450 Blade 450 spinning out of control, HELP!!!!

[Ken Jackson]

I've done it without taking it all apart but you'll only get one shoot at it. It has to be right. Good luck

 

[Lee]

Looking at an exploded view of the heli.
1) You will need to loosen the 4 bolts holding the tail boom to the frame. Slide the boom into the frame to release the tension on the belt.
2) remove the screws that hold the tail case together. Take off the side that doesn't hold all the tail assembly.
3) unhook the belt from the tail shaft pulley and turn it 180º (make sure to untwist it and not put another twist in.
4) Replace on tail shaft and reassemble.
Make sure when you slide the boom further out to re-tension the belt not to pull too hard. You should be able to push one side of the belt 2/3rds of the way across to the other side of it.

Hope this helps

 

[concept30]

Thanks guys for the help, I think i got it.

 

[concept30]

sometimes the gyro red lights starts blinking red, without me touching the radio, when the gyro is red and lock I have good tail movement but once I get in the air the tail does a 160

 

[Ken Jackson]

Wish I had a quarter for every time I've heard someone say 'Blade' and 'tail spinning out of control', HaHa. Concept dude that sucks cause sounds like you've covered everything. Have you replaced the belt drive front and rear gear set? It sounds like weird stuff (other adjective ). It has to be something not so obvious. Does it always spin the same direction when it does the 160? If so I would suspect one of the belt sprockets could be loose from its shaft but only under load. When your punching out or something. Something is slipping. It will get worse so do your best not to crash and keep trouble shooting.

Good Luck,

Ken

 

[concept30]

Thanks Ken, i heard eflight is the best, wow was they ever wrong, i think i got it worked out, for some reason i get scared if i crashed, its really cold outside so i have to wait til it warms up alot then I can do some testing.

 

[Ken Jackson]

I spun up my 450 PRO today. I just reworked the tail and started over, centered the servo, adjusted control rod length. Programmed the stop limits. I have always been uncomfortable spinning up a 450 that is having tail problems. My 500 doesn't bother me. But I always put training wheels on a 450 or smaller to test the tail and getting off the ground. Once I know the tail is locked in I take them right off.

I call it insurance, it's cheaper then replacing blades or shafts on a silly tip over. If I gotta break something it should be spectacular, LOL

Ken

 

[concept30]

i have good tail control but the gyro is not locking on my position

 

[Ken Jackson]

You need to increase the gain on your gyro. What do you have it set at now and what switch do you use to go from rate mode to heading hold mode?

Ken

- - - Updated - - -

Maybe I'm reading that wrong, if you have good tail control that's all the gyro is gonna do. Flybarless would hold the other two directions but a fly bar only has tail hold.

 

[concept30]

my gyro is set at 85 and its still not holding, I remember it hold before, when i get good head speed the tail is good but if I give alot of tail movement it starts spinning

 

[pvolcko]

I'm a bit confused. In the post three up you said you had good control of the tail (proper response to rudder inputs?), but that the tail was not holding well. In this one you say when you get good head speed the tail is good (which I take to mean it holds well), but if you give a lot of tail movement (rudder input?) it starts spinning (uncontrolled, ie it does not hold when you let up the rudder input).

1) Can you get it spun up? Note that spinning up on slick surfaces will result in some "spinning", especially if you try to spin up the head fast. During spin up putting the heli on a rougher surface will help the skids and/or tail fin grab the ground and keep it in place during spin up.

2) Can you hover it with little to no rudder input on the Tx? Does it hold properly?

3) If you give it a "pitch pump" with the collective/throttle does the tail hold position reasonably well (it may kick out a bit, up to 20 degrees, but more than that indicates a serious setup issue).

4) If you try to piroette the heli with rudder input does it go in the correct direction (right rudder result in the nose of the heli going right/clock-wise)? When yo recenter the rudder stick, does it stop and hold position?

Under which of these four scenarios will the heli start "spinning"?


If it is not #1 that is resulting in your spinning, then with that high of a gain setting it sounds like a mechanical problem.

1) Is the tail servo stripped at any point? With it powered down can you move the servo horn fully to each side with it being free and no sticking points or free spinning areas (might sound like gears are making poor contact, indicating a stripped spot)?

2) Is the tail rotor hub secure to the tail rotor shaft? The set screw is going into the flat (or dimple) on the shaft and is well centered (CW/CCW wise) on that flat?

3) If a TT system, the tail gears front and back are not loose on the shafts and the gears are making good mesh? The front gear is making good contact/mesh with the driving gear off the mainshaft?

4) If a belt system, the belt tension is tight enough? The pully has good teeth and is not slipping on the tail rotor shaft? The belt is in good condition? Good tooth rib depth along the whole belt?

The other possibility is a poor electrical connection from the Rx to the gyro to the servo. With it powered on (blades off!) wiggle the wire and connectors between these components and make sure the rudder doesn't make any odd movements and the gyro lights stay the same.

 

[concept30]

its a belt drive system, when i spool up it seems to hold, but once i give it to much left stick ( left rudder input) it starts to spin out of control, then when it starts spining to the left, i then give it a full right input and it starts spinning in that dirrection

 

[Tony]

Either your tail blades are still reversed along with the rotation, or your gyro correction direction is reversed. That is the only two things that can cause this issue.

 

[concept30]

I did what you say Tony, the belt was swisted so i fixed it, now the tail is turning clockwise. Does the MEMS gyro light suppose to blink when I give the tail a left and right movement? and stay red when not giving a rudder input?

 

[Tony]

Yes, the blinking means you are not centered on your rudder stick. Solid means it's in HH mode.

 

[pvolcko]

If you are looking at the heli from its right side, the tail rotor should rotate counter clockwise: blades sweeping up from bottom, to the front, to the top, to the rear. Tail blades should be installed appropriately for this rotation direction. If the blades are on the wrong way (trailing edge in the leading direction) it will cause the tailing edges to grab the air, overpower the servo, and tend to force the pitch to full extent, which will make it spin semi-uncontrolled.

 

[concept30]

Hope this helps, if it doesnt help, let me know and what you want me to show you in the video, and I will film it.

 

[murankar]

First thing those main blades are a bit loose. That's causing the huge wobbles on spool up. The blades should not drop when held in knife edge. Then if you give a quick jerk they should drop no more than 45°.

Second tail correction looks backwards. Try to reverse it and see what happens.


Lastly there could be binding some where in the tail control system. This means everything from the control rod to the tail hub and grips.

At this point I don't think the gain is playing a role in this issue.


Sent from my LG-E980 using Forum Runner

 

[pvolcko]

I agree, try reversing the tail correction direction in the gyro settings.

It looks like the rudder stick reverse is set correctly because that was holding the tail it in place until you let up on the stick, at which point it likely started dialing in a bunch of incorrect "correction" to fight the stick input you were giving it, and it started spinning.

To verify that your tail correction direction is correct. In heading hold mode if you place the heli down, power up the system, and then physically turn the heli CCW about 90 degrees, the tail blades should end up pointing in the direction the tail moved (in this case to the right). They will be oriented so as to push air out to the right, to correct for the uncommanded yaw. If you then move the heli back to where it started the blades should return to their starting position. Turn the heli CW 90 degrees and the tail blades will again turn into the turn (left), thus trying to push air to the left to return the tail to where it was.

With the gain as high as you have it (still at 80-90 right?) I would expect there to be a great deal of fast tail wag around the hold position once you get the correction direction set correctly. If that's the case, dial back that gain setting until it holds well on the ground and then in a hover. I'd move away from that truck or anything else before trying to hover it. Would hate to see you blade strike and end up with something dented and a heli repair job once again.

 

[concept30]

while i found my blade 450 3d setup DVD and I printed out the DX6i setup guide, and I went outside to do what yall are asking for me to do, and I flip a switch on my dx6i and that helicopter took off out of control and slam into the ground broke my tail and main blades, and my tail servo, I seen this
TGY-306G Ultra Fast/High Torque MG Digital Alloy Cased Servo 3kg / .06sec / 21g
will getting 3 for the front servos and can i also get the same servo for the tail?