Can any one help with Hummingbird setup please?

[jimw]

Hi everyone. I bought a Hummingbird v3 a couple of years ago and so far it's spent about 6 seconds in the air and gone through various replacement parts.

I read somewhere that a good idea is to put the helicopter on a hard surface and power it up and see if it slides in any particular direction, to aid in trimming it.

So I put it on the kitchen floor, scared the cat, and found that it really doesnt act as I would expect. Basically I found that if I push forward (on the non throttle stick) the blades dip forward but ALSO to the right. And if I pull back, they dip back and to the left! This means that I'm unable to control it sliding on the floor, let alone in the air, as it veers in unexpected directions.

Seemed wrong to me, so I contacted century support and was basically fobbed off :( and told that he couldnt help because he "couldnt see it" (well I could drive to california I suppose!?!). I took some pictures (attached) and that didnt help this guy either. He mostly wanted to blame it on my transmitter, but it so obviously wasnt that since the correct servos were moving... So dispondent I gave up before I smashed the thing up again.

Can any one help?

Am I wrong in my assumption; Should I be able to control it while it's sliding on the floor?

Here's the email I sent to their support - he had a real attitude on the phone, so I sucked it up in order to get some help, but it failed:

"Hi Richard, as per our phone conversation I've attached some pics of my helicopter. As I mentioned to you previously the problem is that when the helicopter is on a flat shiny surface and I throttle it up as much as possible without taking off, when I move the aileron to the right the helicopter also pitches forward and when I move the aileron to the left, it pitches backwards.

I hope the pictures demonstrate what I believe to be the problem, you can see when the flybar is perpendicular, that the paddle still moves when the aileron stick is wiggled. I am sure I dont know as much as you about helicopters, but I would imagine that when the flybar is perpendicular the paddles should be parallel to the ground even if the aileron stick is left or right.

I also notice that when looking at the blades as they spin they appear to tilt forwards when the aileron stick is right, and tilt backwards when the aileron stick is left.

I do understand that it takes practice and I certainly dont expect to be able to just throttle up and it hover without assistance - however I have experience flying gliders and know that it can be impossible to learn if it's not trimmed properly.

Is this a problem with the timing yoke?"

[eddiemoth]

Wellcome to HeliTown jimw!

I read somewhere that a good idea is to put the helicopter on a hard surface and power it up and see if it slides in any particular direction, to aid in trimming it. it is true - like you said you need to be able to control it on the floor first before you can control it in the air. And before you run it on the floor, you can disconnect your motor and check your control machanically without the blades on by turning the cyclic stick and see the swashplate moves. That would help not to scare your cat away :)

Basically I found that if I push forward (on the non throttle stick) the blades dip forward but ALSO to the right. And if I pull back, they dip back and to the left! This means that I'm unable to control it sliding on the floor, let alone in the air, as it veers in unexpected directions. How much does it turn? Unless it spins, it is normal. While you are pushing the cyclic stick up, you need to use the rudder to correct it by turning the nose to the left a little bit to correct it and the same concept is applied when you move our cyclic stick down. Unlike a multi rotor helicopter, the pilot needs to use both both sticks to keep the single rotor helicopter to hover.

Unless there is anything else that I don't know and it spins uncontrolable - it seems normal to me. Make sure that the swashplate is level when eveything is in the neutral position. The blades tracked and balanced. Regardless if it is a problem or not - you need to be fairly comfortable on the ground before get it in the air. You can do it higher each time. Not sure about your flying skills, but if you are new, training would be helpful.

Others please chime in if I am completely off track here. Keep us posted if there is any progress.

[swatson144]

The pictures look fine. So if anything is wrong it doesn't show up in the pics. You can see the same thing on mine and it flies very nicely.

Few things to look for is any binding. Don't worry about SLOP on these binding is bad. If it's been crashed sheck that the fly bar isn't broken dead center in the head, as that can cause some real weirdness. Just hold both sides of the fly bar and flex it in the middle. You shouldn't see the see saw flex. Both paddles need to be level.

After all that it would probably be on you as pilot error. They are hard to get a handle on and I have had occasion to lift off and hover others "unflyable messed up defective" helis which puts them right back to trying to hover with renewed vigor and much better results. Is it possible to go to an LHS and find someone who flies micros (avoid the accomplished glow pilots as the micros whip their butts) and let him/her try a test hover? If so it'll do you a world of good, to KNOW it flies or don't.

Steve

[The Broker]

You are right Steve, having someone look at it and try to fly it is the best idea.
Like you I also thought the pictures looked Ok, the same inputs would be needed to slide about the floor as fly in the air, all you don't have is height, the heli will still try to go all over the place.
One thing to watch out for when practising on polished floors is to maintain tight control when landing, I was showing my heli to a group of model enthusiasts and instead of landing as I normally would coming in to a hover then down, I actually came down and landed in one movement without the hover and the heli slid across the room under its own momentum. I have never seen people move so fast.
Also steve, micro's have never whipped my butt :wink: , Oh sorry you said accomplished glow pilots :D
Sue

[swatson144]

:lol: Sorry Sue, but I have seen evidence that you can hover a micro while riding farm animals! :lol:

I should clarify my statement many of the glow pilots have never touched a micro so when asked to try one the twitchness leads them to decide the "thing has issues". It's pretty common at the LHS. They have a field next door that people fly helis in. Goes kind like this.

micro heli purchased on Sat. Next saturday it is headed back to the store as defective. New owner sees a person 3d a 90 at the edge of the parking lot. Asks the pilot if he'd try his heli. New pilot gets confirmation that something is wrong, heli goes inside. Heli guy with micro experience tries it and hovers rock steady and does some FF over the race track. :shock:

Heck when I take my micros out I fully expect to run the first pack out just getting used to them again. :oops:

Not preaching to the choir but it is something to be aware of in a check out flight. I've seen a thread where a fellow was complaining about much the same type of thing. Pretty funny because when you read it closely you could pretty much tell why the heli "took off on it's own". The glow guy plugged in without 0 throttle and nothing would happen. When he hit 0 throttle the ESC began to arm but since he had moved the stick up, in a couple seconds later when the ESC armed the heli took off and "he swatted it from the air with his hand and broke it" Probably wasn't anything wrong with the heli just the glow pilot being helpful with no electric experience. Why would he worry about throttle position until he went to engage the starter? I remember switching from glow to electric with planks and all the little nuances that made it too exciting at times.


Steve

[G-MRM]

Hi Jim, so..... I take it only one servo moves with the L-R stick and the other moves with forward and aft stick?

Your photo shows the arms that hold the links from the swash to the flybar NOT at 90 deg to the flybar, well this is pinned onto the main shaft so it will be at 90 deg unless the pin is broken or bent or the head thus the flybar holder, is not locked onto the main shaft.

I only have a e-Sky FP to look at but they are almost the same, see my photo below, this shows the point I am making (I hope ! )

Let us know what you find.............. :roll:

[swatson144]

G-MRM, good point! The esky uses a double fork to hold the cyclic links vertical. The MDF and HB use a timing yoke with only 1 finger on each side to keep the upper swash rotating with the head. The offset isn't quite enough so the long links have a slight angle and the upper swash precedes the head by a few degrees. The fork on the Hbee holds the links vertical and the swash is directly under the head. Either way does fine it's just that with the century it looks a little strange but has no impact on flight, and is completely normal.

The pic below shows (I hope) what I so ineptly tried to describe. This one has the century cyclic (long links) the GWS long links are thinner and it isn't as pronounced (though makes no difference in flight).

Please excuse the AR fork repair but I hate changing frames. I also noticed that one of the short links (on mine) is off the see saw and this too can cause some control problems and might be worth looking at microman.

Steve

[G-MRM]

We sold our HB V3 but I see what your saying. ( I keep the FP just for fun flying inside) Without seeing the item or better still giving it a short test flight fault finding is so hard !
Maybe a short video of the head being moved would help ???

[swatson144]

Sure is. With no general location in his profile he could live around the block from either of us and we not know it. Maybe if he put a location in someone would volunteer to have a look?


Steve

[jimw]

Just wanted to drop a quick thank you to everyone who posted - way more than I was expecting!


I will post more later (after work) and hopefully a video of the issue.

For now just quickly can respond to some points:

eddiemoth: "How much does it turn? Unless it spins, it is normal." - it's not actually turning, more tilting, so it pulls to the right/left when it shouldnt (AFAIK)

Steve: you're right, getting someone else to try flying it would be good - I just moved to this area so have zero idea if there are any clubs etc.

G-MRM: "I take it only one servo moves with the L-R stick and the other moves with forward and aft stick" - yep.
"unless the pin is broken or bent or the head thus the flybar holder, is not locked onto the main shaft" good point, I'll have to see if I can get to this. It's quite possible it's bent.

I'm in Comox, British Columbia, Canada - so if there's anyone nearby who'd care to verify the setup for me, there's a beer or 3 in it for you!

Hope to post more later tonight.

Thanks
Jim

[swatson144]

Being that you are scooting around on the kitchen floor, I made the assumption you were using "radds school of rotary flight". If not you can find it here http://www.dream-models.com/eco/flying-index.html . Good info.

It sure sounds like everything is normal to me. Like the guy a Century I can't see how much of it is going on. I do know that for most people the first steps in learning to hover are long and difficult.

I have a friend (hah I bet that surprised a few peeps) who has 5-7 helis also. He used to swear his lift off straight up and mine don't. He was used to his. I'd get a hold of one of his and my first takeoffs looked like a huey leaving a hot LZ until I knew what to expect.

Usually a heli will wander to the left, to the point it gets up on it's right skid to remain in place. This is caused by the air blown by the tail to conteract MR torque, as it also blows the whole heli left. By that very chain of events the ground handling gets a little strange. Once you get used to it the normal response is to get off the ground when the L skid comes up. Practise makes that look like you know what you are doing.

But stick with radds and you do well.

Steve

[Sleepstalker]

Jimw well bud I am in B.C. but a darned long drive over to your neck of the woods...our stateside friends must realize of course that while we enjoy just as much real estate up here we only have 12 provinces that hold about the equivalent of 3 or 4 states each! Sigh... no wonder we drink so much beer , we get thirsty on the drive over to the neighbors BBQ!...=]

Also Swatson has GOOD tips ect and RADD's school has lots of alumni that swear by it...Sh...Sh...Sh...Sheck it Ooot!

[jimw]

Thanks for that link Steve, will definately need to read that! I know what you're saying about the drift - I've noticed it in a few videos people have posted.

Hopefully the videos below will show what's going on better - in both videos I've only been pushing forward, and you can see that the flybar is angled to the side as well as forward.

http://www.savefile.com/files/129982 (shows what happens with enough power, and just pushing forward)


http://www.savefile.com/files/130009 (hopefully shows how the flybar is tilted to the side)


Sorry for the shoddy camera work!

Thanks
Jim


PS I also uploaded one of them here http://www.filefactory.com/file/e5b58d/ incase the above doesnt work

[swatson144]

That looks so normal it was scary. I had flash backs of trying to hover myself and of my buddy, a month later in his garage.

Give Radd a read and I think he'll explain the forces at work in his drab boring manner (or somehow).

In a nut shell you have to acquire the "feel" for how much R aileron to feed in to counter the thrust of the tail rotor. It looks as if you could use a bit of r trim on the aileron though it isn't needed really nor will it hurt. Huh?that was pretty clear NOT.

I'll try to confuse the issue even more and then someone can bail me out.

The tail rotor is thrusting to the left to counter the main rotor torque. Since it aint spinning all that thrust is blowing the heli to the left. *side note 20% of all power is consumed by the tail as a rough figure. So it isn't as insubstantial as one would think* You could apply enough right trim on the aileron (roll) to counter that but the heli would be rolling to the right in free air and you'd have to hold left aileron stick to hover. Conversely you can hold right stick until it is in the air and come back toward neutral when it gets off the skids. So either trim for flight or trim for ground either way you actually have to continuously fly a heli. So it makes little difference.

More thoughts on trim. IMO use them! get what you want at that point in your learning. You are scooting on the ground trim it to act like you think is right. Worst case IMO is that it reinforces what the sticks do, and gives you a chance to think between tries. Don't think your trims will be the same from day to day. Don't think because they aren't something is wrong. Don't be surprised when you need to back off the right trim because it starts falling over on the right side vice left, as you have advanced to the point the heli "cams" over on the right skid and falls. It's nice to have someone trim it out and say "If you can't fly that it's on you" more because you know it flys then, than his trims.

Training gear? I don't like them (taste like rat which tastes like chicken). They are great when learning to fly and a tip over is costly in time and money. when a tip over involves straightening the rotor and going again I don't see the point. With an FP micro you can certainly (arguably should) use training gear to give you a early warning. The broader base tells you way before tipping that you need R or L ails. Once you get in the air for a few seconds consistently ditch them (OK I hear the huffing, remember we are talking about a very durable heli and not a 100$ crash heli). The heli flies better without acting like a pendulum. The 2 guys I'm teaching don't get to use TG and they are learning on MY coronas. :shock: Money is where my mouth is there. :lol:

Wow that was a pretty short post for me :P

Steve

[swatson144]

Here's a vid of me with my HBv2 moth. mid winter, high winds and bored stiff so I got my jones on indoors. It's 12M of tail in boredom in a 6x6 foot area. If you watch the beginning a few times you'll see the R thumb work. On lift off it is way to the right. You should also be able to see that the R thumb is in constant motion throughout, except when the heli is stable. The micros require constant supervision.

The boring vid (http://www.1upcomputer.com/storage/temps/hover5-1.wmv)

Steve

[jimw]

Thanks Steve!

Ah, yes I can fly like that, no problem ;-)

You've convinced me - the heli is fine - the problem is me :)

OK, well at least now I can read that help site, and persevere without worrying if the heli is at fault. Also I will get some training gear.

Thanks again, and I am in awe of your hover-ability.

Jim