DscottM83

Im not sure if this is normal or not, and ive seen at least one other member with the same thing so can someone varify if this is normal or not.
hold your heli down and power it up. Now if I idle it up and push say forward cyclic, the blade leans forward and a little to the left. Just the opposite when pulled back. Also, when I get it into a hover and it starts to drift, when I correct for it, it bounces to the ground and then comes right back up when I remove pressure from the stick.


OH BTW, sweet we got our own forum

Heli Bat

I know for sure that my response is going to be way off, but I might as well atempt some type of guess. I can only guessthat you might be in the idle up position switch on your transmitter. When that happens, the dynamics of your blade changes from (-)negative pitch all the way to (+) positve pitch. When you are in Idle up position, this is what allows you to do stunts, 3-D or flying inverted. Make sure that you are not in that postion on the transmitter. If you are in the idle up postion, grabbing your left stick all the way down will make your Heli DIVE into the ground. It is only a guess. Sorry if this is not the answer.

Heli Bat

tgwolfwood1981

oh yeah, he is right. that is how i had a particularly nasty wreck on new's year eve. don't go to idle up until your ready for inverted flight. oh and i noticed the same with how the cyclic moved. i believe it has to do with holding the heli down. it doesn't allow the flybar to correct itself. in flight when you change the position of the cyclic the flybar changes it's angle of attack and then the body of the heli follows. sort of a self stabilization method, but when you hold the heli planted on the ground you lose that action of the body moving with the flybar. this make the cyclic seem to move diagonally. (it is trying to go in the direction of the blades, or leading edge). hope this helps.

DscottM83

def not idle up...
This has nothing to do with the throttle stick, rather the other, if you move it up and down the bade pitch also moves up and down...cool right? Well thats not the problem, its seems to have an angle to it also , meaning if i move the stick to make the heli move backword it also appears to have an angle to the left also, and it i move the stick foward to move the heli forward, the blade leans foward and alittle to the right. Im not sure if its doing this from the wind of holding it down or what.

DscottM83

tgwolfwood1981: i didnt read all of your post untill now, seems about right then.

Heli Bat

I am trying to get a visual and I think that I do have one now. I would say that if you are experiencing what the visual that I have then it is quite strange. Lets talk about what your swash plate it doing. I would think in a normal manner, if you pull your (right hand transmitter stick) or your cyclic stick all the way down, then your swash plate will tilt down towards the rear or aft of the machine. If you push your cyclic stick upward, then your swash plate should tilt downwards toward the nose or fore ship.
And likewise moving the cyclic stick to the right makes the swash plate tilt to the right hand of the machine and moving the stick to the left makes the swash plate tilt downward to the left of the machine.
I wanted to use the term swash plate becuase this is what your cyclic is controling at least this is what i am led to belive. If you are getting these pure results, then start looking at the linkages controling the blades.
Does this make sense and also forgive me if again, I don't follow you - just trying to help. Your swash plate is the first "disk" that your servos are mounted to. This really needs to be established if the Servos and Servo circuit is doing what it is supposed to do. Again, the servos I do believe are connected first to the Swash Plate, then the Swash Plate transfers that energy onto the upper blade linkage mechanism. As you move your transmitter cyclic stick look at your swash plate and make sure it has 90 degree perfect movements. Like, when you pull your cyclic all the way down, you should not see the Swash Plate pull down at like a downward 45 degree angle, that swash plate should tilt exactly 90 degrees downward. Do NOT add any left throttle at this time, just use the cyclic stick. In air plane terms, the corresponding stick movement on the righ stick would be alieron and elevator. When you are in forward flight in a way, you are controling the Heli like using the elevator ( like to do a loop - pulling back on the stick) and also using it like an alieron (like to do a roll - left and right movement).
If you have flown an airplne you know that when you are making a left or right turn (banking) the airplace, you are taught to gently pull back or add elevator to the airplane so it will not loose altitude and dive into the ground. Well the same applies for Helis too. Except with Helis, you have to control the heading or rudder of the Heli with the left stick. I know this is more info than what you wanted, I have a tendency to get wordy, but I figure that maybe some of this might be useful

Heli Bat

outtamyway

Unplug the main rotor motor and observe the two rear servos while you put the cyclic through it's paces. Do both servo arms travel the same distance? Any binding of the swashplate on the main shaft at full travel? I'm going to guess that what you are experiencing is the sum of tolerances in your linkages and servos. I say this because the direction of error definitely coincides with the direction of rotor rotation. drag on the rotor blades will push everything in those directions.
If you have access to a dual trace oscilloscope, check both rear servo outputs between the mixer and servos while you manipulate your cyclic. The pulse widths should be almost identical.

DscottM83

I did unplug the main and rear rotor, put the power stick up and down, both travel exactly the same distance/speed.

outtamyway

Oh,oh,oh,oh, I didn't read your posts clearly enough. Are you experiencing gyroscopic procession?

edit: No you couldn't be becasue you said you were holding the helicopter down in your first post. Don't listen to me... I'm a veg.

DscottM83

haha anyway i flew it today for the 1st time and it flew great

leftseat140

Your original post is word for word the same as I am having. I checked with out the motor turning, and the swash plate moves directly in the direction that I am commanding. But, when the blades are spinning, it seems to be about 10-15 degrees out of phase to the left. I would think that with rotor rotation to the right, it would cause a right shift in phase. I could live with this except for the hopping up and down every time I make a change.

I went to the store today and they said that when a correction is being made, it loses some rotor head speed and causes the heli to drop and that you have to add in some power. I can understand that, but it seems like a really large amount of down force when you try to fly it. I flew the sim at the store and had to put no where near as much correction. The store said that there is no correction for phase that they knew of as in larger helis.

So the question that I pose is this, take your Axe CP out and hover at 6" and as you make a correction for drifting, make no correction for collective. Does it slam into the ground or just settle down to the ground? Mine slams down. If I try to correct with collective with enough force to keep it off the ground, then it jumps 5 feet in the air. And yes, I don't have idle up on.

Going to the feild with some heli guys from the store on Sunday and I will let everyone know if I have a problem or if it just really takes that much correction. Thanks.

Jellyson

This is not a problem!
I have answered this very same question several times, even once today:
http://www.rcuniverse.com/forum/fb.asp?m=5216954

The helicopter rotor disc will not appear to move correctly if the helicopter is restrained in any way. As long as the _swashplate_ is moving correctly, you will be OK if the head is even approximately set up right.

Yes, what you are seeing can be attributed to gyroscopic precession, mostly.

The power loss on cyclic input can be the swashplate binding the shaft, the cyclic pitch links in the head, or even one or more bad servos.

DscottM83

Thats because i copied and pasted it
And no mine dosnt slam down but it does loose alittle altitude

Jellyson

That slamming down on cyclic input is almost certainly caused by a bad servo. They can cause a radio glitch that cuts power momentarily, and also one bad one can make all of them twitch.
See if the loss of lift is consistent with a particular direction of cyclic movement. If it is, then swap servo positions in the heli and see if the problem moves with the servo position. If it does, then you know the source and you can replace all three servos. If one is bad, the others will be soon.
Or if you have a known good servo of the same type, you can replace it one at a time for the ones in the heli, and this way identify the bad one, or eliminate servos as a cause.

kevinmahoney

I've been looking at the Axe CP from Tower Hobbies for the past month and think I've finally decided to get it. But since it's out of stock for the next few weeks, I'm doing some searching for what people think about it and stumbled across the Walkera Dragonfly #36. Reading the forums for it, they seem to have quite a bit of trouble with them. But after reading your forums, it seems people are having troubles with the Axe CP also.

The Dragonfly I can get $50 cheaper and it has a 6 channel remote with it AND I can get it right now.

I was just wondering if any of you had any experience with both of them or have opinions about them.

TinmanA51

Hi,

I have a walkera 36 with the alum parts. and i have had great sucess. with the lipo/brushless setup it flies nice.

i also have the Axe cp it flies good but i do not feel as confortable with it. The cp is not the same as Walkera. Walkera has a belt driven tail. I have found that the belt driven tail is much better. because the tail seems to be made better , more fluid and just feels
better to me.

if you add a futaba 401 gyro the Walkera is cheaper version of the mx400.

well good luck both are nice for the money.

tgwolfwood1981

i too looked at the walkera #36, but two factors made me go with the axe instead.

1) my LHS doesn't stock wakera parts (i know some trex/mx400 parts fit but seeing how this is my first heli i didn't want to deal with using other heli parts for it. they do however carry a full line of axe parts

2) I had read to many post about the electronics in the walkera. Don't get me wrong it really is a strong heli, but again i didn't want to deal with this kind of trouble with my first heli.

DscottM83

No matter what you buy your going to read about problems with it. No product is 100% failsafe, and where do people talk about their problems, forums :]