Hexa Belt F550 Build Thread

[sutty]

Yeah, well done. Now let's cut the chit chat and see some vids, lol.

Cheers

Sutty

[jperkosk]

Here is the on-board video from yesterday's maiden. @3:03 I'm testing GPS lock mode, the guy with silly hat with Sony Bloggie on it waving with both hands at the hexa is yours truly:

[ame]http://www.youtube.com/watch?v=B2muPzwl-AM[/ame]

And this is the same flight taken from the Bloggie, full of annoying moments when I look at the live feed from GPH2:

[ame]http://www.youtube.com/watch?v=727NwbK76rY[/ame]

[Tomstoy2]

Looks pretty damn good there, Jerry! Looks like it flew pretty damn stable.

Now the gimbal headaches start.
Your landing skit in the shot means the camera is slightly tilted to the left of the mount, but due to the fact your gimbal is centered under the frame by centering the camera you may well end up seeing both skid tips. Only way around that, if it happens, is to shorten up the skids out front.

Motors in the shot can easily be gotten rid of by slightly tilting the gimbal down in neutral, but is going to come back into shot in forward flight, I'm afraid.

Roll is too fast. Makes the horizon roll quite a bit. The problem here is your servo's probably have a refresh rate of 400 whereas the Naza's puts out a refresh rate of 200.
You could reduce
the roll gain maybe down to 20-30 and compensate, leave travel at max without binding, but unless you get a real stabilizer you will never get it perfect.
That's the point that I'm at with my gimbal,
WKM introduced configurable servo refresh rates, and that helped alot. To get it better still I would need a seperate stabilizer like the Hoverfly Gimbal Stabilizer and mod my servos with outside adjustable potentiometers, but due to the direct drive system I have it won't take me all the way to the promised land.
For that I would need a belt drive system.

Still, for amature use, it's still doable and a he'll of a lot of fun.

Enjoy, my good friend, enjoy!!!

[sutty]

Congratulations Jerry. It really does look very very nice, and of course it always comes as a relief after a maiden. Enjoyed both equally, and yes it sure does look very stable. As for the gimble mount it would be a pity if you couldn't get skidless and propless videos, but from an fpv poiont of view I don't suppose that matters at all. I mean, if you look down in a real heli you would see all sorts of rubbish, including your feet, and if you looked up you would see the rotors, etc. Lol, that makes me wonder if one could overlay some things like legs and feet for extra realism. Tee hee.

Not sure I follow your logic Tom about refresh rate. As far as I can see how often the servos get told where to go at a rate less than the servo's maximum, should make no difference to where they go, or how fast they get there, unless they were really struggling for torque, in which case you would have a much more serious problem. I mean my 450 MB FBL controller can fly the whole heli perfectly well, and as fast and aggressive as hell, with very basic servos at a refresh rate of only 65Hz. I mean who the hell needs positional updates at more than the basic analogue servo refresh rate of 50Hz per second, unless there was a power issue?

Anyway, I thought Jerry said he was using cheap analogue servos for the gimble, which only have an update rate of 50Hz? Change them to digital, something with a lot more torque, and surely you are then just in the hands of the controller as to whether it works correctly or not. I know nothing about them, but I would bet they could do an awesome job just reactively, just like an fbl controller can cope with the wind, but with advance pre-comp knowledge, which should be available from the flight controller, I'm surprised you can even tell the heli is even moving at all.

Don't know really, just curious, as in my future I was hoping to see some heli based fpv solution for sure. That having been said, I was reading an article in the BMFA, which said that there are now some provisional rules for fpv flight, currently being worked on, and the proposals so far preclude both me and my 600. Me because you are not allowed to do it alone. You must have a line of sight spotter, and as a consequence you must of course remain in line of sight range too. The 600 is sort of doubly precluded because it is too heavy, without buddy boxing, and I can't really have someone buddy boxing me if I'm alone, can I, lol.

ANO Article 166 (3) says “The person in charge of a small unmanned aircraft (SUA) must maintain direct, unaided visual contact with the aircraft sufficient to monitor its flight path in relation to other aircraft, persons, vehicles, vessels and structures for the purpose of avoiding collisions.”

“When flying FPV RC of fixed wing aircraft over 1.8kg and rotorcraft over 2.5kg , the pilots MUST use a buddy box system with the pilot in charge using the master transmitter.”

Whole Article

Now you might say stuff 'em, but it's like anything else in life, if you do that, you wouldn't be insured, and whilst people get away with this all the time, including for driving cars, it's not something I'm prepared to do.

Shame.

Cheers

Sutty

[jperkosk]

Hehehe, that means that my hexa tipping the scale at 2.8kg would need a buddy box in England

No worries, Andy, the only time they're liable to check the weight of your rotorcraft is after the crash, and all the leftover pieces of FPV crashed 600 won't amount to 2.5 kg, will they? As for LOS rules you don't really need to worry, with standard Tx-Rx gear you won't be able to get much out of LOS range anyway, not in a court-provable fashion anyway.

Anyway, Andy is right, I'm using on the gimbal the metal gear version of our old cheap favourite, TowerPro SG90, I think it's called MG90, and the refresh rate in Naza is indeed set to 50Hz. I think the roll gain was set a bit too much on Saturday so I dropped it a bit, and the results have somewhat improved, but beyond that it will be difficult to improve much because of the gimbal design, which has quite a bit of both friction and slop in the roll axis.

The left skid is visible because GoPro has an off-center lens; I'll slide it back to take it out of the frame. The rotors are easy to eliminate by either pitching the camera down a bit or recording in 16:9 rather than current 4:3 screen format, so I'm not worried about that.

Anyway, I dropped the roll gain on the gimbal and flew 4 more packs, this is one of them:

[ame]http://www.youtube.com/watch?v=JAJxrvwHxDU[/ame]

Please take a note @0:45 a young club member flying around an actual beat-up Belt CP that I have helped him setup on numerous occasions . At 1:00 I'm setting GPS Lock on and walking away to the ground station, checking on the hexa a few times, then I started flying FPV, with an occasional quick LOS look, quite the opposite from the Saturday. GPH2's wide angle gives very little feel for the altitude, so you need to be able to trust the controller to maintain it.

By the end of a day I did the RTH test, the manual says to set the home position and expect RTH function to be accurate to within 10m. Results below, all I can say is wow!!!

[ame]http://www.youtube.com/watch?v=WrXFpQqWE2k[/ame]

Lastly, I have realized I have used up all and every single feature Naza-M has to offer (not all of them are tested yet, though, but they're all programmed and set-up), so just out of curiosity I started checking the specs differences between $400 Naza-M GPS and $1200 WK-M, and my first knee-jerk reaction was WTF??? So much extra money for nothing
WK-M adds:

• Octocopter control (but at the expense of gimbal stabilization, as M7 & M8 ports are shared with gimbal control)
• Tx activated RTH function. Big deal. Naza-M allegedly has a RTH as a fail-safe function only. It took me about 15 min to figure out how to program a dual-switch mix on DX18 to send fail-safe level control mode signal, effectively putting my F550 in RTH mode from Tx.
• Possibility to program and fly the waypoints (if you ready to blow additional $1k-$2.5k, depending on the number of waypoints), with some irrelevant iPad app to make it easier to program it in the field

So in conclusion: if you don't need/want waypoints (I don't), you're better off buying Naza-M GPS + DX18 combo for the same money!!!

[sutty]

Wow, I agree. That was very nice indeed. Good for you, working out that Tx activated RTH. I know another way, just turn off the Tx, lol. Does everyone know this by the way? They might be interested in how you did that over there in some forum or other?

As for way points, well you either have a need for them or not. If you did it is likely to be for business, and as such the extra money would be as nothing, and could be written off to tax anyway. Like farmers who want to count livestock, or something similar, they could criscross a large field, and examine the video later.

Cheers

Sutty

[nuttzzy]

Yea I got a bad experience with turning off the tx before the RX. I'm not gonna go that route


Beep, Beep, Honk, Honk, Over and Out Rotorhead

[jperkosk]

Originally Posted by sutty

As for way points, well you either have a need for them or not. If you did it is likely to be for business, and as such the extra money would be as nothing, and could be written off to tax anyway. Like farmers who want to count livestock, or something similar, they could criscross a large field, and examine the video later.

Can't fiscally do it with cattle, but I think my hexa has just become a fully tax-deductible item, designed for the planned future use of industrial structure inspections

[Tomstoy2]

Looking very, very good there, Jerry! She flys nice, indeed. Just wait until you get the new motors on!

Yep, the Naza does just about everything my WKM does, and I agree with your assesment of the two.
The only reason I bought my WKM instead of the Naza, well, the Naza wasn't released until about 5 months after I purchased the WKM. Hell, when I purchased mine there wasn't even a word released that they were working on it.

The big difference between the two is the firmware. Naza has had a few updates to theirs, and they got it pretty well dialed.
The WKM, however, being their professional system has undergone massive amount of firmware upgrades, fine tuning every aspect of it. I lost count after 15 upgrades.
Why so many? There is serious competition out there now. DJI had set their sites on knocking off the king, MK, and I believe they achieved that goal. Now it's a matter of keeping the rest of the pack from over taking them!

The most important firmware upgrade reciently was the ability to continue flying the Hexa in case of a motor or prop loss. Remember my pumpkin wreck? With the Naza, loss of a motor or prop in flight will drop that boom down and it will fly itself into the ground.
Now, when something gets too far out of wack the WKM will shut off the opposite motor and allow you to fly like a quad.Not something that I personally want to ever test out, ever, but others have and state it works very well indeed.

Last year saw a very serious contender, YS. A very good system, some say it is even better in some aspects. However, it's huge in sizeand weight and these multis don't have much room in the center plate foot print.

New features are soon to come out of the DJI camp for the WKM. One in particular will be very helpful, sonar for obstical avoidance.

I don't regret my purchase one little bit at all. I still remember my attempts at finding a working controller at a lower price at the time.
Remember all that trouble my FY91Q got me into? They never came out with a single firmware upgrade to make the damn thing work. Now it just sits in a pile of useless junk I have.
Never, never buy a damn thing from Feiutech!!!!

Neither the Naza nor the WKM does a good job with camera stabilization. I've never been able to get rid of the horizon tilting. I would dearly love to get it totally stable. Even so, the independant camera stabilizers are wracking their brains out trying to come out with a bullet proof system for this.

Over at Multi Rotor Forums, the largest threads there are the ones trying to deal with this issue!
Doesn't seem like it should be that hard of a thing to do, but I guess it is.
So far there is only one system that does an excellent job of it, and that is DJI's gimbal which uses stepper motors instead of servos.
At $3500 though, you would have to have very deep pockets indeed!
Can't argue with results, though. It's mind blowing.

They are soon to release a new stepper motor gimbal just for the GoPro, no idea of release date yet or cost. The new GP3 has thrown that off since the weight is 1/3rd less than the GP2 that they were setting it up for before the release of the much improved GP3!
The camera weight is a critical factor in balancing the Z gimbals! They will not tolerate any weight change beyond what the system is programmed for.
If you have nothing better to do then look up some of the vids with this DJI gimbal and watch just the arming sequence of the gimbal. When powered up, the gimbal will go thu a routine to find home and all the end points thru the full spectrum. Very impressive!

I try to help out people over at the other forum whenever I can and alway recommend the Naza to beginners. The key to the kingdom is all in the controller and the Naza does an excellent job.

However, if you are into sport flying, flips, rolls, and such the DJI is NOT for you, save your monery and get a cheap KK2 board or something. They are geared specifically for manual flying.
Dji will do ok in manual flight, but it's pretty slow. It's not going to let you do 3 flips per second.
These guys that do stunt flying are amazing!

That's not my cup of tea, though. Me, I want a stable camera ship. One I can go way out of site with and explore.

One piece of advise, Jerry, if you have not already done so, replace your prop nuts with some lock nuts. Much better than even double nuts.

Other than that, buddy, you are there! Congradulations!
Take your time learning how to fly it, gain the confidence and most of all, take that damn thing out and show use some vids of the countryside of Mexico!!!

[jperkosk]

It has calmed down yesterday, although not as much as promise in the forecast: by the time I got to the field the wind was 25-30 kph. That's right on the borderline of DJI's stated operating range for WKM of 8 m/s (Naza's operating range is not directly stated, but most specs are either identical or very similar), so there were moments when GPS lock was not holding very well and also some moments I couldn't get the hexa to move against the wind, very strange feeling, straight from my FP helis times Otherwise the stabilization worked fine, the hexa didn't feel like it wanted to flip out of control as is the case with my HPQ1 quad, altitude was maintained reasonably well given the wind, but the video came out very bumpy and near useless. Moved the left skid back and changed video format to 1280x720p @60fps (I was using 4:3 format of 1280x960p @48fps before) , so there is less vertical FOV, judge the results by yourselves:

[ame]http://www.youtube.com/watch?v=ttG9RsX03qY[/ame]

[sutty]

I'm impressed Jerry. I wouldn't say the video was useless at all. If you watch the skid tips you can see what the aircraft is doing, and so it demonstrates that the camera stabalisation is working. It looks like it would have been much worse without it, and considering the wind it looks pretty good to me.

Cheers

Sutty

[Tomstoy2]

Damn, Jerry, I think you've just about found the limit you can fly in wind! Did a damn good job of it, though, impressive!
The new motors, when you finally get them, will help out.

Might as well plan on getting some props in stock to test out when you get the new motors, different pitch and size.
As you well know, the trick is to get it to hover at mid stick when you have all up weight.
I'm sold on APC props.
You can try some electric skinny props, too. Just remember, the trick with the electric props is one size over the slo-fly props.
People that are experimenting with electric props are reporting good results with them.

This year, it looks like we will finally see some props designed specifically for multi rotors! There are a couple company's right now experimenting with designs. About time!

On your camera, you can try changing the field of view to medium to help get rid of the fish eye. That's what I'm running, works pretty well when the camera is level.

Now, for my bitch!!!
You can't believe how distressing it is for me to see leaves on the trees and green grass! You bastard.
Right now, it's -1 degrees F. here, and I got to go to bed!
Got to get a little sleep in so I can watch the Bronco's put down the Raven's, again at 2:30 PM.

Got my 7 weeks of vacation all planed and approved for the year!!!
If the Bronco's make it to the Superbowl, I plan to call in sick Feb. 3rd so I can watch it, blame it on the flu which is running at epidemic levels thru the States right now!

You're getting ready to head back out yourself pretty damn quick here now again aren't you!

[jperkosk]

Thanks guys
Yep, I'm running to the club for the last couple of flights; tomorrow 6am on the flight out to Colombia, from there Missouri again...

[jperkosk]

Turns out this wasn't a limit after all. Yesterday it was blowing 35-40 kph at the club and the trick is to just wait it out until the wind gets momentarily below 15-20 kph with the takeoff, and if it picks up later, well, you're already flying, aren't you? The video adjusted to 1920x1080p @30fps, medium FOV, so the framing is much better, fisheye greately reduced, but overall quality really is useless because of shaking. The narrower FOV is equivalent to more zoom, so it increases sensitivity to shaking as you can see below:

[ame]http://www.youtube.com/watch?v=oTJHdrJRZA4[/ame]

Off to the real airport now, no flying for 3 weeks

[Tomstoy2]

Welcome back to the frozen north, Jerry!

[sutty]

Now that was windy, and yet it did really well. You must be very pleased with it. This time I agree with you, the video was pretty much all over the place and not too pleasant to watch, but considering the wind, not bad. However the lack of skids and props and the reduced fish eye improved things a lot, so when it gets back to nice weather I expect you will get some awesome shots from it.

Cheers

Sutty

[jperkosk]

Managed to do a couple of more test flights Saturday in the morning. It wasn't calm, about 15kph wind, so the video is a bit bumpy, but not terribly so, so ran it through YT stabilization processing and this is the result:

[ame]http://www.youtube.com/watch?v=LIvP-OtNCs8[/ame]

The video is still shot using GPH2 set to 1080p, 120°FOV, 30fps. Haven't sent GPH3 up yet, as it requires some modification to the gimbal mount. By the time I recharged the batteries to try again the wind has more than doubled and everyone at the club was packing their up to leave

[jperkosk]

Realized the video became terribly smudgy after YT deshaking process, so uploaded the raw original again. It may be a bit shaky, but at least it's crispy clear. Again, this is from GPH2 set to 1080p, medium (120°) FOV, 30fps:

[ame]http://www.youtube.com/watch?v=05jI5elbtZE[/ame]

[Tomstoy2]

That's the problem with stabilization programs. From what I've seen a lot of people just cut segments, about 20 seconds worth and splice then together to distract the eye from the details.
Though, I have seen some really excellent ones. Sure they cost quite a bit for the program.

I'm really hoping that these new bl direct drive gimbals hold up to the hype as I appreciate raw footage.

So, how was the frozen north?

[sutty]

Nice Jerry, as you say, clear, but a bit shaky. I'm losing the plot on this fish eye thing, and the required settings, etc. That didn't look too bad to me, so if it is clear, and not that bad for fish eye, in that mode, then maybe it would be a good choice for me for a new hat cam? Fish eye might not be so appaernet when you are following the object at the centre of the frame, as would be the case with hat cam flights?

Cheers

Sutty