RunRyder RC
WATCH
 2 pages [ <<    <    ( 1 )     2     NEXT    >> ] 2067 views Post Reply
Home✈️Aircraft🚁HelicopterHIROBOHirobo SDX › Help tracking down a tail vibe after a rough auto
03-30-2010 06:57 AM  10 years ago
Topic Vote0Post 1
Tron

rrApprentice

Morgan Hill, CA

MyPosts All Forum Topic
Help tracking down a tail vibe after a rough auto
History: Had a rough emergency auto landing and busted one blade. Little headspeed left on landing and the blade must have hit the dirt since the tail boom was fine with no signs of impact. The heli was sitting upright when I got to it.

Flight 1: I replaced the spindle (that thing is beefy; no sign that it was bent but replaced with new anyway) and a head linkage and flew again. The tail just didn't look smooth and still like before. More of a blurry vibration. Main rotor as smooth as before with the new spindle and another set of previously used carbon blades.

Flight 2: So I replaced the tail shaft and hub. Seems to help a bit though vibration still there as evidenced by the fuel swishing around and foaming up (I didn't notice in flight #1). I was running the head speed around 1950 before but the vibes get crazy if I get that high now. Vibes increase with rpm.

The tank is shaking so badly, the black rubber mounts are wearing out and leaving small blace specks all around the tank area. The fuel is so foamy, that my engine is running like crap now even with the rev max. The engine is running hotter than before but I initially attributed that to the fuel foaming. I did have to richen the needle (4 clicks, didn't seem to help) and the glow plug blew. I replaced with a new plug and then the engine won't start at the normal throttle idle postion. Had to advance the throttle to get it started and hold an idle.

Could it be the Hyper 50 bearing is going out and causing rough running?

I'm going to remove the back plate and check the inside of the hyper this weekend.

Any other suggestions on what to look at to track down this vibration problem?
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
03-30-2010 10:39 AM  10 years ago
jbiter

rrKey Veteran

Sebring, FL

MyPosts All Forum Topic
Center hub or main shaft bent?
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
03-30-2010 11:05 AM  10 years ago
Against Gravity

rrVeteran

Pottstown PA

MyPosts All Forum Topic
Runout
Pull the Engine and re check the run out on the drive line. The SDX can be very sensitive to anything getting out of balance.
Re check your gear mesh also, Hopefully you will find it
AG
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
03-30-2010 01:43 PM  10 years ago
ttrip06

rrApprentice

Central Pa

MyPosts All Forum Topic
I am surprised you did not bend the main shaft if you broke one of the blades. Check Main Shaft Bearing and thrust bearing both head and tail.

Trip.
Tim Tripoli

Team Futaba, Rail Blades
Team Crash
ProggressiveRC
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
03-30-2010 03:26 PM  10 years ago
MRC-Hirobo

rrKey Veteran

Edison, NJ

MyPosts All Forum Topic
I would say main shaft too.

Quick story.

I put an OS 55 in my SDX and from the first flight i had a vibration that literally was loosening bolts on my helicopter.

I spent a while searching for the problem. I replaced everything and i mean everything, all the shafts all the bearings, Balanced everything 5 times.

I don't think I'm exaggerating when i say i must have had the engine in and out of the helicopter a dozen times.

Long story short.

It was the brand new bearing in the New 55. I was not thinking clearly.

It never occurred to me that the bearing could have been bad because it was a BRAND NEW engine.

I think the 55 is a great engine and I love OS and am not mad at them for the problem. I guess this was just a lesson learned and I know thing happen.

Needless to say, with the new rear bearing in the helicopter. I was back in the air and replacing all the shafts again this time due to crashing!.
MRC Host
SHARE  PM  EMAIL  HOMEPAGE  GALLERY  Attn:RR  Quote
03-31-2010 03:56 AM  10 years ago
Aaron29

rrProfessor

USA

MyPosts All Forum Topic
Only vibes I ever had that weren't bearing or tuning related was the clutch start shaft slightly bent from a crash.

Replaced it and it was smooth overnight.

Can you dial indicate it?
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
03-31-2010 06:58 AM  10 years ago
Tron

rrApprentice

Morgan Hill, CA

MyPosts All Forum Topic
Fellas,

Some good suggestions. Guess I'll try the main shaft next as it was most often suggested, is quick enough, and it's a rotating shaft I haven't replaced yet.

I opened up the engine backplate and didn't see anything out of the ordinary. No bits of metal or any signs that the rear bearing is going. Just nice red coolpower tinge on the parts.

I must admit, I'm a bit surprised that the rough landing could bend the main shaft, starter shaft, center hub, etc. Practically no headspeed left at the bottom and landed sitting on the skids. Same main shaft in my post crash flights and the main rotor looked great.
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
03-31-2010 01:40 PM  10 years ago
TMoore

rrMaster

Cookeville, TN

MyPosts All Forum Topic
Make sure the starter coupling is tight. Not being tight can cause a nasty vibration.

TM
Part 107.
The only ZERO flight hour certificate in the world.
It's like getting a driver's license without the driver's test.
SHARE  PM  EMAIL  HOMEPAGE  GALLERY  Attn:RR  Quote
03-31-2010 08:11 PM  10 years ago
rudyy

rrElite Veteran

E. Amherst, NY

MyPosts All Forum Topic
1) Is your mainframe damaged? A damaged mainframe will cause vibration.

2) have you tried replacing the tail blades? Maybe they are out of balance.

3) check you belt tension and make sure it is not loosened

4) check your engine bolts to the frame and make sure they are not loosened

5) check your center hub and make sure it is not bent and is firmly secure to the main mast.

6) check your tail rotor spindle and make sure it is not bent
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
04-02-2010 12:26 PM  10 years ago
RussJ

rrApprentice

lockport, new york usa

MyPosts All Forum Topic
One of the members in our local club just had a similar experiance like yours. He had a bad vibration and could not track it down. He went through the whole helicopter. It turned out his almost brand new 55 engine had a bad bearing and that was the cause of it all. That is something I never would have guessed. I am not saying that is your problem though. The cause of your problem is most likely due to the hard landing you had. I had a vibation once and it turned out my paddles were not properly aligned. I re-aligned them and I was good. Vibrations can be tricky to track down. Hope you track down the problem soon.
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
04-03-2010 05:27 AM  10 years ago
Aaron29

rrProfessor

USA

MyPosts All Forum Topic
Russ, when you add your field mates story to this one...
Long story short.

It was the brand new bearing in the New 55. I was not thinking clearly.

It never occurred to me that the bearing could have been bad because it was a BRAND NEW engine.

I think the 55 is a great engine and I love OS and am not mad at them for the problem. I guess this was just a lesson learned and I know thing happen.
Hmmm.

Hyper 50 woes hitting the 55 or is it too early for me to start a rumor?
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
04-07-2010 03:09 AM  10 years ago
Jadesfire007

rrNovice

Richmond, Virginia

MyPosts All Forum Topic
I have got to go with the Main shaft idea. it may look straight to the eye but find a FLAT metal surface like a table saw and see. Had a vibe like yours once and it turn out mainshaft was BARELY bent.
SHARE  PM  EMAIL  Attn:RR  Quote
04-12-2010 03:07 AM  10 years ago
rudyy

rrElite Veteran

E. Amherst, NY

MyPosts All Forum Topic
Any findings?
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
04-13-2010 07:35 AM  10 years ago
Tron

rrApprentice

Morgan Hill, CA

MyPosts All Forum Topic
Fellas,

Sorry for the delay. Just wrapped up my spring break trip so I'm back to heli business again.

I've got to put an order in for the main shaft. Thought I had one in the last order but turns out it was only spindles and flybar. I actually tried to get to a hobby shop in vegas last week but the shop was still pending city inspection in their new location and wasn't open for business.
Should have the part by end of week and ready to test this Sunday, weather permitting.
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
04-27-2010 07:35 AM  10 years ago
Tron

rrApprentice

Morgan Hill, CA

MyPosts All Forum Topic
Update!

Replaced main shaft and made a test hover with it. No improvement and now I've replaced the main shaft, spindle, tail shaft, and tail hub with no success.

However, I got some more confirmation that it might be the engine/bad bearing because it was a pain to start and I had to open up the throttle a lot more than normal to get it to start and maintain an idle. A brief hover about a minute long and the engine is hot.

Last time out, I blew a glow plug and the engine was running hot too which I thought was due to the fuel foaming but now could be the initial indication of the hyper going south.

Anyway, next step is to get a new engine and/or replacement rear bearing. Either way, the engine has to come out for a more detailed inspection. Removing the backplate last time didn't show any debris but then again I couldn't see the rear bearing as the crankshaft obscured it.
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
04-27-2010 08:35 AM  10 years ago
Aaron29

rrProfessor

USA

MyPosts All Forum Topic
Did you ever dial indicate your clutch shaft?
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
04-27-2010 02:30 PM  10 years ago
JuanRodriguez

rrProfessor

The Villages, Florida

MyPosts All Forum Topic
Last time out, I blew a glow plug and the engine was running hot too which I thought was due to the fuel foaming but now could be the initial indication of the hyper going south.
Before tearing anything down or replacing motors, I would thoroughly go over your entire fuel system...... it sure sounds like you have an obstruction somewhere.....

I would remove the needles and back-flush the carburetor..... Also, replace ALL of your fuel lines and make sure that the nipples on your fuel tank are clear of any manufactoring slivers of plastic that may have shifted around and now causing you grief.....

If you have a fuel filter between the tank and carb, either replace it with a new one or remove it altogether (at least for testing purposes)......

Although it could be more serious (like a bearing, etc,) sometimes the siplest things are overlooked.......

I hope these suggestions are useful and that your motor is not yet ruined......
Been there, done that and old enough to know better.....
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
04-28-2010 12:29 AM  10 years ago
Tron

rrApprentice

Morgan Hill, CA

MyPosts All Forum Topic
No, I have not dial indicated the clutch shaft. It's possible as it is a rotating shaft that hasn't been replaced yet.

I didn't dial indicate anything when building the new kit and it flew silky smooth right out of the box. I doubt the hard landing could bend it as no frame damage was found.

Fuel System check:
I did some of this while replacing the main shaft (ordered me a fancy Hirobo header tank with the main shaft!). Checked for obstruction in all lines and tank nipples by blowing through and no problems.

Before the engine tear down, I'll back flush the carb/needles and do a quick hover test to see if that helps.
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
04-28-2010 12:53 AM  10 years ago
JuanRodriguez

rrProfessor

The Villages, Florida

MyPosts All Forum Topic
Checked for obstruction in all lines and tank nipples by blowing through and no problems.
That's not a good enough "check".... You need to take things appart and VISUALLY check for any "flash" that may have been left behind during the manufacturing process..... "Flash" in a metal clunk cost me an OS Hyper motor before I discovered the problem.... too late, unfortunately....

The only way to "check" your fuel lines is to just replace them ! That's the cheapest way. Your "blowing" method is just not good enough..... In actual use, fuel lines that are "questionable" may start to collapse causing your fuel mixture to become "lean".... do it too many times will cost you the motor....

Bottom line, there are NO shortcuts !!
Been there, done that and old enough to know better.....
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
04-28-2010 11:55 AM  10 years ago
Against Gravity

rrVeteran

Pottstown PA

MyPosts All Forum Topic
Check the cluch shaft
As I said before, Even though you frames are OK, they will flex allot in a crash.
When they flex they put stress on every rotating part, especially your clutch stack. Believe me I have learned this the hard way.
AG
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
WATCH
 2 pages [ <<    <    ( 1 )     2     NEXT    >> ] 2067 views Post Reply
Home✈️Aircraft🚁HelicopterHIROBOHirobo SDX › Help tracking down a tail vibe after a rough auto
Print TOPIC

 11  Topic Subscribe

Wednesday, October 28 - 3:14 am - Copyright © 2000-2020 RunRyder   EMAILEnable Cookies

Login Here
 New Subscriptions 
 Buddies Online