cp vibrations
09-10-2006 | 08:11 PM
#1
Thread Starter
Senior Member
Joined: Apr 2005
Posts: 562
Likes: 0
Received 0 Likes
on
0 Posts
From: milwaukee,
WI
cp vibrations
i know this is a common post. i ballanced the blades and it still vibrates. will a small, hard to see bend cause the whole heli to vibrate?
09-10-2006 | 08:36 PM
#2
Senior Member
Joined: Aug 2006
Posts: 307
Likes: 0
Received 0 Likes
on
0 Posts
From: , CO
RE: cp vibrations
I have personally replaced the main shaft, and center hub in thoughts that something may be bent. I have balanced and verifed the flybar is straight. And I have verified my blades are in perfect condition and balanced. Here is what I have found from my BCPPro:
1) on my heli there will always be a slight vibration at slow head speeds that corrects itself when the engine is getting more and more throttle
2) this slight vibration has no effect on flight performance
3) even if you blades are balanced nicks in the blades can cause a vibration as well as a loss of tracking
4) One time I had a vibration thought the whole body of the aircraft while hovering. This was due to a couple connections on the frame being pushed out and loose. Once I made sure everything was connected well it worked fine.
Hope that helps
1) on my heli there will always be a slight vibration at slow head speeds that corrects itself when the engine is getting more and more throttle
2) this slight vibration has no effect on flight performance
3) even if you blades are balanced nicks in the blades can cause a vibration as well as a loss of tracking
4) One time I had a vibration thought the whole body of the aircraft while hovering. This was due to a couple connections on the frame being pushed out and loose. Once I made sure everything was connected well it worked fine.
Hope that helps
09-10-2006 | 08:45 PM
#3
Joined: May 2006
Posts: 5,238
Likes: 0
Received 0 Likes
on
0 Posts
From: Greenwood,
IN
RE: cp vibrations
Check the pitch and tracking. I had a pitch problem awhile back and the heli went crazy.
Even after a hard landing, believe it or not the pitch can/will change. Go figure, welcome to the heli world.
Dave / Choppersrule
Even after a hard landing, believe it or not the pitch can/will change. Go figure, welcome to the heli world.
Dave / Choppersrule
09-10-2006 | 09:04 PM
#4
Thread Starter
Senior Member
Joined: Apr 2005
Posts: 562
Likes: 0
Received 0 Likes
on
0 Posts
From: milwaukee,
WI
RE: cp vibrations
what should i all check for?
what i dont understand is that my new blade set are perfectly ballanced. and"im using a revolution ballancer" and it still vibrates. what i noticed is that the center of the head, where the screw is, dosnt spin straight. it wobbles a bit.
also, could it be that i didnt track my blades??? help[:@]
what i dont understand is that my new blade set are perfectly ballanced. and"im using a revolution ballancer" and it still vibrates. what i noticed is that the center of the head, where the screw is, dosnt spin straight. it wobbles a bit.
also, could it be that i didnt track my blades??? help[:@]
09-10-2006 | 10:00 PM
#5
Senior Member
Joined: Mar 2006
Posts: 1,195
Likes: 0
Received 0 Likes
on
0 Posts
From: mansfield,
TX
RE: cp vibrations
It has been my experience that all of the center hubs on the stock head are slightly warped. I've gone through about 6 or 7 of them now, and every single one has been very slightly warped. It does cause a slight vibration at low head speed, but goes away completely at higher speeds. As a rule, I look at the skids and the battery wire that hangs below the heli when hovering. If those things aren't noticably shaking/vibrating, I call it 'good enuff'...
I also have had 2 main shaft/gears where the gear was not perfectly centered on the shaft. One was not too bad, but the other was very bad.
Using stock parts, I just don't think it's possible to get the rotor on a BCP perfectly smooth and balanced, but you can get it close enough that it will fly quite well.
Something else to look out for is head dampening. If it's too loose, then your blades will likely lose their tracking at a certain head speed. This can often cause vibration/wobbling itself. I currently have 2 shims behind my O-rings, and still have this problem slightly. I am going to add 1 more shim on each side tonight to hopefully get rid of it completely...
I also have had 2 main shaft/gears where the gear was not perfectly centered on the shaft. One was not too bad, but the other was very bad.
Using stock parts, I just don't think it's possible to get the rotor on a BCP perfectly smooth and balanced, but you can get it close enough that it will fly quite well.
Something else to look out for is head dampening. If it's too loose, then your blades will likely lose their tracking at a certain head speed. This can often cause vibration/wobbling itself. I currently have 2 shims behind my O-rings, and still have this problem slightly. I am going to add 1 more shim on each side tonight to hopefully get rid of it completely...
09-10-2006 | 10:19 PM
#6
Senior Member
Joined: Aug 2006
Posts: 307
Likes: 0
Received 0 Likes
on
0 Posts
From: , CO
RE: cp vibrations
ORIGINAL: ct420
It has been my experience that all of the center hubs on the stock head are slightly warped. I've gone through about 6 or 7 of them now, and every single one has been very slightly warped. It does cause a slight vibration at low head speed, but goes away completely at higher speeds. As a rule, I look at the skids and the battery wire that hangs below the heli when hovering. If those things aren't noticably shaking/vibrating, I call it 'good enuff'...
I also have had 2 main shaft/gears where the gear was not perfectly centered on the shaft. One was not too bad, but the other was very bad.
Using stock parts, I just don't think it's possible to get the rotor on a BCP perfectly smooth and balanced, but you can get it close enough that it will fly quite well.
Something else to look out for is head dampening. If it's too loose, then your blades will likely lose their tracking at a certain head speed. This can often cause vibration/wobbling itself. I currently have 2 shims behind my O-rings, and still have this problem slightly. I am going to add 1 more shim on each side tonight to hopefully get rid of it completely...
It has been my experience that all of the center hubs on the stock head are slightly warped. I've gone through about 6 or 7 of them now, and every single one has been very slightly warped. It does cause a slight vibration at low head speed, but goes away completely at higher speeds. As a rule, I look at the skids and the battery wire that hangs below the heli when hovering. If those things aren't noticably shaking/vibrating, I call it 'good enuff'...
I also have had 2 main shaft/gears where the gear was not perfectly centered on the shaft. One was not too bad, but the other was very bad.
Using stock parts, I just don't think it's possible to get the rotor on a BCP perfectly smooth and balanced, but you can get it close enough that it will fly quite well.
Something else to look out for is head dampening. If it's too loose, then your blades will likely lose their tracking at a certain head speed. This can often cause vibration/wobbling itself. I currently have 2 shims behind my O-rings, and still have this problem slightly. I am going to add 1 more shim on each side tonight to hopefully get rid of it completely...
ditto
and ditto
09-11-2006 | 02:35 PM
#8
Thread Starter
Senior Member
Joined: Apr 2005
Posts: 562
Likes: 0
Received 0 Likes
on
0 Posts
From: milwaukee,
WI
RE: cp vibrations
what i have planned is that i will get a set of flat bottomed blades from jcs hobbies and the century up-grade mentioned in bladecprepair.com
do you see any issues with that? i know more blade grips will break, but id rater replace that instead of main blades.
do you see any issues with that? i know more blade grips will break, but id rater replace that instead of main blades.
09-11-2006 | 03:10 PM
#9
Senior Member
Joined: Feb 2006
Posts: 1,024
Likes: 0
Received 0 Likes
on
0 Posts
From: Ottawa, ON, CANADA
RE: cp vibrations
The only problem I see is that you may bend the main shaft before the blade grips break.I dont know how strong that shaft is but in the event that you have a crash bad enough to break the grips you may also bend the shaft. Then again you may never have a crash bad enough to do any of this damage. This is only speculation. It takes a LOT to break a blade grip. Ive had some pretty wild crashes in my learning and only ever broke 1 set of grips.
Ive looked at that shaft youre talking about online and Ive also thought about getting it. Only thing that sux is that if you do bend it then you have to order another 1 and wait till it gets in.
Ive looked at that shaft youre talking about online and Ive also thought about getting it. Only thing that sux is that if you do bend it then you have to order another 1 and wait till it gets in.
09-11-2006 | 04:46 PM
#11
Senior Member
Joined: Feb 2006
Posts: 1,024
Likes: 0
Received 0 Likes
on
0 Posts
From: Ottawa, ON, CANADA
RE: cp vibrations
Yah Im in Canada and for me to order it takes longer than it would for you. Otherwise Id probably use that shaft as well. My LHSs order like Thursday and get their orders the next Thursday. So if I order on Friday then I have a 2 week wait which is kinda BS.
09-11-2006 | 07:40 PM
#13
Member
Joined: Jul 2006
Posts: 70
Likes: 0
Received 0 Likes
on
0 Posts
From: San Ramon, CA
RE: cp vibrations
One of the tricks I read here which has helped me to determine if the wobble is the shaft is to simply take off the blades and then throttle up as you hold the heli. If it's still wobbling, then it's probably the shaft. If not, then it's the blades... If you have a bad shaft and replace it the wobble should be noticably gone without blades.
09-11-2006 | 07:52 PM
#14
Thread Starter
Senior Member
Joined: Apr 2005
Posts: 562
Likes: 0
Received 0 Likes
on
0 Posts
From: milwaukee,
WI
RE: cp vibrations
ill do that.
im still going to need to get a new pair of blades anyway....i found out to gard that stunt-hover switch..blades moved and hit sumthin hard, now the tips are busted.darn not much. just a leading edge is chiped, less then 1/4 inch on one, nuthin on the other.
its the shaft that is bent. also, where do you have your gain and perportional set at?
im still going to need to get a new pair of blades anyway....i found out to gard that stunt-hover switch..blades moved and hit sumthin hard, now the tips are busted.darn not much. just a leading edge is chiped, less then 1/4 inch on one, nuthin on the other.
its the shaft that is bent. also, where do you have your gain and perportional set at?
09-11-2006 | 08:11 PM
#16
Member
Joined: Jul 2006
Posts: 39
Likes: 0
Received 0 Likes
on
0 Posts
From: Chicago,
IL
RE: cp vibrations
I've been using the hardened shaft and century autorotation hub mod for a couple of months, and it has never bent, even after some spectacular idle-up crashes. While I have the wobble during spool-up, it goes away completely. So, "ditto", I guess, with a strong recommendation for the hardened shaft.
09-11-2006 | 08:15 PM
#17
Senior Member
Joined: Feb 2006
Posts: 1,024
Likes: 0
Received 0 Likes
on
0 Posts
From: Ottawa, ON, CANADA
RE: cp vibrations
I havent bent a spindle yet and had some pretty nasty crashes. Usually high speed flipovers though. But Im thinkin bout getting that hardened spindle for a spare though. Is it an exact replacement of the stock 1?? And do the stock grips and everything fit right on?
09-11-2006 | 08:17 PM
#18
Thread Starter
Senior Member
Joined: Apr 2005
Posts: 562
Likes: 0
Received 0 Likes
on
0 Posts
From: milwaukee,
WI
RE: cp vibrations
im sold on the shaft. im ordering the set tmm.
does anyone know about the centuary blastic main blades for the humming bird fp?
also, has anyone used a direct tail motor mod instead of the geared set-up?
does anyone know about the centuary blastic main blades for the humming bird fp?
also, has anyone used a direct tail motor mod instead of the geared set-up?
09-11-2006 | 08:18 PM
#19
Member
Joined: Oct 2005
Posts: 36
Likes: 0
Received 0 Likes
on
0 Posts
From: , WI
RE: cp vibrations
The best way to check for a bent spindle is to remove one main blade and turn the spindle using your 1.5mm hex wrench. If the other blade wobbles while turning the spindle, the spindle is bent.
09-11-2006 | 08:37 PM
#20
Senior Member
Joined: Feb 2006
Posts: 1,024
Likes: 0
Received 0 Likes
on
0 Posts
From: Ottawa, ON, CANADA
RE: cp vibrations
I used the DD before I went dual motors. The DD does work well and it will last a little longer than the stock tail but if you ere ever going to add a gyro I dont think it would have the power needed. But its still a better setup than the stock tail.
I use dual tail motors now and I wont change again. They dont even get warm after flying a whole 11V battery pack and the power they produce is great.
I use dual tail motors now and I wont change again. They dont even get warm after flying a whole 11V battery pack and the power they produce is great.
09-11-2006 | 09:57 PM
#21
Member
Joined: Jul 2006
Posts: 70
Likes: 0
Received 0 Likes
on
0 Posts
From: San Ramon, CA
RE: cp vibrations
That's a cool idea to check teh spindle via the hex nut.... that thing is a pain to replace...well really the shaft is a pain. I can take apart the CX in like 15-20 minutes. The CP always seems to take me like 1.5-2.0 hours to replace the main shaft. It's difficult to pull the bearing past the tiny hole in the shaft to get the old one loose...and getting the spindle stuff out and back is a pain too....
Any links on that hardened shaft/gear set for the CP? What's the cost... (I'm too lazy to go search for it right now myself...hahahah)
Any links on that hardened shaft/gear set for the CP? What's the cost... (I'm too lazy to go search for it right now myself...hahahah)
09-11-2006 | 10:08 PM
#22
Thread Starter
Senior Member
Joined: Apr 2005
Posts: 562
Likes: 0
Received 0 Likes
on
0 Posts
From: milwaukee,
WI
