My first build and first flight & a question please

[Opto-Mystic]

Yes, my first build of a quad and my first ever flight. I was chuffed to bits that it went as well as it did. With this set up I got approximately 15 minutes flight time with the 5200ma S4 LiPo feeding DJI 2212/950Kv motors with 8inch stock plastic props

Because of limited space I had  to set myself a very limited flight box. Towards the end of the of the video, I started to push the envelope a little and was a little more vigorous with the stick - learning to get the feel of the Futaba radio sticks and the response from the F450. The height I went to a couple of times reached maybe 30~40 feet

Question, please watch the take offs. Juts before the critical moment of ';unstick';,  there seems to be a lot  ';judder/wobble'; in the arms. Is this normal or do I need to tweak the controls in Naza Assistant a little more?

Anyway, here is the video of my very first argument with Sir Isaac Newton

Critique, comments and advice will be warmly received and faithfully applied 

DJI F450 Flamewheel First Flight on Vimeo
Watch in HD on Vimeo

[Hands0n]

Looking very nice and stable it flies well.  Nicely done for a first ever flight.

While you';re learning the controls and keeping low altitudes it would be as well to get into the feel and control of the Yaw so that you can maintain orientation. 

That pre lift off judder looks a bit odd. My Naza M Lite doesn';t do that. Have you balanced your propellers. Or are they supposed to be factory balanced?  I don';t think it is a setting issue as it goes immediately you';re actually in flight. Others may have a better idea.

Sent from my Nexus 5 using Tapatalk

[Biffa]

Have you tried it without the landing gear to see if the frame by itself oscillates like that?

[Jimbodiddly]

Donald, that looks great! glad to see it in the air, i think the juddering could be that its on soft grass which is no always a even surface, try taking off on a hard surface like concrete to see if there is and reduction on the vibration.

cheers Jim

[nub]

looks really good, sounds smooth and seems stable, nice but that shudder at the the start is a bit dodgy never seen that before.

[Opto-Mystic]

* no I haven';t tried it without legs. I don';t want to de-construct it - I am ising one leg as antenna support anyway.

I will try from a concrete launch pad next time I fly it. The ';wobbling arms'; only happens when I very slowly advance the thrust and get to the point just before lift-off.

I was wondering if it was the Naza detecting some sort of imbalance and doing corrections. When I take off without spooling up so slowly, the beast gets airborne without judder.

Bearing in mind that I don';t want a ';Formula 1'; of the air rather a sedate camera carrier as it';s intended purpose is for aerial photography/videoing. Therefore I want to do slow take-offs

[XH558]

That';s a very strange judder ... but look at 2:12 - it doesn';t do it there ... but it tilts slightly one way - then when you regather it and try again the judder comes back ....how very odd   

I don';t think it';s the grass - but don';t know what else it may be because it flies smooth as you like 

[Biffa]

* no I haven';t tried it without legs. I don';t want to de-construct it - I am ising one leg as antenna support anyway.

I asked because to me it just looks like it';s hitting a particular frequency and the quad is wobbling on the legs. If it did it on the deck with out the legs on then you would know there was a definite issue.

To me it just looks like it';s a little wobbly until it';s up to speed, a lot of model helicopters do that until the blades are up and over a certain RPM. If it flies fine I would be inclined to not worry and just pop it up into the air a little quicker

[guest325]

Looks really good, especially if you';ve not been flying anything before! You';ve already grasped the principal of not moving the sticks around wildly by the looks of it, feeling around and finding what sort of input does what is perhaps the most important thing to learn.
Next thing is to have a go where you';ve got a lot more space, but make sure you don';t push the envelope in too big increments - patience is well rewarded, get yourself confident with what you';re doing before you push it any further!
So far you should be well please, hope the progress follows in the same way!

[Opto-Mystic]

Thank you all for the compliments. 

@Steve, you may be right about the wobble. EG a sympathetic resonance. I will look into that & add a dampener if needed. However:

@ Jimbo... That also may be an issue. I have noticed thar the wobble seems to only be present when on uneven ground EG: 1 leg not in contact with the ground – I will try several very slow take-offs from a flat, concrete surface later and see what is what... Other than that, i do need to do some trimming to the radio controller to make it less jittery

[Marklincs]

Thank you all for the compliments. 

@Steve, you may be right about the wobble. EG a sympathetic resonance. I will look into that & add a dampener if needed. However:

@ Jimbo... That also may be an issue. I have noticed thar the wobble seems to only be present when on uneven ground EG: 1 leg not in contact with the ground – I will try several very slow take-offs from a flat, concrete surface later and see what is what... Other than that, i do need to do some trimming to the radio controller to make it less jittery

undercarriage is flexing causing vibration fit spars between the legs to stiffen it all up.

Jittery on controls you cannot trim out -its either gains need tuning or juddering hands

what you can do is make it less sensitive around mid stick

Go into the Transmitter Menu options and Find EXPO

You want -30 Expo on aileron and Elevator both ways and you MUST go -

do not go + or you';ll make it twice as bad

[jwl940]

Opto, the white arms suggest the front of the quad, red arms the rear.  Now I guess you are standing beside the camera therefore you are flying it nose in!  Hasn';t anybody told you that';s difficult at first?     There';s a sticky about it somewhere, very well done indeed!

My first flights were done in a stonking big field with nothing to leap out and twack me, you';ve some good coordination there for flight #1 but please tell me you weren';t flying it nose in!

[Opto-Mystic]

@ Mark: When I say 'jittery' what I really mean is very small movement on the stick equals large increase in aircraft movement. Not me having DTs.

I am not sure if it is the legs are making the arms wobble or the arms making the legs react... I will experiment as and when... I have a busy week and may not be able to play much until next week.


@ jwl940:... And what wrong with flying nose in? It's like learning to drive a car – difficult at first, then easy when you know how.

He he he...No, I was not nose in – I read somewhere on the DJI website that the convention was red up front, white behind. That is how I built her. Today I had another half session after balancing props on a Du-Bro balancer that is out of balance (they are sending me a new cone). The wobble is still there.

[flybywire]

Donald, I think you have the ';DJI'; leg config?  REd front, white back?  Anyhow, it';s not the legs, I have the same on two multi';s, no vibes there.  I have an identical setup to you.  I';d say it';s possibly the props, but whatever, it';s all four at same time, by the looks.  As it';s sweet as a nut in the air, probably settle down when you get the gimbal on.
Other than that, it';s a textbook setup.  Well done! 
BTW did you make sure you got a good home lock before taking off?  Always remember, it;s the FC that';s flying that thing!  Unless of course you';re in manual mode, then it still has some inputs.

[Opto-Mystic]

Yes - a good lock - hands off hover in just a few feet.

[Opto-Mystic]

I have contacted DJI and sent them a link to the video & asked them for advice. I will post their response as & when...

[Marklincs]

Told you the undercarriage legs make spars between them make there firm.

Also have you balanced the props? ?

[Opto-Mystic]

Told you the undercarriage legs make spars between them make there firm.

Also have you balanced the props? ?

Prop balanced, yes.

At this moment in time, I do not want to add to or mod the design from that of DJI. The unit is only a week old and I don';t want DJI to absolve themselves from comment or responsibility by saying it was not put together as per manufacturers design. It is under warranty  & if I have to make a claim etc ... for a duff kit... etc - All rights reserved and all that.