Twin Hopper part 9 (endurance test with 2.4kg li-ion)

I forgot to mention in the video, but even after gluing the ailerons properly I still had to trim out the slight right yaw tendency. Looking at the props, they appear to be almost perfectly the same speed at times, so I don't think that's the issue.

[@fureter6986]

Amazing progress on twin hopper, the approach for landing at the end looks gorgeous, extremely smooth with FBWA, and looks stable in manual as well!

[@MertUluc]

We need more of that tail camera shots in the future projects! Beautiful picture and very fun pov. Great bird, thanks for sharing.

[@Etyop]

Nice job! Can't wait to see the next part

[@_Amilio_]

You've got such an awesome landscape to fly in

[@rjung_ch]

Great nerdy video, thanks Chris! Also great fix on the motor.

[@tabdougherty8549]

I just have to say, I truly look forward to these videos.

[@EnglishTurbines]

Can't quite believe you flew it with those aileron hinges not glued in place.🤔😳😮😮....Greased the landing in FBWA....without it in manual it looked rather sensitive to pitch inputs last time....That weather looked amazing, ours is crappy right now...🤔😳🙄🇬🇧

[@hirnlegorush]

love that yo still flying with that flysky cheapo tx xD well done on the twin hopper !!1

[@BensMiniToons]

Your videos have been on my mind. hope all is well!

[@AerialWaviator]

Awesome opening. It was very noticeable how much quieter the motors were operating in this video (fly byes) compared to the last (they didn't sound bad in last video, just louder). While the fix is probably temporary, at least it verified the problem and gives you flight time while you have nice late-summer, or fall weather. The glide angle seems very good, even with flaps. Nice smooth landing. With each flight, the you're really getting the Twin Hopper dialled in. Hopefully you're satisfied with, and checked-off many of the objectives you set out to explore with this Twin Hopper build.

[@taufeeqkhan2629]

what an amazing flight it was

[@goobisoft4873]

That intro was awesome 😎

[@SkyrisUK]

Beautiful Fight, That location is just glorious. you had me shouting Post. Post POST.. On That landing haha. Greased it in though, looked less of a handful than the manual landing, or maybe im just seeing it that way .. happy landings.

[@ebenwaterman5858]

Ball bearings don't have end play. Snugging the collet up solved (seemingly) the problem. Or masked it. I don't think it's over. Love your content. :)

[@iforce2d]

Yeah the bearing should still be replaced. I think all I did was press the races a bit closer for a temporary improvement.

[@ebenwaterman5858]

@@iforce2d Yup. :)

[@m3chanist]

Well... actually ball bearings do have axial play, it's a function of radial play, the contact angle and any preload. These are likely standard deep groove bearings which as they wear increase both radial and axial play (or are just high clearance to begin with). By snugging up the collar they are being used like a poor man's angular contact bearing.

[@iforce2d]

Yes, it had a tiny bit of both radial and axial play.

[@ebenwaterman5858]

@@iforce2d Well, when they wear out, you get both. They're bad, case closed. :)

[@kevinsellsit5584]

I'm new here, and I would just like to say, what a beautiful place to fly! I think I'd be saving my pennies for something I could fly in. :)

[@beesomsak6727]

Interesting comments I just started looking at this but must go back to your other videos

[@jimmcdougall9973]

102mins, wow! This is what I want to get into. I couldn’t make out all the data, but it looks like the distance traveled to be between 75 and 80km’s?

[@iforce2d]

The speed was typically a little over 60km/h, so as a rough estimate 100 minutes would be about 100km

[@pascalfust1035]

An awesome achievement in view that this is a scratch build. Congrats

[@theflyingfool]

Perhaps the big aerial & the bigger cross-section of the tail cam on the right side are the reason for the right yaw, if your lateral centre of gravity was perfect before the flight? Great video & flight!

[@iforce2d]

Nothing in particular, it's just the challenge of pushing the limits to see where they are. I'll probably make landing gear someday so I can land on that airstrip properly, then maybe try an auto mission that takes off and lands there, would be cool. But not sure if I can be bothered :)

[@tabdougherty8549]

Yesssss!

[@StefsEngineering]

Ah 12:56 is that thermal I was referring to in my previous post about the pitch oscillations during final

[@TheCANhunter]

Maybe you explain it in another video, but how do you go about designing your aircraft in regards to both CAD and design philosophy?

[@iforce2d]

Usually I have a rough idea of the type or style, and how I can make it happen with the parts I already have available, so the size and weight are limited by that. I start by using OpenVSP which is purpose-made for this, and can give a good idea of whether a design will be stable. For CAD I use whatever I happen to by trying at the time, simple designs might be QCad but for this plane I was using OnShape and Fusion 360.

[@RJMathiyazhagan]

I'm so excited to hear your opinion. Do you think using a single powerful motor is more efficient than using dual motors for the Twin Hopper flights?

[@iforce2d]

As long as a single motor is enough to launch and fly, then it will always be more efficient than two. More motors give better performance in climb, takeoff roll etc and provide redundancy for safety - the goal is not really efficiency. Look at those military drones that fly for 27 hours or whatever it is, they are all single prop.

[@RJMathiyazhagan]

@@iforce2d Hey, I really appreciate you taking the time to answer my questions. You're awesome!

[@13FPV]

If the tested capacity of the 18650 cells is done down to 2.5v, which is pretty likely, then you're gonna have way less capacity in your flying situation. My experience (I made a lot of packs with used cells) is that you have to subtract about 25% of the tested capacity to get in the ballpark of our "flying situation capacity".

[@StefsEngineering]

On your previous video I commented the following. I'd decided to repeat it because it seems you missed it. About that pitch during landing, it looks like you have some thermal activity at that construction site. lines up pretty well, My guess is that this little thermal patch gets it's air from the valley, combined causing a little tailwind but most important some thermal wind pushing up that sharp ledge you fly over during final. This hypothesis is easy to test: next time avoid flying over and close past that construction patch.

[@iforce2d]

Thermals push the entire plane up or down, they don't cause it to pitch or roll, especially at this scale. That's why glider pilots use a variometer (either audible or in my case the climb-rate display on the OSD) otherwise they would have no clue they even found a thermal. It's like swimming at the beach and getting caught in a riptide, you don't suddenly get spun around and feel it happening, you only realize when you notice you're way further from the shore than you expected. If you're flying a full size glider with a much longer wing (like 20 meters) then sometimes a very strong and tight thermal might cause one wing to bump upward, but pitch is not affected in the same way. In every flight I have done with this plane the pitch oscillations happen in manual mode with flaps down, no matter where it's flying or whether there are thermals around, and it was also happening before that hillside collapsed and exposed the sharp ledge.

[@ebenwaterman5858]

Watts/Kg (combined aircraft + payload) should be a somewhat linear function. I think, 18650 cells probably have a rather poor Watt hour/Kg spec compared to other package options. If that's what you're looking for. :)

[@skyforce1983]

So what exactly are your plans since you’ve acquired all this data? Do you plan on doing a super long distance run by autopilot? I hope so i really feel like that’s your end game and if that’s true man i can’t wait

[@iforce2d]

Nothing in particular, it's just the challenge of pushing the limits to see where they are. I'll probably make landing gear someday so I can land on that airstrip properly, then maybe try an auto mission that takes off and lands there, would be cool. But not sure if I can be bothered :)

[@lowzyyy]

As someone who know nothing about building this thing i am amazed. How much time did it take to build, calculate and learn all things about such "toy" plane? It is looking awesome and fun to have it and use it

[@iforce2d]

You might be able to get a rough idea of the build time from watching the earlier parts of the playlist: kzbin.info/aero/PLzidsatoEzehdnJEIlFkqYMygb2der2rn As for learning, I've been building 1-2 planes a year for about 6 years I guess, and watching a lot of KZbin videos of everybody else doing it too :)

[@planespeaking]

What is the long concrete's runway's purpose? And what's with the dilapidated house at the launch point?

[@wezm]

It’s for an air tractor for the farm kzbin.info/www/bejne/h6XVeolti7GgY8k

[@iforce2d]

It's for aerial top-dressing kzbin.info/www/bejne/h6XVeolti7GgY8k The building used to be a shearing shed many decades ago when sheep were run here.

[@simonl7784]

have you tested single engine performance.. I would guess it will do fine but you should know how it will fly if you loose a power plant

[@iforce2d]

That's next on my list.

[@lalbabugupta8380]

I flashed baseflight on my naze 32 bmp280 Problem is quad not using midvalue 1500 as its altitude mode as netrual position. It's using the min throttle value in case of power on the quad>> switch into baro mode>> arm the quad and lift off. And the value of throttle when you switch into altitude hold mode. Please help , i want my quad to maintain altitude at 1500 throttle value.

[@iforce2d]

The throttle required to maintain altitude depends on the weight of the aircraft and the battery voltage, and a few other things. You can't expect it to be some specific value.

[@lalbabugupta8380]

@@iforce2d in baro mode quad should not respond until mid throttle right just like in arducopter But my quad throttle response is like it is in angle or acro mode.

[@iforce2d]

I see what you mean. But I have no idea about how that systems works. If the behavior of the throttle didn't change in that mode, my first guess is maybe it didn't actually go into that mode at all. In ardupilot a mode change can be rejected if the required sensors are not working, maybe baseflight is the same. With ardupilot you would be able to figure it out from the log, or from the OSD info, or from the ground station, no idea about baseflight.

[@lalbabugupta8380]

@@iforce2dthanks sir, anyway I left baseflight and i have a beautiful project in mind. We know that those f4 flight controller are a bit expensive for first time diy people, so why not we build a current generation flight controller using 5 dollar stm32f411cue6 blackpill module running inav , because beginners have no choice rather than using those old generation multivii, cleanflight badass.

[@rjung_ch]

👍💪✌

[@spiroskatsikas]

Flying well now ,don't crash it to many hours work 😴 🙃 😪

[@technoideas5835]

Which country is this

[@wezm]

New Zealand

[@technoideas5835]

@@wezm it deserves

[@AlexCruise]

Is this the first time we've seen your face on camera? :)

[@sUASNews]

I wondered that as well!

[@AlexCruise]

Also, have you ever told the story of why there's a runway in front of your house?

[@wezm]

It’s for an air tractor on the farm kzbin.info/www/bejne/h6XVeolti7GgY8k

[@iforce2d]

It's for aerial top-dressing kzbin.info/www/bejne/h6XVeolti7GgY8k