Raptor^Norway

I have som problems with low freqency vibrations on my Raptor .30. The vibrations is apparent when I slow down the head speed. When I spin the headspeed up, the problem is not that significant, but when I reduce the headspeed the heli shakes really bad!

The main blades are in perfect balance, i have balanced out the flybar too! Also tried to change the 25% setting, both up and down, on my throttle-curve. (Got that tip from a website).

But I still have the bad vibrations on shut down.
I might also add that the heli is brand new, and never flown! Only done a little hovering with it.

Hope someone out there have just the tip I need!

Happy flying!

crash1953

sounds to me like maybe you have a bent main shaft or feather shaft .. it also could be that you have have a loose screw on the fly bar .. If it is the fly bar you will also have trouble keeping the blades tracking .another thing to check is the fan .. they can be out of balance ..

pirate man

check to make sure the main blades are not to tight. if they are they are probably not centrifugally balance. just loose the bolts about a 1/4 turn at a time to see if the vibes go away. hope this helps.

cowboysfan

Raptor^Norway

Hi, thanx for the reply!

The flybar should be ok, doublechecked it. Bent mainshaft and/or spindle is unlikely also...it's a brand new kit!!

I will try to loosen the main blades a little, maybe they are a little tight ;o) If that dosen't work, I'll have a closer look at the fan! But my problem is a LOW freq. vibration, don't think that is generated by the fan... I might be way wrong here, but it dosen't seem right.

I will let you know, until then; Fly Safe!

helihawks

Get the metal head block....

rapture

Here's a blade grip test:

Tighten the blade grips to what you think is pretty firm. Put the blades straight out as if you were just flying. Pick up the chopper and hold it nose down and give it a sharp jerk down then up. If the blades fall forward, then tighten them until they're just tight enough to not do so. If they're too tight loosen them until they just pass the test. Very tight blades would explain a vibration at lower head speeds but would straighten out when you hit 1800 RPM or so, depending on the chopper. Also, if they're too loose, they can 'scatter' when you're doing an auto, among other things.

My Raptor 30 shakes like crazy at a certain head speed (well before hover) but straightens right up quickly. There's a certain head speed that the chopper will vibrate at and that goes for all of them....you just have to find it and know where it is and avoid it. It's usually well before the machine gets light on it's feet.

If you have any bent or bad parts (not likely as mentioned above) the vibration will get worse as you increase the head speed.

qutrina

I am having the same issue. However, my only occurs at a certain throttle setting.

For instance, approximately 40% out/up nearly 1/2 stick the chopper will make this wierd sound and start to shake as if it was doing the butt dance. However, once you are even slightly below 40% or above the SHAKING stops. It does not occur in hovers, 3D flights, or any other time. Only when reducing the throttle; in other words, transactioning through this particular throttle settings. However, if you just blow past when reducing or adding power it will not shake. The best way that I can explain this shaking is when their is just enough power to make the helicopter light on the skids and give the cyclic enough control to actually bank and tilt the helicopter when it is still on the ground. If it is up in the air ... same difference. Overall very annoying.

If anyone can help please let me know.

Setup is Raptor V1
Occurs both with TT39 and OS 32 Max engines
Carbon 550 blades
NEW KIT .... JUST PUT A NEW CLUTCH IN JUST TO MAKE SURE (didn't resolve the issue)

One thing I caught just a few minutes ago is when I manually turn the clutch bell by hand (of course when the chopper is off), I can hear a scratchy sound at a certain point when rotating the clutch bell.

My guess is that the clutch my not be even and slightly rubbing up against the clutch liner ????

If this is the case will it wear down in time or will I have to rip this thing a part :-( ... If so as in ripping it apart, I am going to turn this thing into a Raptor 40 by putting a raptor 50 boom on it 580 blades, and (maybe the 8.5.1 gear ratio) may not need the gear once putting the bigger boom and stuff on it, because it may help. I run the TT39 engine right now and that thing has a ton of power for this Raptor 30. Put it like this, the blades/engine does not slow down in a max climbout with 10% of pitch. (or I may consider a governor) any help with this issue woudl be greatly appreciated.

Idle up 0(Normal) -7 / 0 / 10
Idle up 1 ... -10 / 0 / 10
Idle up 2 ... -9 / 0 / 9
Pitch ranges

Thank you in advance for any suggestions and help

Furyflyer2

My Feedback: (117)

Either your to lean and the engine is overspeeding.Or the auto clutch is slipping and disengaging. The start shaft is not supported very well and I found it necessary to add a third bearing,the result was a much quieter running heli .

Raptor^Norway

qutrina; looks like we have the same problem... My vibs will also reduse to nothing when i reach hover. And they don't occur until I reach a certain head speed. I have not tried to fly it yet, not to happy about those vibs.

I will try to figure out some more tomorrow (thursday). e.g. to rapidly reduse the throttle on the way down. Chek the blade grips etc.

I'll keep you posted!

luckystryke1

Hey all... I have a Raptor 30v2, I have similar, although not as severe problems as you guys are talking about. Mine does this low frequency vibration when I first begin to spool up, by the time it is light on it skids, all vibs are gone. Here are my observations: It seems as if all of us (raptor 30 owners) are having a very similar problem. It is always a low frequency vibration. This low frequency vibration is DEFINITELY being caused by some small imbalance on the main rotor head or the blades. I'm running the stock woodies, and they are damned near perfectly balanced. Wait...I just had a stroke of genius!
Check this out..... When you go to the field, before your first flight, what do you always do???? You take the main blades out of the foam blade holder (which is mounted on the boom), then you unfold them untill they appear to be exactly 180 degrees from each other (perfectly level looking from the top down). Now, keep in mind that there are lead weights at the ends of the blades. If either blade was off just a fraction of a fraction of an inch, then there would be a vibration that has a frequency the same as the rotor speed (which is spooling up). When the rotor speed gets high enough so that the centrifugal force that is exerted on the blades will straighten them perfectly, the blades are straightened and the vibration stops!
Well I can guarantee that that is what is going on with my rappy, and of course there isn't much that can be done about that. I know that this is the case with mine because, there is always that vibration when I first spool up, then when I'm running low on fuel and it's time to land, as the blades slow down the vibration never returns, because the blades have been pulled out to a perfectly straight position. Does this make sense to you guys?

luckystryke1

Tell me this guys: Your vibration occurs on spool up correct? Does it return after the end of the flight when you spool down ??? If not, then the above may be an explanation for you.

crash1953

Let me give you another thing that happened to my 60 v2.. I was having the same low freq vibration problems and it just kept getting worse ..I looked all over trying to find it .. I finally decided to tear it down and do a thorugh look at everything .. I still didnt find anything till I was putting it back together .. I found the bearing on the end of the seesaw was shot and the bearings werent far from being thrown out .That would allow the flybar to go out of track untill it got to speed .. but it wouldnt show at the low check speeds I was using on the ground . I changed that and all was fine again .. Just something to think about guys.

rapture

Here's my $0.02

This is the best way I can think of to explain it:

The shaking is basically at a harmonic to the head speed. The chopper body oscillations occur at a certain head speed and this varies greatly depending on blades, engine, load, blade weighting etc etc. What happens before it starts and after is that the vibration cancels itself out. It's hard to explain but every chopper I've seen will do it at some head speed or another, but the 'dances' are less with larger machines with heavier blades.

If you're just at hover speed (chopper is just about to lift off) and you drop the throttle suddenly, then engine should return to idle almost right away. If delays and does a ding...ding...ding...ding and returns to fast idle over several seconds, then it's probably lean on the mid range and this can cause overspeed of the head when you bring the chopper in after some idle up flying. This can cause another dance, but it stops quickly since the blades turn down through it. Another reason for this 'overspeed' is not enough pitch at mid throttle and that can cause vibrations too.

:thumbup:

qutrina

Thanks for the ideals. So far the bearing check is new to me. All of the other suggestions and concepts I tried. Here is the bad shake that I can reproduce at any altitude:

For instance let's say I am at any altitude up and the air. When I bring the throttle back approximately 40% (out) right below 1/2 stick this is when the shakes.

With the slightest increase or decrease in throttle, the shakes stop.

Is there any place that I can obtain an affordable RPM gauge reader for the helicopter? Ha, yeah right something affordable in the world of RC helicopters. However, I think I may need one to help tune this engine correctly unless someone knows a good method to make sure that the right amount of throttle is being used. My pitches are listed in the prior theads.

Thanks for the good tips.

crash1953

If it will do it in the air too ,you might have some bad or worn out flybar dampeners .. or they might just need to get some lube on them ..It sounds to me like the main blades are going out of track a little .. Try to get some one else to watch the blades real close in a hover and try to get it to do the vib thing .. Also make sure all the screws are tight on the head .. If any of them are loose or the linkage is binding ,even a little and you will get weird vibrations at different headspeeds.One thing my rappy 30 likes is a hight headspeed too ..

qutrina

I know that it is not the blades coming out of track because I watch them. However, the shaking is like this if you imagine sitting in your car and punching (or stepping fully on the gas peddle rapidly several times) until you stop. From there, the torque of the car make it shake, move, rise up, and/or pull to one side. It like the chopper revs itself up ...lmao :stupid: I am about go out and fly it and see if I can determine the issue more in detail. I will lube up the chopper, although it is only a 3 months old. This issue just started about 3 weeks ago ... all when a clutch started to break ... kept flying it until the clutch went bad/broke completely. From there, replaced the clutch and the problem seem to went away; however it came back. Even now with a new clutch it still hunts the chopper.

Chopper needs to go to church or something.

By chance, you know who sells tachometers that are not an arm and leg.

qutrina

If I am not mistaken no auto clutch installed. I did not upgrade or add anything like that. I could be wrong, but all the clutch bell, main spar gear, and etc are stock items.

__________________________________________________ __
HERE ARE THE RESULTS OF TONIGHTS FLIGHT:
__________________________________________________ _
Drum Rolls …............

After readjusting my throttle and mixture when making the transaction between the throttle the shaken was still there. However, as I kept doing it, it diminished to the point where it was hardly even a factor. However, when I went to Idle up 1 (-10 / 0 / 10) the shaking was started to revert. However, after I kept doing the throttle changes it appeared to diminished. Going to idle up 2 same pitch carve with the addition of the V curve no problem. More so, I was happy not to hear the engine over speeding when performing a decent. (it was so tempting to perform a tumble, but I will run another ½ gallon through the engine before doing so).

After the flight of thinking that, things are starting to return to normal, I think the hidden problem is starting to show. I do not know if this is major, minor, or nothing at all. Obviously, with wishful thinking I hoping it will be something simple.

So after the flight, for some reason I decided to turn the main blades and I heard this sand paper sound coming from the clutch bell. However, there is hardly any resistance; the blades still spin very freely. From there, I turn the clutch bell manually in the direction that the blades would not spin and the scratchy sound was still there. I am wondering if the clutch liner is causing this sound and if so will it be shaved down to the right size buy the clutch? In addition, could the cold weather I have cause this issue by causing the clutch bell to contract tighter around the clutch? If so, however would the clutch contract as well, but most likely the clutch is more resistant to contrasted compared to the clutch bell and/or liner?

Temperature outside was 32F with lots of humidity 90% and Windy … COLD WIND 6 -- 18MPH gust to 22 average is 10-14. Unfortunately, the last 5 tanks of fuel regarding this issue posted in the area threads, the temperatures has been in the range of 15 – 27F. Burrrrr Good things for Radio Gloves

After the chopper, thaws out I will turn the clutch bell to determine if it is back to normal or if this is my problem or new problem.


Thanks

extremeflying

My Feedback: (7)

i have a shaking problem with my 30 v1 it shakes like crazy blades r good tried balancing it and still shakes.checked the grips and the main shaft both good. so what now ? lean engine ? i tuned it in the nice and but flew it on the cold day.

crash1953

Extremeflying ,What kind of blades you using ?How did you try to check the balance ?You have any hard landings??crashes? ..I would check the head over real good ..Flybar spindle, main shaft paddles even on the flybar.

qutrina

I took the helicopter out and flying performed a tumble and roll. I could not get a good fill for the new engine yet, because the wind was 20 - 25 mph ... and it keep disturbing the helicopter more so me. However, after the flight, scratchy sound was gone.

The shaking was a little bit in the beginning and basically went an away by end of flight. In addition, I did turn my head speed down slightly at 3/4 stick. Now the helicopter just starts to get light on the skids when I am at 71% out and at 75% out (3/4 stick) it hovers). In addition, wonder if this had something to do with the clutch wearing evenly. Whenever I had this helicopter build, we had to sand the clutch liner down so that the clutch would fit in correctly and allow free movement of the rotor blades. I think my shaken is/was clutch liner related. The spindle shaft turns freely; however, I will give it a quick jiffy lube job just in case.

As mentioned above I just changed 3/4 stick from 60% to 58.5% - 59.0% and middle stick to 37.5% perhaps this may be helping as well. I just go to the throttle curve setting in your email reply suggestion. When I first put the engine is I did have 50% for middle. Based on my old OS32 specs it was 0, 25, 50, 75, 100, but I did notice I needed to change it right away when I put the TT39 engine. The head speed was just too high; however, the first 3 flights were playing around with the throttle curve. I should say, I am still messing around with them, because now I want to find the optimum settings for idle up 2 to perform rolls and tumbles

(I am at 0 degree of pitch for 1/2 throttle and 5 degrees of pitch for 3/4 stick)

Now my throttle curves are the following:

Idle up 0 (normal) 0 / 23 / 37.5 / 59 / 91 (IF I put point 5 up to 100% or even if I go up to 94% it sounds like the blades are over speeding during climb out. Plus when transaction from full power to however, it takes a few seconds for the blades to calm down.)

Idle up 1 15 / 23 / 37.5 / 59 / 91

Idle up 2 91 / 62 / 51 / 62 / 91 (still experimenting with idle up 2) waiting for a clam day without wind. I may change the point 0 and 5 from 91 to 94 if I notice the engine bogging down. Is that a good ideal or bad? I thought it would be like power to spear, hitting the turbo boost button or something like that.

The cyclic mixing did help out a lot with the OS 32 max; however, the OS 32 was just being max out too much. I would let you know how it works with the TT39. I did not change the setup. I have the same settings still 30% aileron to throttle and 30% elevator to throttle.

No, the helicopter has not been crashed or in any hard landings.

Thanks for the helpful tips and suggestions. One day, I will have some knowledge with this thing.

extremeflying

My Feedback: (7)

ok i think i've solved my problem. last night i took the blades out for a check. guess that i found a cut on the blade. the plastic cover has been cut so i think this is the reason it was shaking i replaced it with a set of Jr blades. do u think it still would shake ?

crash1953

Make sure you balance them first .. I know they are suposed to be balanced ,but I dont think I ever had a set of woodies that was hardly even close ..Thats why I just gave u[p on woodies and went to carbon or fibreglass blades .. They are much smoother and balanced better and they dont change or warp with the weather.

extremeflying

My Feedback: (7)

i've flown the rap w/o balancing the blades and they work fine til this plastic thing riped off

qutrina

Update regarding shaking:

Overall, after spending 2 tanks of fuel tweaking the engine with experienced pilots we determined that the shaking was being caused by the low end mixture settings.

The best thing that I can suggest is to have patience and a lot of fuel.

We first started out with 3 turns out on the high-end needle value setting from lean as depicted in the manual. From there, we turned the low needle value completely lean and worked it out until proper low end idle was achieved. Overall, the low end should not be too lean so that overheating and over speeding does not occur. In addition, the low end cannot be to rich or the engine will not develop enough power during low throttle curve settings (especially in idle up 2) and easy flooding will occur. Note whenever performing autos the helicopter should not shake or display any low end or high-end issue in lieu of shaking.

We determine it is not the clutch, although I should replace it or try to get it shaved down more evenly. Overall, when the temperatures increase the clutch should wear fine, unless it the shaved down area is too much.

For reference:

Here are my throttle curves using a JR 8103 radio with the TT39 engine with the 8103 radio travel range set to 100% resulting in full traveling range of throttle arm. (note you may need to adjust the ball links to acquire the same travel range with these settings.)

I prefer flying with a slightly higher head speed for hovering due to better cyclic control, especially when wind is not being your friend.

This setup for normal flying mode achieving 1720 RPM
Throttle points 0 / 25 / 44 / 58 / 91.5
Pitches are -7 / 0 / 10

(use 100% at your discretion. This setup is for a Raptor V1, Mavrikk 550 Carbon blades and upgraded/ace muffler, KSJ fly bar and tail rotor paddles, 30% cool power, and with the TT39 engine. It is easy to over speed even with 10 degrees of pitch when performing a full power climb out. Perhaps this will not occur with the heavy wood blades, stock tail and fly bar paddles.

This setup for idle up 1flying mode achieving 1750 RPM]
Throttle points are 24 / 27 / 44 / 59 / 91.5
Pitches are – 10 / 0 / 10

This setup for idle up 2 flying mode achieving 1900 RPM
Throttle points 92 / 62 / 50.5 / 62 / 92 as depicted above you can use 100% if you notice that you are bogging down the engine with aggressive 3D maneuvers. However, I use mixing such as aileron and elevator to throttle mixing to compensate for engine performance and loading. Therefore, at this time, I have no need to increase to 100% because, the mixing allows an increase in throttle without changing the blade pitch; therefore, allowing the blades to easier maintain the RPM during demanding power maneuvers.
Pitches are -9 / 0 / 10

NOTE: IF USING 8103 radio and some others , you may need to perform a modification on your throttle travel ranges, sub trims, and position to keep the throttle arm from binding with using mixing. This technique can be referenced on the raptor techniques website. Another option is the spring loaded servo saver. Before flying when using mixing check and make sure that the servo is not binding when, apply elevator and aileron mixing for BOTH IDLE UP 1 AND 2.

Steve Landron

Interesting, My Raptor 30 V2 has the same vibration (dancing) problem spooling up and down. My resolution was to throttle up and down quickly through that rpm range where vibration is worst. I have had the problem with both the OS engine (.37) and Thunder Tiger Pro (.39). My helo has never been crashed. When I get home off of deployment, I plan on replacing the stock wooden blades with a set of nice carbons, also read elsewhere in the forum where someone suggested using silicon grease on the Dampers. Something I plan on trying as well.

Steve
[8D]