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Old May 22, 2011, 08:14 AM
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Denmark, Syddanmark, Haderslev
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Question
SymaS107 take off problem

Hi,

I'm happy with my Syma S107, I have it for a short time now.
The S107 is stable, easy to fly but not fast.
The last few times when I start taking off the heli is shaking for a while and then hoovering.
Any idea what the reason can be?

Here you can see a short film where I use full throttle to take off and fly forward :
Syma S107 take off problem.MPG (0 min 36 sec)


Regard, Rolver
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Old May 22, 2011, 09:23 AM
2011 - Year of the clones!!!
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Australia, SA, Adelaide
Joined Nov 2010
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Taking a guess here, but it's possible the main shaft that the rotors are attached to has slipped up or down a little bit thus causing the gears at the bottom not to mesh properly.
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Old May 22, 2011, 09:37 AM
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Quote:
Originally Posted by Frank_fjs View Post
Taking a guess here, but it's possible the main shaft that the rotors are attached to has slipped up or down a little bit thus causing the gears at the bottom not to mesh properly.
Hi Frank,
Thanks for the reaction. I'm completely new in this , how can I check it?
I had an idea that it was the lipo.

Reagrds, Rolver
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Old May 22, 2011, 10:14 AM
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was it shaking? or doing a slow spin. If it is the slow spin, I think frank is correct.
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Old May 22, 2011, 11:51 AM
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Main rotor (upper?) hub may be slipping on the shaft. Hold the gears in place and see if you can turn the rotor by hand.

Could be the setscrew is loose. Be careful to try to get it set back into the detent in the side of the shaft while tightening - tricky because you can't see it so work by feel.
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Old May 22, 2011, 01:44 PM
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The rotor is not slipping on the shaft, I checked both.
The Heli is shaking bit and then it is taking off

Again I have no experience, maybe I have to go to a shop.
It is a nice heli, which I like to keep.

Regards, Rolver
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Old May 22, 2011, 02:22 PM
NotAnotherMomentLostToSei zures
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After watching the vid several times (and i don't consider myself a guru of the 107) it's possible the blades are too loose in the grips. The reason I think this, is because this is the weirdest vid I have ever seen. Spinning CCW and a little shaking goes away after more throttle is applied and now the heli becomes stable. The blades are that their highest centrifugal force. Just a guess.

Mike.
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Old May 22, 2011, 03:26 PM
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Quote:
Originally Posted by Chap1012 View Post
After watching the vid several times (and i don't consider myself a guru of the 107) it's possible the blades are too loose in the grips. The reason I think this, is because this is the weirdest vid I have ever seen. Spinning CCW and a little shaking goes away after more throttle is applied and now the heli becomes stable. The blades are that their highest centrifugal force. Just a guess.

Mike.
Hi Mike,

I give it a try tomorrow, I will come back on it.
From where i started in the vid, there was inmediately full throttle.
It looks like once the heli takes off the rotors are turning faster. Once in the air it is a charme to fly, also with nearly no wind outside.

Regards, Rolver
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Old May 22, 2011, 03:40 PM
NotAnotherMomentLostToSei zures
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You did not crash it right? About how many flights do you have on it? I am just curious. Yes, I believe something is happening once the heli reaches full spin. This is why my guess was the blades. They are suppose to be loose BUT, not "too" loose. When they are too loose, they now become floppy at the root. Good luck.

Mike.
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Old May 22, 2011, 03:57 PM
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Quote:
Originally Posted by Chap1012 View Post
You did not crash it right? About how many flights do you have on it? I am just curious. Yes, I believe something is happening once the heli reaches full spin. This is why my guess was the blades. They are suppose to be loose BUT, not "too" loose. When they are too loose, they now become floppy at the root. Good luck.

Mike.
No serious crashes, once it was ended up in the grass from 1 meter high.
Total flights: about 25

Regards, Rolver
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Old May 22, 2011, 08:50 PM
2011 - Year of the clones!!!
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Just to clarify, you applied full throttle at the very beginning of the video, and when the heli was on the ground slowly spinning this was under full throttle?

So there is a delay under full throttle before it takes off?

If so, this is very interesting. Could be many things responsible for this. Loose connection in the wiring or a motor that is on its way out are two things that come to mind. Seeing how it is spinning anticlockwise, it would suggest to me that the top blades are overpowering the bottom blades. Does the motor at the front of the heli get noticeably hotter than the one at the rear?
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Old May 23, 2011, 02:31 AM
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I tightened the rotor screws a bit with no result. The motor warmth is equal fore and aft, actually it is not getting so warm.
When the Syma is hanging in the air with about half throttle it is stable not rotating at all, when I give full throttle it is rotating. You have to trim continuous.

Here a second film where you can see that 1 time it takes off perfect, the second time it is shaking, both times with full throttle from start.

Shaking Syma (0 min 25 sec)


Maybe I have to buy another one and keep this one for spare parts?

Regards, Rolver
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Old May 23, 2011, 09:51 AM
NotAnotherMomentLostToSei zures
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^^^^
Do you mean you tightened the "blade screws" on the "blade grip"??? That is the darnest thing I have ever seen. I wonder if the gyro has anything to do with this? Maybe you could take it apart and look for loose wiring or bad solder joints? I'm just throwing ideas out there now.

Mike.
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Old May 23, 2011, 10:13 AM
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I am wondering if you have a slipping pinion gear on one of the motors. That can explain why it is slow getting up and spinning at first. Either that or one of the motors is drawing slightly more amps as it starts to spin up. I have a feeling if both motors were replaced the problem would be gone.

The main gears are tight and it flies OK once it gets going, that sort of leaves the problem with one or both of the motors. Check to see if the pinion gears on the motors are tight by trying to pry them up or down ever so gently. I had one pop right off one of my helis when my grandson crashed it.
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Old May 23, 2011, 02:27 PM
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Hi, at the moment I have to pay Euro € 25.00 for a complete new Syma S107.

When I have to disassemble mine, order new spareparts (with freightcosts) and spend hours on it to get it working (or not) it will cost me more the a new one.
Then I have the old one for spare parts or to experiment with it and meanwhile I can fly the new S107.

When it was a small or direct recognised thing it was it worth to spend some time on it. I'm also not a micro hobbyist with solder etc.For me it is a very relaxing thing to fly through my house after work and not work on it.

I was happy surprised with all the advices and reactions from you all, it is good to see that people will help each other in their hobby. Thanks for your reactions. I should probebly make an operation on my Syma if I was not so busy in my work.


Thanks and regards, Rolver
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Last edited by Rolver; May 24, 2011 at 01:56 AM.
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