Beginner's Hubsan X4: Difficult to keep it at a certain height

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jan404

New Member
Hi, I'm really a beginner; I only flew my X4 (2MP cam version) a few times.
The flying is going ok, it's not hard to make it go forward or backward, left or right in a (pretty much :)) controlled way.
But I find it really difficult to keep it at a certain height, especially when I use the left stick to make it rotate left or right.

Is this just because I'm a beginner or are there tricks to keep the height of the copter more steady?

Also, once it's going down I have to open the throttle full to prevent it from smashing on the floor, is this normal?
 
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Hugh Hemington

Well-Known Member
No, with no components in it to detect or hold altitude, any quad will tend to rise and fall. The Hubsan X4 is known as one of the better mini-quads but they all have limitations. Smaller batteries, and those with fewer "cells" deliver less consistent power. And with lighter quads, it takes less deviation in thrust to change altitude.
It will naturally change height when you yaw because you're driving the props across the changing unstable air from another prop. Among my quads, I have an AR Parrot drone 2.0. Even with its sonic sensors in the bottom, it still can't maintain altitude indoors! My much smaller nano-quad isn't "flown" so much as wrestled continuously to keep it off walls, floor and ceiling. There is literally NO TIME to fly it in a forward direction let alone try to turn it, and altitude is it's worst direction requiring second-by-second adjustment.
Don't expect to achieve hands-free hover with the Hubsan or any other quad without active flight control components designed to make it happen.
 
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droneguy

Member
Tend to rise and fall yes. My son-in-law a competent Heli flyer can pick any of my micro Quadcopters Hubsan X4 , Ladybird V2 and with a few seconds trimming can get them all to remain at a fixed altitude indoors and out. I've seen him put the remote down for a few seconds. I struggle with Helis and cannot get hands free hover with Quads but with my thumbs on the sticks and very very slight movement I can keep my Quads in a fixed position.
 
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Ares2180

Member
It won't hover at set height, it will always either rise or fall a little. Just keep making small adjustments with throttle. Kind of like riding a dirt bike or driving a car, u let off throttle it slows down a bit give it gas it goes. Bigger quads have cruise control lol.
 
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Hugh Hemington

Well-Known Member
Larger quads also have more mass, meaning more inertia, meaning more moment-to-moment force is required to change the speed and direction of that mass. So small fluctuations in system power don't produce enough force to move a larger quad very far off course or altitude. When it takes longer to drift, the controller has longer to respond and correct.
Even when a quad is small and has an "advanced" controller, corrections need to happen faster, meaning the sensors have to be more sensitive and processor faster, when small quads tend to be cheap, with less advanced components.
I think the Hubsan is a good quad and a great value, but you can't get away from the realities of size and price giving you a beating when it comes time to fly.
 
Bill Safrit

Bill Safrit

Member
Hi Jan404. This may sound too simple. I am an all out 3D helicopter pilot. I fly both 450 and 550 class helis. You would think hovering a rotor craft would be the most simple maneuver to learn. Not so. You mentioned being a beginner. Any beginner has a tendency to over correct. I have flown the Hubsan x4 quite a bit and have no problem with hovering. Two things will help you more than anything you can do. First trim both channels on the right stick so it does not drift forward, back, or to one side or the other. Make sure you do this indoor so there is no wind factor. After this is completed simply relax while trying to hover. Being nervous while flying can be your worst enemy. One more tip for you. Do not fly outdoors if there is any kind of wind at all. The x4 is a very light machine. If you fly this quad at over 50ft a 5 mph can carry this quad away from you where you cannot fly it back to yourself. I took the one I was flying up to 100ft and was carried out over a cornfield 200 yards away out of range with the radio and no matter what I tried to do to get it back and took forever to find it. Hang in there you will get better and better with stick time.
 
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Hugh Hemington

Well-Known Member
I don't believe very small quads, at least the ones for sale today, CAN be trimmed out. With little mass it takes less variance in thrust from any prop to send it off course. Every component in a <$60 quad is specd. right on the edge and every corner is cut for weight reduction. Brushed motors (only a very few are brushless at that size) are NOT speed stable, and ones driven to be cheap small and light are less so. I don't believe a cheap 1S LIPO can provide stable power, and there is no capacitance anywhere on a micro or nano class quad that might buffer that variability, and not enough mass to smooth it out either.
At my local hobby store, the "quad guy" cannot hover anything they're willing to fly indoors. He cannot demonstrate anything holding position and altitude FINGERS off, much less for the time it takes to put the remote down and snatch it back up again. Nor will any of them remain in lateral position with only throttle adjustment.
If you learn on a very small quad with little stabilization, you are donning a hair shirt and flagellating yourself. If you enjoy that, by all means, go ahead.

Keeping a quad in the air and stable without air foils is quite a feat. It's something like flying the original F17, which would never fly without many computers making constant micro-adjustments to the control surfaces. I don't believe I've ever seen anyone plug the ESCs directly into the receiver on a quad and FLY. If folks concede that they wouldn't attempt to fly these things without a controller, I don't understand the rationale for the "machismo" of making it arbitrarily difficult.

Piloting a quad is difficult enough with just overcoming the mind trip of head-in flight, and learning 3-axis turns. I totally agree it is important to practice until maneuvering your quad becomes second nature, and flying "forward" feels natural and just laterally pitching the thing feels odd. I'm all behind that. What I don't get is the zeal for the artificial "rigor" of turning things off. We don't do it learning to drive a car!

If you buy a small quad to learn on, never make the mistake of assuming a larger one will just be larger with the same bad flight characteristics. It won't be, so don't get discouraged!
 
Bill Safrit

Bill Safrit

Member
I'm not trying to be mean Hugh. I have flown the quad in question here. I had no problem hovering at one altitude with very little input from the stix. Quads are not hard nor difficult to fly. A 6 year old can fly one with a great deal of confidence after only two days of flying one. Jan404 is not asking for advice on stabilization hardware, brushed compared to brushless, 1s lipo for stable power, or hands off hovering. Just controlling a simple small quad.
 
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Hugh Hemington

Well-Known Member
I haven't flown a Hubsan. Every small quad I have flown has been fairly miserable. Maybe they've all been bad examples or defective in some way. I flew six different micros or nanos in the store and I couldn't hover any of them and neither could the guy selling them. He got close, but his fingers were just a blur, and he crashed them all on the floor -- didn't land one back on the counter.

JAN404's initial comments were about altitude drop when yawing. Since yaw rate is limited by the percentage of all-up-weight two props can lift, most small quads are tuned to limit yaw to maintain altitude. The smaller the quad, the more demands are placed on each component, while the price point is driving down what can be spent on the parts. For what a Hubsan costs, it's a miracle.
 
Bill Safrit

Bill Safrit

Member
The Hubsan was really easy for me to hover as I mentioned before. What I did not mention is the fact that I am a 3d heli pilot with a Thunder Tiger 450 and my Trex 550. I also fly giant scale 3d aerobatic giant scale airplanes. I find quads not only simple to fly but somewhat boring. I've watched $1000+ machines in gps hold and altitude hold. I have yet to see any of them to stay in one place. They all drift. My Trex 550 hovers better than that. I'm sorry, Jan404 mentioned nothing about yaw or by another term rudder input. Jan404 I hope you took my advice and kept flying the Hubsan to get more stick time so you can fly without over correcting. Your last comment about giving the quad more throttle once going down. Does this occur toward the end of the the flight? If so you are flying while the lipo is reaching the point where the batt is at a voltage lower than the quad can operate at. If the lights are blinking this means you have reached LVC mode. (Low Voltage Cutoff) It is best not to fly the quad until it reaches LVC. When a lipo is flown down to below this point the lifespan of the lipo will be shortened dramatically. Another lipo fact for you. When not flying the lipo for say a week or so leave the lipo at about half charge. Never store a lipo almost drained. Nothing could be worse for it.
 
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Hugh Hemington

Well-Known Member
"But I find it really difficult to keep it at a certain height, especially when I use the left stick to make it rotate left or right."
That says to me that altitude changes with yaw. But no matter. I hope he's finding success with the Hubsan.
 
heath

heath

Active Member
I've been flying my Hubsan for about a month now and finally can confidently rotate it (pirouette) without much change in altitude. I think it helps to "pinch" the sticks between your thumb and forefinger instead of just using your thumbs at the top of the sticks.
 
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Spikey1973

New Member
Hey guys, newbee hubsan x4 flyer here too. Just have it two days now and i must agree that is is difficult hover.. but in the few minutes i have Flow i did seem to find some improvement. Oke. That was with a fully charged battery, and also the lighter (original) one of the two I got.. which must have help.. also new props.. and made sure the motors were pushed down completely. After a small crash I find that the dream away legs have broken away. But also that the motor has come up a little. Lighter does help the stability. Also the easy to o er (over over and another over) correct might have already decreased a little.

Anyway.. I'll do some more flying this evening and weekend and am looking forward to it
 
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