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Interesting Hover problem - 2/28/2007 2:03:01 PM   
alienteabagger


 

Posts: 327
Joined: 2/28/2007
From: miami, FL, USA
Status: offline 		First of all let me say hello to all you heli pilots out there!! I've been flying helis for about 3 years with a 1 year hiatus in between. Started out with a 4ch Piccolo fixed pitch, last week was at a hobby shop buying parts to fix up my 1/8 nitro buggy and a little heli called the Axe CP caught my attention. So I bought it, took it home, charged it up and went for my first hover.

Now for some odd reason the heli acts as if it was on the end of some crazy pendulum. It'll want to swing side to side in a gentle sort of way. Sometimes it'll go back and forth. It always bobs up and down. I haven't gotten the severe drop out of sky that I have read about on this forum. It will do this with or without the idle up switch on. The paddles are leveled out and the main blades are tracking correctly. I know it can't just be the way this particular heli is because I've seen a few videos of out the box helis hovering steady as a rock.

Anybody have a clue whats going on?

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RE: Interesting Hover problem - 2/28/2007 5:59:10 PM   
Prontow



Posts: 65
Joined: 1/5/2007
From: Dyersburg, TN, USA
Status: offline 		Hey Alienteabagger, the stock servos are pretty sloppy, many upgrade to the Hi-Tec HS-55 servos. The extra slop might cause some bobbing and weaving. It's a easy upgrade and really makes a difference in how the CP hovers. The bobbing up and down, well I haven't heard anyone else talk of this so I thought I was the only one. I figured that as the tail motor or servos were working they are pulling power from the main motor, so if the gyro is correcting the tail the main motor is slowing down just a bit and you loose altitude. I have found it sort of soothing in a strange sort of way. I am new to heli's and I have had my little AXE CP for about two months. I have gotten tail in hovering down pretty good and am currently working on my sim for left and right side hovering. I am having a ball with all this, a lot more challenging than RC planes that is for sure. Plus I can practice at night in my shop.

(in reply to alienteabagger)
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RE: Interesting Hover problem - 2/28/2007 11:52:38 PM   
PilotLight



Posts: 889
Joined: 8/15/2003
From: Benton Harbor, MI, USA
Status: online 		Try getting on the collective faster and practice for a bit. If the problem still exists, get some video so we can see what's happening.

It will "swing" and go up and down as you are practicing hovering if you are behind on the corrections. I call it the toilet bowl effect. It can start going in circles and gets higher around the edges of your flying area. As the heli is moving through the air and you try to correct it, when you pull the leading edge of the rotating main disc up, it will tend to climb unless you reduce collective. For example; the heli is going forward away from you, you pull back on the cyclic, the heli will pitch nose up, climb, stop forward motion then start going backwards and descending. Now you push forward cyclic and rear of heli goes up, heli climbs, tilts nose down and starts descending and moving forward all over again. Low in the middle and high at the edges. You just have to adjust faster both collective and cyclic.

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RE: Interesting Hover problem - 3/1/2007 3:47:08 AM   
alienteabagger


 

Posts: 327
Joined: 2/28/2007
From: miami, FL, USA
Status: offline 		YES!!! This is exactly what its doing!!!!!
So I guess I need to work more on 'anticipating' which way the heli is about to go so I can correct accordingly? Is there anyway to get the heli itself to respond quicker to control inputs (besides getting better servos which Im ordering now). It does seem to have a delay between when I move the stick(s) and the heli responds.

quote:

ORIGINAL: PilotLight

Try getting on the collective faster and practice for a bit. If the problem still exists, get some video so we can see what's happening.

It will "swing" and go up and down as you are practicing hovering if you are behind on the corrections. I call it the toilet bowl effect. It can start going in circles and gets higher around the edges of your flying area. As the heli is moving through the air and you try to correct it, when you pull the leading edge of the rotating main disc up, it will tend to climb unless you reduce collective. For example; the heli is going forward away from you, you pull back on the cyclic, the heli will pitch nose up, climb, stop forward motion then start going backwards and descending. Now you push forward cyclic and rear of heli goes up, heli climbs, tilts nose down and starts descending and moving forward all over again. Low in the middle and high at the edges. You just have to adjust faster both collective and cyclic.



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RE: Interesting Hover problem - 3/1/2007 4:04:07 AM   
AirforceRcks



Posts: 255
Joined: 11/19/2005
From: ABQ, NM, USA
Status: offline 		I think i have somewhat the same prob. when i look at ms servos when i move the right stick the left servo laggs.i think im gonna get a new set of hs55's.

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RE: Interesting Hover problem - 3/1/2007 8:38:38 AM   
Rotor13B


 

Posts: 253
Joined: 5/19/2003
From: Co
Status: offline 		I just ordered a oem replacement servo for mine because it's seems not to be able to find center. It didn't do this before so I'm going to test to see if the problem goes away. It's a free test so why not. If it does go away, I'm going order some hs-55's and replace all of them. Fwiw, I think this is what's causing mine to drop in altitude.

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RE: Interesting Hover problem - 3/1/2007 10:19:25 AM   
ElectricHead



Posts: 99
Joined: 11/25/2006
From: Miamisburg, OH, USA
Status: offline 		I installed hs-55's in my heli and they are much better servos. The "drops" are less but PilotLight is correct about using collective and cyclic. You have to fly both sticks. I am working my throttle/collective stick most all the time. I have got to the point where my right hand works the cyclic stick without having to think too much about it and I spend most time concentrating on working collective/tail rotor. That being said,Istill need way more fly time. Still just a newbie having good fun.


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RE: Interesting Hover problem - 3/1/2007 4:04:18 PM   
alienteabagger


 

Posts: 327
Joined: 2/28/2007
From: miami, FL, USA
Status: offline 		So yeah... I took Pilots advice and tride to anticipate where the heli was going to go and begin to correct before it began to drift off course or bob up and down..... Looks like I over did it and flew her into my pool table .... NOT having a flight sim can slightly suck :/

At any rate, luckily the only thing that broke was one of the main blades

< Message edited by alienteabagger -- 3/1/2007 4:08:47 PM >

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RE: Interesting Hover problem - 3/1/2007 6:08:33 PM   
bdavison


 

Posts: 3350
Joined: 8/23/2004
From: Warner Robins, GA, USA
Status: offline 		One other thing to consider..

If you are using a programmable radio...instead of dialing in negative expo to soften the responses....dial in positive expo to richen them up.
It will make the heli more responsive which can make it easier to fly. It sounds counterintuitive, but it does work.

I had 0 expo on my blade cp, and I re-programmed the radio to give it +20 expo, and it practically turned it into a whole new helicopter.
The blade has a nasty habit of being quite sluggish on cyclic. Making cyclic more sensitive really helped it alot.

< Message edited by bdavison -- 3/1/2007 6:10:17 PM >

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RE: Interesting Hover problem - 3/1/2007 11:00:42 PM   
ElectricHead



Posts: 99
Joined: 11/25/2006
From: Miamisburg, OH, USA
Status: offline 		My radio is stock so I use flybar weights and paddles to adjust cyclic response. This works out good for me.

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RE: Interesting Hover problem - 3/8/2007 2:04:51 PM   
alienteabagger


 

Posts: 327
Joined: 2/28/2007
From: miami, FL, USA
Status: offline 		Wel,l I finally got a couple videos up of my heli doing its little dance. Now I have installed a set of HS-55s and my main rotor blades are shorter than stock (the ones I am using are from the Blade CP).

Watching the video myself a few times it seems that anytime I correct for drift, it would drop a little. Im aware that ground effect could be causing most of the bobbing and weaving but I have flown it at about chest level and still get some bobbing and weaving. Pilotlight the 'toilet bowl' effect is all but gone (looks like the stock servos were a contributing factor on mine).

By the way I have yet to go outdoors with her and my flying area is pretty small. But I think eventually that will improve my control. Keeping the heli from hitting the pool table or a wall keeps my hands pretty busy ;]

Video #1 Video #2

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RE: Interesting Hover problem - 3/8/2007 9:15:58 PM   
Heliko



Posts: 591
Joined: 1/16/2007
From: Long Island, NY, USA
Status: offline 		Alien, I was just watching your second vid and it seems your blades are way too loose. If there not tight enough they won't track correctly causing vibration and uneven lift. If the blades aren't thick enough for the grips I would shim them with washers. Tightening up the blades and retracking them should yield a noticable difference in stability.

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RE: Interesting Hover problem - 3/9/2007 7:54:50 PM   
alienteabagger


 

Posts: 327
Joined: 2/28/2007
From: miami, FL, USA
Status: offline 		No matter how much I turn the #@$kin links I can't get the blades to track perfectly. I have even sinched the blade grips down to the point where the blades are tight and don't wiggle around and I still can't get the blades to track perfectly. The closest I have gotten them is about 1/4" apart. Will this cause some kind of problem? I only use the 'stunt switch' to check the tracking of my main blades at zero pitch.

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RE: Interesting Hover problem - 3/9/2007 9:59:20 PM   
Heliko



Posts: 591
Joined: 1/16/2007
From: Long Island, NY, USA
Status: offline 		I don't have a problem tracking my blades. Inspect the heli closely for any bent or cracked parts in the rotorhead. If you can't track the blades presently on the heli then you need to get another set. If the blades aren't tracking correctly it will cause vibration and uneven lift. This will make the heli very, very difficult to fly.

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