

on the get go, my looming fear of messing with PIDs among others is that i may end up with a F%@€D up quad in my lame efforts to tune one! i believe after learning how to fiddle with rates, expo then a thorough understanding of PIDs may be next thing to pursue.

To tune using blackbox data, see Ronin's guide here -> https://intofpv.com/t-guide-ronin-s-quad...guide-v2-4

To tune by "feel" without using blackbox data, have a watch of the following video which is probably one of the best tutorials out there that I know of...

Worst case scenario, reflash to stock (after you make a “diff -all”) if you feel you have messed anything up. You can then load the parts for your ports and such and it will be back to the initial settings. There is no easy way I have found, just have to try…but honestly, just fly it stock for a while and see how it works for you before you change anything in the PID’s. Rates are about all I change for the first week after a build as I have expectations built up over years of flying. PID tuning comes only to address things that I feel can be improved to my personal tastes.

I personally do not tune quads and just stick to UAVTech presets.

Each one of my quads has a different flight feel which is why I enjoy them.

I prefer to spend time on the sticks and adjust as I go along.

One thing with tuning is that you don’t want it super tight. If you tune your brand new quad to the edge and broke a prop mid flight you can start to get hot motors or even burn a motor.

Albert Kim did a video explaining most manufacturers tune the quad for not how it will fly new but rather with beat up props or broken frame etc:

another bucket load to absorb here! the albert kim video piqued my interest as it does make perfect sense in that perspective. i anticipate the stock crux 3 will be enough to keep my attention as stick time will dictate how i may want to “tune” it. you have all been most helpful in all regards. my journey into this hobby is just starting and this old dog has to learn new tricks! cheers!

newbie flight report:

today i just received the happymodel crux3 which took a solid 20 days to arrive due to the holidays. here’s an outline of my observations, thoughts and initial impressions:

1. it came flashed with BF 4.2.2 which is good enough so i skipped updating the firmware to the latest release. strangely though it did not bind typing bind_rx_spi on the CLI which i tried twice, both attempts resulting in a RED error message in the field. so i just tapped the bind button.

2. i saved both “dump” and “diff all” just to be safe. forgot which one is the more important file when doing major reformat.

3. there is a component soldered parallel with the power leads on the FC board aside from the usual capacitor on the XT30 connector. this thing is huge and shaped like a barrel. it almost consumes the entire void between the camera pcb and rear canopy wall. i think it may affect camera tilt increase since it is hugging closely to the camera board. i shall try to shoot photos in the morning for a better view. hoping anyone who recently purchased the crux3 could chime in on the purpose of this thing.

4. i applied throttle curve with 80% max output for the initial outdoor flights due to the startling indoor hover which almost had the quad smack against the ceiling as i forgot to edit the throttle curve i was using on the moblite7.

5. oh and the buzzer feature is excellent! unlike the moblite7 this one is pretty loud enough to be heard above the noise floor on where i fly.

6. also on power up when you plug in the lipo you hear the usual intialization chimes but if you arm too soon, it does not arm. so after plugging in, it takes a few more seconds after the initial chime for three consecutive chimes to know that you are ready to arm. very different from the moblite7 initialization.

at reduced output i was cruising (quite fast!) at barely 25% throttle in windy conditions. any increase i make has it easily climbing and gaining more speed. this thing is an absolute rocket on 2S even with reduced max output. i suppose due to the new 2S packs or the thing is just very light. it is also way smoother and almost as quiet as my whoop, no visible vibes at all in the camera feed. although it remains to be seen during sunny conditions as i tested near dusk today.

i dragged the RSSI element off the OSD bottom rendering it unseen on the maiden flight as i did not have the goggles on hand to check this when i was fiddling with the laptop. so i was unable to assess range within the confines of my field testing. overall i am extremely happy with the crux3 and hoping it will pass the hard dive tests i attempt tomorrow without any serious washout!

cheers!

crux3 newbie flight report:

the maiden flight proved uneventful. today was very exciting and perplexing to say the least. i flew a few packs on the vacant lot which is my preferred flying field. i also picked up after the crux3 decided to spin mysteriously into the ground several times. so many in fact that i could not count and only shot a few videos via DVR hoping the folks her could chime in and see what went wrong.

the configuration was the same as the maiden which encountered a single RXLOSS moment which ended in a failsafe then a crash. for additional info, i used the same GNB 2S 650mah LiHV weighing 31 grams making the AUW of approximately 72 grams. pls see the videos in its entirety so you may appreciate the incidents that occurred.

from my perspective the RSSI was decent throughout. it seemed the AIO just decided to go on vacation during the random moments it went for an unscheduled landing!

here are the youtube video links:

latest flight report:

in a few words, problem solved! let me share the embarrassing reason why the crux3 has randomly fallen out of the sky with the gyro seemingly going nuts and the OSD seemingly intermittent “now you see it, now you don’t” in the DVR footage.

i did a major inspection of the quad upon receipt. i mainly tightened all the screws in sight and the nylon nuts holding the canopy and AIO in place. not a really huge task which may account for the uneventful maiden flight.

after today’s dismal experience, i went home baffled as to why the random “death spin” moments took place. it was hard to isolate something random than to have a known issue on the get go. i took a close look at the quad when i got home to conduct what i thought may be an exercise in futility as i already did it on day one. then i saw the front screw holding the canopy/AIO board in place seemingly shorter than the other three! a closer look reveals the bottom philips countersunk head slightly protruding on the bottom of the CF frame. i pressed it up and it did have some amount of play up and down of the CF frame.

while this overlooked discrepancy may not be the sole cause of my random desth spins, might as well fix it and do another test flight. i tightened the two nylon nut spacers against the M2 philips screw until it seated properly. in doing so it is also the time i noticed that the entire AIO board is slightly tilted upwards as well due to this issue.

when everything was said and done, off to the field i went and flew through three 650mah packs without missing a single beat! now i also discovered the crux3 can easily cruise for a boring 15 minutes under barely quarter throttle position! so a happy ending nonetheless!

whew!

as a follow up a few queries come to mind after fixing the suspect loose AIO bolt:

1. just how sensitive is the AIO board to vibrations well enough to cause the random death spins? i thought the other three tightly seated screw should provide substantial support already on their own as my maiden flight went well.

2. if only to accept the root cause of the problem, i can only assume the loose bolt could be (very slightly and mildly) rubbing against the CF frame during flight. the random nature of death spin events dictated by the resonance of the bolts against the CF frame.

3. does a less than level AIO cause any issues? again i was able to fet away with the maiden flight on this one.

pardon the truly newbie moments here. while i know that gyros can be sensitive, are they really that sensitive as i may have discovered now??

I was hoping to see the Betaflight OSD warning that would give a hint what went wrong but the quad simply seems to spin out.

Do your motors feel hot when it does this? One reason could be a ESC desync.

3 screws are sufficient to hold the FC in place and a loose screw should not cause such a spin out.

Does the quad move without any jitters in the Betaflight configurator? Another cause can be the gyro.

(31-Dec-2021, 11:15 AM)kafie1980 Wrote: I was hoping to see the Betaflight OSD warning that would give a hint what went wrong but the quad simply seems to spin out.

Do your motors feel hot when it does this? One reason could be a ESC desync.

3 screws are sufficient to hold the FC in place and a loose screw should not cause such a spin out.

Does the quad move without any jitters in the Betaflight configurator? Another cause can be the gyro.

the OSD is fine the entire time during flight on the goggle side, so i found it odd it was intermittent as recorded by the goggles’ dvr during playback. 

the motors were very cool, not even warm during any of the flight sessions, death spins included!

while i also agree the three screws should be substantial to hold things in place, i can only conclude the loose screw in front as the culprit after putting in three uneventful 15min flights after tightening it down. i am still baffled how things went ok after just tightening a measly screw! as anyone may think something more serious could have been the cause of the random death spins.

and finally the quad did not exhibit any jitters in the BF configurator. 

if only to give merit and define how the loose screw may cause the death spin i can only think of motor/prop vibration passed onto the carbon frame, the loose screw rubbing intermittently against the frame, throwing off the gyro function as the AIO board adversely reacts to the resonance. 

i shall do several test flights in the coming days to further validate if all is well as the uneventful flights have proven. i hope to do it in the nearby golf driving range where i have a clear open field making failsafe events easily retrievable. since the RXLOSS events also occured during the loose screw issue, i am hoping this will be diminished or eliminated as well.

funny but while we all want to believe there is actually a scientific explanation to all of this, my hunch over the loose screw is the best guess i could derive given the absence of any other suspect.

additonal update:

after looking closely at the crux3 AIO solder pads, i have finally identified the barrel shaped component sitting behind the camera. it is an actual buzzer which was not present in the review videos of earlier releases. how convenient this came during my numerous death spin episodes yesterday. it is acceptably loud enough to be heard above the noise floor of my flying site. without it the task of searching for such a tiny quad would be difficult even in generally low cut grass. at one point it crashed on a pile of fallen branches, i could not even see the darn thing right in front of me as it appeared well blended into the mix!