Blackout Mini Frames

[trigger]

Instead of creating a new thread, I'll expose a problem I encountered here, hoping that someone will read it

So, I've been flying my Mini-H for a week and a half now.
As a first FPV setup, and as a fairly inexperience pilot in general, I've been flying in level mode... I know, I know.

I had try to fly in rate mode before, but it was windy (20-25 kph gusts), and I had shamelessly blame my failure on the weather
Yesterday evening however, the air was perfectly still, and as I felt more confident in my abilities, I gave it another try.

The problem is, the quad had a bad tendency to pitch backward... I'm not sure what's causing it, so I'm asking you guys for ideas.

My first question is : how critical is weight balancing ?
I was using a 1800mAh battery, and while the quad was more or less balanced (the CG is somewhere around the middle of its length), being top heavy, the balance is quite unstable (if I hold it a couple millimeter more to the front or back, it quickly flips).
I then tried with a lighter 1500mAh lipo, and while it felt better, it still wanted to pitch back on occasions.

Then : can someone share their PID settings for a Mini-H running a Naze32, SS X2204 with GF 5030 (and a Mobius) ? I'm still using stock settings, and while there's no bad oscillation, I'm sure it can be fine-tuned better (I just don't know where to start).


I need to review the video from yesterday, I'll try to upload the bits where the problem happens.
But if any of you had some pointers, or have some ideas I could try to replicate (and hopefully fix) the problem, I'd be very grateful
Thanks !

 

[mmeyer]

I had this problem a while ago with a past quad and after some questioning and inspecting I put it down to vibration issues. How is the flight controller mounted and are your props balanced?

 

[trigger]

The FC is mounted on nylon standoffs, sandwiched between O-rings.

I didn't balance the props, but all the ones I tried to put on my prop balancer were perfectly balanced out of the box.
I don't have it with me (I'm on holidays) so I can't check them right now, but when I hold the Mini-H and carefully apply some throttle, I don't feel any vibration. Doesn't mean there isn't some, but at least it's not excessively bad
I'll have a look at them when I get home, thanks for the input.

 

[mmeyer]

Yeah well thats not going to be it then. Mine had significant and noticable vibration issues so i'm assuming that's not your problem

 

[FinalGlideAus]

Balancing the quad will make it fly better and more efficient but unless it's way out it won't make the tail drop. It is your PID's. You can go much higher than the stock settings. I will post mine when I get back home tomorrow or find a link to another soon.

In the meantime spend some time trying to properly balance the quad by balancing it on a straight edge from underneith. It will help also.

 

[FinalGlideAus]

Oh and I don't bother balancing my props. You go through them or nick them up too quickly

The Naze 32 handles vibrations really well.

 

[trigger]

Thanks for your input FGA.

I'll try to balance the quad front/back better. Moving the vTx to the front should help, I think.
I'd also appreciate a lot if you could share your PIDs

Here's the video.

Sorry for the dark picture, the sun was setting (too much heat during the day ^^).

I think I should point out that I'm not applying back elevator during flight (at least not intentionally...). I'm trying to learn how to keep momentum during turns, so every time the quad slows down or come to a halt, it's due to my problem of unwanted pitch.
If one of you could have a look and confirm if it's a PID issue, or just human error (which is very much a possibility :-D )...

 

[FinalGlideAus]

Your issue looks like too low I gains and a bit of P as well. Try these PID's from Boris B. I am currently interstate so this will get you going
http://forum.flitetest.com/showthre...-Pro-Help-my-brain-hurts/page2&highlight=Naze
Make sure you also set your looptime to 2500 or you may get oscillations.

My settings have changed a fair bit from these settings but I like a more twitchy setup and I have much higher thrust props now too which changes things. This setup will probably feel nice for a new H quad pilot like yourself though. Combine this and balancing your quad and you'll probably find it much better to fly.

 

[trigger]

I just come back from a quick flying session.
And...

Wow, I can't believe how much a difference those PID settings make.
Issue resolved, didn't notice any bad tendency from the quad.
I could easily fly the Mini-H around, even with my limited abilities

I could only go through a battery and a half before it got too dark (all I could see was black and noise), but I'm really relieved it wasn't something more "serious".

Thanks you so much, FGA !


Once I get back home, I'll start working on a better weight balance, find some liquid tape to protect PCBs and solder joints (the lack of landing gear makes the quad awesome at collecting grass), and maybe add an OSD (for easier battery monitoring, and because I love useless gadgets).

 

[FinalGlideAus]

Good to hear!

Now, have you set up the board camera settings properly for low light flying? That wil allow you to fly past dark in some cases.

 

[trigger]

Haven't fiddle much with the camera settings.
I should point out that I bought a camera with the IR filter, so it's not ideal for low-light flying. Still, I may be able to get some improvements.

I'll order an IR sensitive one in the near future, for comparison, and because I don't think you can have too many of those great, cheap cameras

 

[FinalGlideAus]

Even so, make sure you turn on the Wide Dynamic Range. It will make a HUGE difference to the low light capabilities. You should still be able to fly way after it's too dark to fly LOS. Some guys still fly at night under street lights with your camera with WDR turned on. I flew for a few days with it turned off and when I changed it the difference was amazing even when flying in daylight. It really helps flying in the shady patches. Try it out and report back.

 

[trigger]

Remember how I said I need to put some liquid tape on my solder joints ?
And how it was too hot during the day ?

Well, I tried to fly just now.
As I bent over the quad to plug the battery in, a drop of sweat fell on a solder joint.
Smoke ensued.


It looks like it only fried one ESC, so I guess I'm lucky.
I go back home tomorrow, I'll know what is burnt and what is okay once I get there (no soldering iron or multimeter here). I'll also keep an eye on the lipo, these things don't usually like shorts...


Anyway, I think I turned WDR on. I think it's the only thing I changed from default settings. I'll check it out tomorrow with the rest of the quad ^^

 

[joshuajcrouch]

Does anyone have any experience connecting the Naze32 to a Spektrum RX? I bought the breakout cable, but not sure how to connect it...

Pic of my WIP:

 

[Mustang7302]

It honestly doesn't matter what order you connect the wires in the breakout cable to the to the RX because you can remap the channel order on the Naz32 via the CLI. However, if you want to keep them in order, look carefully at the wires coming off the ten pin header and you'll notice the first three wires go to the same servo plug. The three wire servo plug will go into Aileron on the RX, the next wire over off the ten pin will go to Elevator and only has one wire to plug into the signal row on the RX, the last wire on the top goes to throttle, the first wire on the bottom row goes to rudder, the second wire on the bottom row goes to aux 1 (gear), and the third wire on the bottom row goes to aux 2 (flap). The last two wires for aux 3 and aux 4 are not needed, but if your RX is has eight channels, then connect them if you would like.

 

[Craftydan]

Joshua,

It's best to run through the pinouts yourself, but to get you started . . .

from the user manual, Figure 4 on the middle of page 5, you see the pinout of the edge connector, with the dot pin being the second pin on the left, followed by 1,2, and 3. (got yourself oriented?).

The first pin on the left top goes to *ANY* of the middle pins on the RX -- they're all power pins. the Dot pin goes to any of the ground pins on the RX -- you'll have to find out which side is ground and which is signal -- check for markings.

Now that we have power out of the way (and not reversed), all the remaining pins go to their matching channels . . . but notice the order is different between the Naze and Spektrum RX's, and can change if you turn the GPS settings on.

- With GPS off, it's AIL =>1, ELE => 2, THR =>3, RUD=>4, aux 1-4=>5-8.
- With GPS on, you skip 3&4 (GPS signals go in here) and THR =>5, RUD=>6, aux 1-2=>7-8.

 

[joshuajcrouch]

It honestly doesn't matter what order you connect the wires in the breakout cable to the to the RX because you can remap the channel order on the Naz32 via the CLI. However, if you want to keep them in order, look carefully at the wires coming off the ten pin header and you'll notice the first three wires go to the same servo plug. The three wire servo plug will go into Aileron on the RX, the next wire over off the ten pin will go to Elevator and only has one wire to plug into the signal row on the RX, the last wire on the top goes to throttle, the first wire on the bottom row goes to rudder, the second wire on the bottom row goes to aux 1 (gear), and the third wire on the bottom row goes to aux 2 (flap). The last two wires for aux 3 and aux 4 are not needed, but if your RX is has eight channels, then connect them if you would like.

Wonderful. Thank you so much for the detailed response. You post + Craftydan's post + the abusemark user manual was just what I needed to triangulate the solution.

I hate to say it, but you guys are much more helpful than the blackout fanboi's on rcgroups.com

 

[Craftydan]

Dude! Why all the hate? Go ahead and feel good about saying it

Glad we could help!

 

[FlyingMonkey]

Flite Test care bears strike again...

 

[FinalGlideAus]

Do I detect some rivalry....