Twitchity quad with power board - test build

[jhitesma]

I have 3 20a BS ESC's I could experiment with. Think I may just order a set of the bs12 clones from RTFQ and give them a go though. Would rather have it in the air than trying to determine on the bench if the motor sounds any better. I see the bs12 clones from RTFQ actually have programming pads so they're a step up from the real deal and will be easier to reflash with blheli if I go that route. But first...

If you could check your PID's and let me know that would be great...I'm running closer to 2-3 so maybe these just really want considerably lower PID's than I expected. I've dropped down to 1.7 but was hesitant to go any lower ( I run around 7 on my knuckle with 2212 Angels and 8" props - it used to run around 2 when I used the original WII gyro and stock ESC's but once I upgraded to the MPU-6050 I was able to push them up to around 4-5 and once I flashed to simonk I was able to keep pushing them and get tighter response.) Maybe I just need to really drop my PID's lower than I expected on this setup. I may give that a quick try over lunch. I started around 2 and it was ok, but when I bumped it up to 3 it really felt great - but shortly after was when all my problems began and I haven't gone lower than 1.7 since...maybe my tune is my issue. Just so many variables to test...and I admit with the lack of built in USB I'm really lazy about changing parameters on the afromini since hooking up the FTDI is even more of a pain now that I have the top cage installed.

Horizon really does make flips easy, but it starts feeling so limiting after trying acro I still like horizon for showing off in tight places, but when I have more recovery room acro is just so much more liberating to fly now. I'm dying to see what you can do if you get out to a bigger field!

 

[jhitesma]

Wow, jhitesma, nice afternoon build.

Kinda cool watching you build on the kitchen counter with life going on all around you. I almost thought the Cheerios cereal box was gonna get grabbed and just find its way patched into the plane.

It was a fun little build. Fixed the motor up last night (it had issues out of the box with too much endplay but I now know how to reposition the bell to fix that!) but still have to make some kind of mount for it. Got it working with my stock 9x RX and radio is all set...but for some reason when I switch to a lemon 6ch (which I have a half dozen or so of so I'd rather use right now) things are all screwey....not sure what's going on...seems like more than just channel order. I've used this RX before and didn't have these issues.

Real bummer on that build was I wasted almost an hour (not shown in the video) trying to figure out the lemon rx before realizing that part of the problem was I was using a broken servo :black_eyed: swapped it for one that seemed to be working...but then once I got the TX setup and started testing again I discovered that the one I swapped actually had damaged gears and under load started popping and chattering So I've got to get that servo swapped before I even have it in the air. Grrr.

I'm just not having a much luck with anything RC related lately it seems!

 

[Twitchity]

I'll plug in my quad and get you some screen shots from Baseflight when I get home from work in a few hours. There's an empty field right down from my work I've been thinking about going to to fly, but it's right next to a small college and an apartment complex... The last thing I need is someone calling the cops on me and saying I was trying to spy on them. I'd really like to fly there so I can practice in acro mode since the grass (weeds) are fairly tall and would provide a nice soft landing area for all of my mistakes.

If I fly out there, it may get lost in the weeds without a buzzer... I need one anyways for the low voltage alarm, but I can't seem to find one I like. What is the smallest possible buzzer I could get for my Naze? They are ugly to look at so I want something so small it's indistinguishable from another component on the Naze... I know that won't be possible, but I do want the smallest buzzer I can get.

 

[cranialrectosis]

Grrr.

I'm just not having a much luck with anything RC related lately it seems!

That was me last week with the berings and popping ESCs and motors. :black_eyed:

Sometimes you just need to walk away, BBQ some ribs, play Sonic the Hedgehog with your wife and have a beer.

 

[lvzx14]

Looking good! I haven't read the whole thread yet but it looks similar to my moto warpquad. I love acro frames, if someone could incorporate a small camera and vtx that's actually shielded from crashes that would be amazing.

 

[jhitesma]

That was me last week with the berings and popping ESCs and motors. :black_eyed:

Sometimes you just need to walk away, BBQ some ribs, play Sonic the Hedgehog with your wife and have a beer.

I think a fleet of gremlins may have moved in over the western US last week

No beer for me right now with the meds I'm taking But I did bust out the good old charcoal grill for some real burgers (we almost never eat red meat since I changed my eating habits 2.5 years ago)

My wife doesn't play video games though...well she does but she's horrible at them and gets frustrated quick. And my daughter doesn't quite have the hand eye coordination to play with me yet (though she's getting better and enjoys the limited screen time we allow her with our phones/tablets and the pbskids website) I'm hoping she'll be up for some mario (I was never a huge sonic fan ) in a few more months

But the burgers over charcoal and the FT-22 build were pretty therapeutic And another month or so and the weather will be nice enough I can start homebrewing again so good beer is on the horizon as well and that's always nice to look forward to!

 

[Twitchity]

lvzx14... I hate you for putting that idea into my head about the camera... Now I'm looking at something like this http://www.myrcmart.com/walkera-58ghz-video-camera-with-transmitter-hmtx5805-p-6369.html and mount it to the cage so it can be easily removed/installed for when I want FPV on the quad...

 

[Twitchity]

Here's the settings I'm using on the Naze32

 

[jhitesma]

Well that's interesting...that's the opposite of what I was expecting. Your P's are up at 4!

I gave your settings a quick try over lunch...it flew and it was fairly stable...but it was acting odd and not tracking well, so I still think I've got a hardware issue. After I did a flip it got really hard to control like the loops were all out of whack.

I assume you haven't changed your gyro_lpf at all? (That has to be done through the CLI. You have to do 'set gyro_lpf' to see what it's currently set at.) I'm at the stock 42 right now but it was behaving better turned down to 20...but going down to 20 indicates serious vibration issues - again leading me to suspect hardware issues or my FC mounting.

On the upside my motors sounded smooth today And they don't have that high pitched whine yours did in your video. (I didn't have time to put my camera on my hat and catch any video.)

Maybe I will order some new ESC's.....

 

[Twitchity]

I just checked my gyro_lpf and its still at 42, which sounds right since I haven't changed it. The only settings I adjusted were pitch/yaw/rcrate/expo. I haven't touched any of the PID since it's flying just fine for me.

I really hope it's those ESCs giving you the issue. I was over at my parents this past weekend and my dad brought out his stethoscope used to locate car noises and tried to find the whine on my quad. His best guess was the sound is coming from the ESCs which could make sense. My motors all feel smooth and the quad flies great. Hopefully you'll get it sorted out once your parts from MRM come in. It would be interesting to throw the new ESCs on this quad real quick to see if it performs how it should before they get put on your new build. That way you'd eliminate one more possibility before purchasing new parts.

Also, are P's of 4 really high? I haven't ventured too far into tuning a Naze

 

[Twitchity]

Had to get another quick flight in before the rain. Welcome to the "Sunshine State" in Summer...

I bumped the pitch rate up form .75 to .8 for this flight, but didn't really see much of a difference (if any at all). What is the recommended increments to adjust the settings when trying to tune?

 

[jhitesma]

P of 4 sounds kind of high to me for a mini. It's higher than the usual starting point on warps at least where they start with 2.1

But ideal PID's vary depending on so much it's hard to say for sure. There's a lot of wiggle room where it will fly - but with the right PID's it just feels so much more locked and responsive.

The sound on yours sounds like PWM noise to me. I'm guessing those emax ESC's are running at a lower PWM rate and causing that noise. It's probably not actually coming from the ESC's but is caused by them. Kind of like how ESC's make motors play tones. The higher PWM rates are less audible. I could try turning the PWM rate down in blheli and probably reproduce it.

Yours is looking great! I'm really starting to think it's my ESC's at this point. I'm going to try adding more isolation to my FC first though since that's almost free

 

[Twitchity]

Is there a way to change the PWM rate on the Naze, or does it have to be done when flashing the ESCs?

 

[jhitesma]

You can change the PWM rate used to talk to the ESC. But the rate that the ESC uses to control the motors had to be done by flashing the ESC. The rate used between the FC and the ESC won't cause audible noise, it's the rate the motors are controlled at that can become audible if it's slow enough.

I'll have a set of those esc's in a few days and we'll see if I get that same whine with them...I wouldn't be surprised if I do.

Or it could be your bearings...but it sounds more like PWM noise to me. Bearings tend to growl more. Though swapping mine for fresh did get rid of the whine at slow RPM's (like turning them by hand) so...tough call.

 

[FinalGlideAus]

The noise sounds like PWM noise to me too.

Don't get caught up on the PID numbers too much. They are what they are and they will change for different frames, motors, props and so on as the PID loop is different. Heck, even using exactly the same frame and setup can differ because the harmonics going through each frame can be different. Ever since getting the KISS esc's I've devoted most of my spare time to understanding as best I can how to tune a Naze by reading, trial and error and picking the brains of the guys I know who understand PID controllers and Naze32's on a more professional level and you get to a point where you start to know how much you don't know . Those motors being not as strong as the Sunnysky's may warrant a higher P gain but it's hard to determine with out flying it.

RCrate is just like dual rates on your tx. Pitch/Roll rate acts like dual rates but also reduces the PID's as you move away from the center stick which stops the FC fighting your control input so allowing a faster response as you move away from center stick but still allows a locked in feeling near the center. Think of it as expo but linear.

 

[Tritium]

Hey Twitch, what battery are you flying?

I finally got mine outdoors briefly this evening (sorry no video). It was rock stable except for a few throttle pulses but I am flying with a Naze Acro that was pulled from a Armattan build as "bad" and I reworked it. I tried a 2200mAh 3S battery because it was the only one I had charged up. Esc's were just a bit warm and motors ambient. Wind was 10 with gust to 17mph. My pid's look just about like yours too. I do like these Cobra's 1960's with the 6X4.5 props a lot.

Thurmond

 

[Brainstorm]

Here's a closeup shot of the FC mounted. I thought I had one posted, but it looks like I don't.

That's low-profile alright, Twitchity! Thanks for posting the shot of the mounted FC. I pictured it in my mind, but the real deal has more detail.

I have the Flip Pro on my Warqpuad configured the same way as your Naze. Lemon RX on attached on top, low-profile headers on bottom with two servo plugs to organize the wires. Yours looks cleaner.

As for the idea of using only FC and PDB for structure, you are absolutely right about the 15g of top plate being worthwhile. It's just fascinating to me how lightweight things can get when you start using traditionally non-structural parts for structural purposes. It's like moving from the body-on-frame Model-T Ford (and modern trucks) to unibody construction. There's a guy on another forum who glued carbon tube arms directly to the anti-vibration plate of a brushless gimbal to make a 500g full-gimbal quad. That stuff and your work above gets my wheels turning. If only we could tinker for a living!

 

[Tritium]

Brief note on the Dollar Tree Pumpkin Strobe lights.....Last year they had 3 white leds...this year the ones I got have red..green..yellow. These are definitely going on the Twitchity quad for orientation assistance.

Thurmond

 

[jhitesma]

Agreed on PID numbers. I'm just pulling my hair out here trying to figure out if this is a tune issue or a hardware issue and if hardware which hardware

I'm going to try remounting the afromini with more foam tonight and see how it does in the morning. But at this point I'm leaning more and more towards replacing my BS12's.

And yeah, both of the pumpkin lights I got were multi color...but only 5 out of 6 led's actually work. What do you expect for $1 Can't say I'm a fan of them though. They aren't all that bright and I don't think I'd like multicolor blinking lights for orientation...just seems more confusing to me. I like steady lights But I'll probably put them on the BN Versa and see if I can't do some night flying and long camera exposures with them this winter


Oh...and a 2200?! Wow! That must have looked like a flying brick in the air! Almost as crazy as quadmovr's latest video with a 6s pack slung under a quad

 

[jhitesma]

Oh...and just to add to my frustration...the ebay seller who sold me those junk bearings is still trying to claim that they're as described and nothing is wrong with them :black_eyed: This is not my week.

I'd add in that my grandfather passed away this morning as well. But I never really knew him due to my father having issues with his family - so we only met 3-4 times. He was a WWII fighter pilot in the pacific (something I didn't know until this past year, I was under the impression he was a foot soldier in the Army and had fought in Germany since we have a german knife and PPK he claimed as war trophies and gave to my dad.) he lived a long happy life and didn't suffer long at the end. (Just a week ago he was still more than happy to tell anyone who would sit and listed about the happiest days of his life "Flying over the pacific and shooting japs out of the sky"...though his stores became a bit more embelished over the years Not sure what he flew but maybe it helps explain my love of Corsairs.

Time to catch up on my forums and then figure out a mount for the motor on that FT-22, fixed the broken servo already. Thinking maybe a little Navy blue paint in honor of my grandfather now...