Twitchity quad with power board - test build

[jhitesma]

Finally got up to the park for a bit this evening. It's been a long week so I left the experimental stuff at home (the hex I'm still dialing in and the knuckle that's waiting for it's maiden with oneshot) and just took the good old beat up but reliable Twitchity quad out. Had a nice hour or so as the sun was going down and thrashed the heck out of it for a few packs:



Video is downloading from the mobius...may take awhile to edit this time though...got a lot but there's a lot of boring prop changing in there as well since I didn't bother to stop it when I crashed

Motors are making more and more noises...and the ends of the arms are getting kind of beat up. But it still flies great. Biggest problem today was the prop adapter on one motor started coming loose, drove me crazy for a set of props trying to figure out why it was flying funky

 

[narcolepticltd]

PROPS FOR THE PROP GOD!!!

Glad you finally got a chance to get out for a bit and actually run a few packs through something. looks like you had a fun session there

 

[jhitesma]

And here's the highlight reel of those crashes/flights:

 

[Balu]

Looks like I need more props than the 5 sets I got when I find time to build the Twitchity Quad in the next few weeks.

I just broke a motor on my NanoQX because it (I) lost a bearing(?)... It started to make noises and when I took the prop off, I suddenly had a microscopic brass looking part in my fingers. While trying to put it back on it decided to get lost in my carpet.

Well, that's what replacement parts are for, right?

 

[cranialrectosis]

Was that a triple flip around 4:15?

Not bad flying there, jhitesma!

 

[jhitesma]

Yeah, think I only did one triple. Was't feeling all that confident

I had wanted to do the kind of twist flip I did with my knuckle at 1:30 in this video:

But never quite felt like I had the right line to pull it off.


Balu - I'd suggest the FC props to start. They don't perform quite as well as the HQ's - but they're not as stiff so they tend not to snap in crashes quite as much. The first set of props in this video were FC's but they were already beat up and on the verge of falling apart so it didn't take much more to do them in. The rest were HQ's (5x4's and 6x3's neither of which I usually use - I was just trying to use them up.) other than one set of GemFan 6030's...but I hate those gem fans. They're weak (I broke one before I even plugged in the lipo they're so fragile!) the 5x4 HQ's outperform them and not only do they sound bad in the air they're a lot harder to see.

I usually use the FC's for fun flying since they give me plenty of performance at a great price. I save the HQ's for video and showing off - they perform better but since they're stiffer they're also more brittle and will snap instead of bend in a crash.

 

[Balu]

I got some no name 5030 props made from CF reinforced Nylon. They are supposed to be more stiff and resilient than similar ABS props (shop speak). It was the only 5"ish props the shop had in store at the time of the order... We'll see. I expect them to be done quite fast.

 

[cranialrectosis]

That was a cool flip there too jhitesma.

 

[jipp]

jhitesma - in another thread i asked about parachute chord.. and 550 was recommended but then it clicked i remember you playing with two different sizes because they wee out or something.. and in the end the wrong size turn out to be the better? im 99 percent sure you used another size that was little bigger, and in the end you decided it was much easier to thread the wires through..

A, assuming it was you, do you remember what size para-chord you went with? and if you had to buy more would you go with 550, or t he i want to say 551, but could of been some other number.. my brains cells are all mixed up so i get random thoughts cross firing which leads for a great imagination, not so much when i need a real answer. lol.
chris.

 

[jhitesma]

Nope, 550 was what I used. The other size I had was smaller - 325 - it could work for some things but is small enough to be really a pain to work with. The knuckle tau is using hot pink 550 on the ESC wires. One of these days I may get around to putting some on the hex or one of the other quads...but I move things around and crash and repair so often it just seems like too much work for a bit of vanity

 

[jhitesma]

Well, I just resurrected this quad so I may as well resurrect the thread to go with it

The DYS motors in the old 230 just finally got to me. Add in some flaky RX issues and a lack of batteries and the 230 started shedding the motors that still ran halfway decently to mini planes.

Then I got an offer to try some new 2204 motors and wanted to put them on the 230. Except the 230 still had a nanowii board and I didn't feel like dealing with an 8 bit board anymore. So the motors went on my 250 Nighthawk and and the Nighthawk's 1806's were available for the 230.

Still not in a hurry to put them on because of the RX and FC issues.

Then Balu surprised me with a Sparky2 to experiment with. The 440mhz antenna for the sparky2's built in radio would look silly on the 230, but would be nice on the 250. So that frees up the Naze32 on the 250 to swap over to the 230. 230 still has it's sat RX so should be an easy swap with everything covered.

Except the emax motor wires are enameled with a non-heat stripable enamel

And the spek sat gave me some issues: http://forum.flitetest.com/showthre...-for-the-brave&p=259151&viewfull=1#post259151

And I got my motor numbering mixed up even worse than normal: http://forum.flitetest.com/showthre...-for-the-brave&p=259682&viewfull=1#post259682

Tossed on some King Kong 6x4.5's because they're handy (and maybe the lower thrust will play nicer with the 1806's. These poor motors have been swinging HQ and FC 6x4.5's their whole life so maybe they KK's will be a nice way for them to ease into retirement.)

Then I did my first tune: http://dronin-autotown.appspot.com/...hdXRvdG93bnIYCxILVHVuZVJlc3VsdHMYgICAgKfnsAoM

Yuck. That can't be right:

Tau 4.10 ms
Predicts 19981
Spilled 0
Bias Gain Noise
Roll 0.00957004 5.65233 3044.12
Pitch 0.0147093 4.93797 2469.14
Yaw 0.0289964 7.43809 982.489

4.1ms tau isn't actually possible with the current autotune. So that's obviously a bad tune. But the noise figures are the highest I've ever seen which is another sign of a bad tune.

I didn't even bother to look at the generated PID's because there's no way it's a valid tune.

Then I remembered. I wasn't on the default PID's. I was on my tune from when this board was on the 250 with 2204's.

Reset all the PID's and ran autotune again:
http://dronin-autotown.appspot.com/...hdXRvdG93bnIYCxILVHVuZVJlc3VsdHMYgICAgJ_V8AoM

Well that's more realistic:

Tau 28.00 ms
Predicts 19982
Spilled 0
Bias Gain Noise
Roll 0.011973 10.0921 83.6512
Pitch 0.0106513 10.0137 105.77
Yaw 0.0278194 6.3632 1021.88

I was actually expecting tau of mid thirties but noise values on P/R are ok so I gave it a try.

And this little guy has never been this smooth before. Super Silky. Not as punchy as I'd like but I'm sure that's the props. I really miss flying this little guy. Maybe I do have to do one of these micro brushless builds....

 

[cranialrectosis]

Yeah, tune on a tune with dRonin or TAU doesn't always work well.

But man oh man does it work wonders from the default.