450 First take off and landing!

[Mda1701d]

Hello all,
Well, weekend saw the first sucessfull spool ups of the newly built dominator 6s, a scary experience, even at 30% throttle!
So, after months on the sim, the first hovers etc are imminent. I would like to ask some of you more experienced guys a couple of things......
Take off, would the preference be to ease it slowly off the floor, or to pop it up quicker, to about 4ft? I have been practicing both on the sim.
During the spool ups, i found the heli would vibrate during the power down, i think this is because i was dropping the throttle on the stick, hence introducing neg pitch. Would it be better to land, then leave the stick alone and hit the throttle hold? I look forward to any advice and opinions!
Thanks alot, mark.

 

[Graham Lawrie]

Hi Mark, If you have not got training gear I would recommend using it Saves a lot of ££ if she flips Every time I do a change I put the gear on to start with. You never know what can go wrong
As for lift off I do gradual until in a wee bit then as I hover and land I do it a bit quicker when I am happy that she is stable.

The draw back with training gear is it effects how the gyro reacts and makes it awkward to compensate for. That said it stops crashing on spool up

 

[HeliDinoRC]

I am in the same boat, Mark. What I have done, at the suggestion of the people here, is set my "Normal" pitch curve to 46-48-50-75-100, which introduces only -2 and -1 degree of pitch at low throttle. I land and take off in "Normal" so when my stick is below half it does not result in a lot of negative pitch when landing and/or on the ground. Or it follows that you can just leave the stick alone and hit thottle hold as you mentioned.

I may be corrected by more experienced pilots but this is my take and two cents......

 

[murankar]

My take is I have not used training gear since 2012. Once I broke them I quit using them. Now when I do my first spool ups I do so gradually, first I get the blades spinning for a few just to see whats going on with the head, then chop the throttle since its still on the ground. On the next few spool ups I go no more than 60% just so I can see how the tail is going to act. No matter how much bench time you put in you will still have some tail issues. Most of my tail issues have been with gain and I like to solve that the best I can while on the ground. Then once I feel that the heli is doing what I think it should I get it airborne. To get mine off the ground I will get it light on the skids first, then I will give just enough pop to get it off the ground into a hover. When say pop I am not talking giant stick movement. I want the heli high enough in the air to clear the rotor wash and not above my head. Now everyone does this different and that's because all fbl units are not created equal.

 

[Barge]

Hi Mark, I'm with you, the first spool up is a bit of a shock with regards to the head speed, at 65% you really do appreciate just how dangerous these can be so safety is the main priority. I'm green as in this form of RC flying as I did my maiden flight with my 450L 6S a couple of days ago so I will not offer you any advice on what you should be doing, there are far to many highly qualified pilots here that will do that.

I have watched many videos on the 450L, and I found that they don't really prepare you for the amount of energy they release at hover throttle settings when your standing behind them for the first time, they deserve to be given the utmost respect. But after you get a couple of lift offs under your belt they are exciting and it is so easy to see the addiction for helis is out there, on top of that, the engineering is absolutely brilliant

I look forward to your reports going, enjoy.

 

[murankar]

Video is not a good way to depict power. These helis have a ton of power and if you never flown in real life nothing can prepare you for it. When I got my first 450 in the air i did it in baby steps. I was so scared to get it spooled up, even the first spool up I didnt go much beyond 25% throttle untill I got used to the blades spinning along with the noise they made. Finally after the first three packs I was ready to get in the air. At this point I was still not going that high on the throttle. I would get it in to the air then land, put it in the air and land. I did that cycle untill I felt that everything was doing what it should. I managed to get the trims worked out, got the tail solid. Finally after a quit a few packs I got into a controlled hover, mind you my hover box was huge. All of my flight from the first few months were of me hovering and for the most part I have not be able to progress much past that either. I still have fear of flying but I get enjoyment from what little flying I do do. I am in no big hurry to be a super star but I do want to at least get into sport flying.

 

[Tony]

Training gear is a MUST for any maiden, especially if you are a new(ish) pilot. One thing to remember is you are going to have the helicopter take off to the left. so once the skids leave the ground, be ready to add a LITTLE right cyclic. Don't go stick banging on this, a little will go a long way. Just remember to NOT trim out this left movement with subtrim, it's completely normal.

As for how to take off, I"m going to say it depends on if you are running a 3GX or not, and what firmware you have. If you do have a 3GX, and you are running 3.1, they yes, pop it off the ground before the spool-up has completed. Meaning once the motor is about 50% to 75% power, start adding collective and get that thing off the ground. However, if you are running 4.0, or any other gyro, then just be calm and ease it off the ground. I really hope you are NOT running 3.1 because having to pop the helicopter up and correct what it's going to do (I have no idea what it's going to do otherwise I would tell you) can be very intimidating.

And as for how to land, I do mini autos. Meaning, I will come to a hover about 2' off the ground, hit TH and start adding collective. Once your skids hit the ground, go to full negative. And in TH, I have a linear pitch curve. For what you are doing, you really need to learn how to land properly, so you will bring the helicopter down slowly, ease the skids on the ground, and once they touch, then you can either lower the throttle all the way, or again, hit TH and lower the stick all the way down.

No matter what way you do it, you WANT negative pitch (more than 2º negative) when you are on the ground. This will keep air from lifting your helicopter up when you are at 0º of pitch. this is what is called Translational Lift. It's what happens when the helicopter is in nice clean air, such as wind blowing, and creating the max amount of lift per the given pitch of the blades. If this happened, it would cause a lot of damage with just a tip over. So ALWAYS go to full negative once your skids hit the ground.

As for the vibration you were talking about, I'm almost positive that this was caused by you only giving it 30% throttle. At this throttle, you did not give it enough to swing the blades out straight so they were still not balanced. Just make sure both blades are the same tightness and you will be fine.

Hope this helps.

 

[Mda1701d]

First of all, thanks to all for answering, loads of great advice here!
I have had so many conflicting reports on using training gear with FBL, and yes, I am using the stock 3GX, ver 4. I am considering making a light weight assembly with some alloy welding rods we have here at work, bent up at the ends to stop it digging in. This would increase the footprint of the skids, but not add too much wieght or change the c of g too much. I wonder if Barge used any gear? If this was your first heli as well, what was that like to fly?
I have also suggested to phoenix that they could include some of the vibrations etc that heli go through on spool up to make it more real. I cant agree more with muranker, I have watched loads of vids of this model, it just doesn't show the power etc! I used the ipad to film the spool ups, and watching back seems a bit tame as to how I remember, but then I was lying on the floor at a safe distance trying to check the blade tracking lol!! If I can find out how to post the vid, I will, so the vibration on shut down can be seen. The blade tracking was very close, I just altered by one turn one side. Thanks for the take off advice Tony, again, the sim doesn't show this too much, I shall be very wary of the dip to the left! I have the 3GX settings all nice and soft as per your exellent vid.

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Hi Dino, your settings are similar to mine, I have a similar gentle pitch curve, and checked the blade pitch to make sure I dont have too much, and go rocketing up into space!! I am running negative as well, in case I get stuck under a gust!! Good advice also about using neg on the ground, I'll keep that in mind.

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The blade grip tightness is something I have been very carefull about Tony! I set it to hold the blades when out straight, then drop when shook. The little coaxial heli I have will shake its self over if they are not realy loose! Also, it has a habbit of dissappearing skyward with the slightest of breezes!!

 

[Barge]

Hi Mark, I have had a fair amount of flying time with my Hex, they are sort of poles apart but the controls are similar, the APM flight controller allows a huge range of tuning adjustments like the heli but it also has an auto tune feature with regards to pitch and roll. My hex is razor sharp in this area, the main reason for this tune is because in loiter mode, (altitude is maintained using a barometer, and position hold is by the GPS) the hex is solid in holding the desired location even in gusting winds, it pretty well snarls at anything the tries to move it from its set location. It is awesome to fly, but you do need fine motor skills to fly it well, and I run 15% dual rates on aileron and elevator. I also have a lot of stick time flying aircraft.

To top it off I have a lot of hours on the Phoenix sim, I always practise with everything set at full noise 3D, this has given me fairly sound orientation skills, tail in, nose in, left and right side so I believe that I will make the correct stick move to recover from an unwanted flight orientation. I must add that I will not be trying anything but tail in for quite a while with the 450L. The reason for this, and I have mentioned in a previous post, that sim flying is great for orientation practise, but compared to the real world I believe they are poles apart. Sorry to ramble on a bit but I thought a little bit of background info will help you understand where I am at prior to my maiden lift off.

I am using 3GX V3.1, I have very low vibration and I meticulously balanced the mains and tail rotor. I did not use training gear, I did spool up on a test bench to check vibration and to double check tail rotor was working in the correct direction and compensating when the heli was rotated on its axis. I then took my heli, laptop and a couple of batteries to a small local park that is always quiet. Spool up time, the butterflies were running amok in the stomach. I use Futaba gear so the settings for pitch and throttle will be based on the stick position of 0, 25, 50, 75, and 100%.

Pitch: -3, -1, +1, +5, +9.5 degrees

Throttle: 0, 30, 55, 70, 85%


The first lift off to around a metre the heli drifted to the left and the tail dropped on the ascent and there was wag in the tail. I did manage to keep it within a reasonable radius but it was very sharp on the stick movements and it was a handful, I landed the heli shiny side up and made the following adjustments.

I plugged the heli into the laptop with the 3GX software running.
I dropped the gain on the rudder by 10%.
The tail drop on ascent was adjusted by using the collective pitch elevator precompensation, I changed this value up by 10% from 50 to 60.

It lifted off a lot better with the tail staying more horizontal on ascent but I landed again and went up another 5% higher on the precompensation value which fairly well sorted that out. Airborne again and the wag had nearly gone so while it was in flight I tweaked the RD rotary dial on the Tx a bit more to correct that problem and I managed a couple of stable hovers and landed again. I must admit it is still a little bit of a handful at the moment but it is improving, that's the best part. These helis have a heap of power and are a bit nervous to start with but I'll get it tuned right I hope.

On lift off it also had the tendency to drift left which was easily compensated for with a touch of opposite aileron, but out of curiosity I rechecked the swash plate and it was out a little, a bit low on the elevator and aileron so I adjusted the pitch down to even things up, I then went back through the DIR mode to redo the setup and checked everything else out to make sure it was good to go.

I have also set a switch to activate dual rates with -30% on the aileron and elevator which should smooth out stick movements, I also dropped the rudder delay to zero from 10% as recommended by most set up videos. I may even try lowering the head speed a tad, maybe that my soften it up a bit as well.

So that was the end of my first flight with the 450L, I flew back to work the next day, I work at an iron ore mine 1500kms from home so I have to wait another six days before I fly home for the next testing session to take place, and I can't wait.

Cheers

 

[Tony]

There are conflicting reports of using training gear, but you are using 4.0 and that is a stable version on teh ground. The issue comes with the tail. But that is for a later thread. With 4, you will not have a helicopter trying to tip over when on the ground, or shouldn't if you don't have a lot of vibes. And vibrations are just intensified by training gear, which is where the conflict comes in. If it starts shaking, the training gear will keep getting worse and worse. This is about the only time I suggest a very rigid training gear, and not the thin carbon fiber.

 

[Mda1701d]

Thanks for the comprehensive write up there barge!! Nice to get some background as well. Thanks for your input tony, i made a training gear of sorts from some alloy welding rod from work, but not sure if im going to use it yet. Im a little concerned if its too springy, and does something funny to the gyro. Could all end in a big mess lol.
Tomorrow, if the wind is light, im going to try a few hops in the garden, nothing too ambitious. My wife thinks i should leave it on the shelf and save alot of hassle! It does make a nice ornament.........

 

[murankar]

My wife is the same way. Just do the quick hops and get used to the handling and adjust as needed.

Sent from my LG-E980 using Forum Runner

 

[Mda1701d]

Well chaps, its been in the air! We just put it in the back garden, and went for a few hops, longest hover was about one minute, it all seems nice and stable, thanks to tonys settings, and grahams gyros! The only strange issue was on plugging in, a constant beep from the esc, that translated as having throttle on. The stick was at zero, not chaged throtte curve etc. bit odd. I changed the throttle travel to 110% at the bottom, and it fixed it. It was very breezy, but all survived. If the wind drops later this evening, we'll walk down to the field and have a proper go! Thanks again to all who helped.