Once again about vibration.

nen77 · 10-13-2011, 12:59 PM

i'm making this post for a friend of mine . he stay away from any heli comunity, we visit from time to time.

i asked him to make a movie with the problem , and i sugested a solution, wich i wil not mention here - i wait to see if other offer same solution.

- set-up

-yamada engine
- radix blades
- torque tube upgrades.
-first time was equiped with os 91 engine , same vibration

replaced : clutch (all parts), new rotor head (he bought a new kit for spares)

video..

YouTube

hookmaker · 10-13-2011, 01:44 PM

Engine looks and sounds way too lean for me. My own YS engine vibrated a lot when lean - so much that my CGY750 FBL controller governor failed to work corectly.
/Henrik

Mercuriell · 10-13-2011, 03:33 PM

I'd agree with Henrik the engine too lean on that - have to check and double check pinion, engine mount, dampers as per manual and videos in Technical Tips. ALso check the tail from behind, if the blades are out of track it may be an offset tail rotor hub - a few escaped the factory not quite square (since remedied). Let us know how you go !

nen77 · 10-13-2011, 03:51 PM

thank's for fast answer , i will call my friend tomorow and i will tel him to open the middle ,glad that i asked , motor sound strange to me but my advice it was to lean the engine.

HeliBenj · 10-13-2011, 04:38 PM

+1, this engine sounds very lean, also noticeable in the smoke flow that gets thinner as the RPM goes up.
I also had strange vibration with my former engine when running lean. The Srimok will make a bad tune and used engine bearing quite visible.

hookmaker · 10-13-2011, 04:53 PM

Yep, start by richening the middle needle.
/Henrik

thefrog · 10-14-2011, 02:38 AM

Something I've found is that my heli doesn't like certain headspeed - at 1800rpm it's all over the place. The vibe logs show low overall vibration but the way the heli shakes and twitches is quite horrible. I've ruled out tuning - this is with two different motors and setups from factory rich to spot on tune.

I run 1850 rpm in normal mode and 1930 in idle up. This is with an OS motor and 8.17 gear ratio.

HeliBenj · 10-14-2011, 02:47 AM

No, I believe with the YS you should start with the mid in that condition. If hover smoothes out then check high

XBOY · 10-14-2011, 09:09 AM

I have many times it was a perfect test

nen77 · 10-14-2011, 01:59 PM

i called my friend , and told him to open the needle's .after opening no improvement(4 click's on both needles)he says that the sound of lean engine is caused by the fuel with 15% nitro.
trick he also aplied from tehnical tips , new dampners to engine , and clutch dampners set-up after indication from video , new tail rotor (from spare kit ) new tail blades.

my opinion is that engine still can be to lean.
he also asked me to mention a thing : in video is not so well presented the vibration is more sideways in the head wich look's to be transmited to the tail...

HeliBenj · 10-14-2011, 02:19 PM

Sorry not buying the 15% thing. I run 15% and none of my engines ever sounded like that (YS91SR, OS91HZ, HZ-R 3D).

Now maybe the engine is not the main reason here, but it can't be good either. Any idea of the temperature being run on the head?

nen77 · 10-14-2011, 02:34 PM

70-75 celsius 158-167 fahrenheit...

i can not advice in nitro engine's i crashed 3 os 91 engines .i have a topic in 700n area...found the couse after 1 year , 3 engines and 5 engine sets..caused by a molding problem of fuel tank.

also is hard to transmit your info to him, also he is tryng to "fix this problem" from a long time.

10-13-2011, 01:44 PM	#2
hookmaker Registered Users My HF Map location Join Date: Jun 2006 Location: Copenhagen, Denmark	Engine looks and sounds way too lean for me. My own YS engine vibrated a lot when lean - so much that my CGY750 FBL controller governor failed to work corectly. /Henrik __________________ Hookmaker Kasama Srimok 90, Kasama Srimok 90E, JR Vibe 90 SG, JR Venture 90, JR Vibe 50 3D V-bar, Bergen Intrepid Gasser, Vision-SX 90 (x 2) MSH Protos "Monsterheli", HDX-450

10-13-2011, 03:33 PM	#3
Mercuriell HF Support My HF Map location Join Date: Sep 2006 Location: QLD, AUSTRALIA	I'd agree with Henrik the engine too lean on that - have to check and double check pinion, engine mount, dampers as per manual and videos in Technical Tips. ALso check the tail from behind, if the blades are out of track it may be an offset tail rotor hub - a few escaped the factory not quite square (since remedied). Let us know how you go ! __________________ John

10-13-2011, 04:38 PM	#5
HeliBenj Registered Users Join Date: Jan 2009 Location: Provence, France	+1, this engine sounds very lean, also noticeable in the smoke flow that gets thinner as the RPM goes up. I also had strange vibration with my former engine when running lean. The Srimok will make a bad tune and used engine bearing quite visible. __________________ Ben Goblin 500 IKON w/ gov, Quantum 4115-1200, Hitec 5245, BLS251 DX8, RF6

10-13-2011, 04:53 PM	#6
hookmaker Registered Users My HF Map location Join Date: Jun 2006 Location: Copenhagen, Denmark	Yep, start by richening the middle needle. /Henrik __________________ Hookmaker Kasama Srimok 90, Kasama Srimok 90E, JR Vibe 90 SG, JR Venture 90, JR Vibe 50 3D V-bar, Bergen Intrepid Gasser, Vision-SX 90 (x 2) MSH Protos "Monsterheli", HDX-450

10-14-2011, 02:38 AM	#7
thefrog Registered Users My HF Map location Join Date: Feb 2011 Location: South Africa	Something I've found is that my heli doesn't like certain headspeed - at 1800rpm it's all over the place. The vibe logs show low overall vibration but the way the heli shakes and twitches is quite horrible. I've ruled out tuning - this is with two different motors and setups from factory rich to spot on tune. I run 1850 rpm in normal mode and 1930 in idle up. This is with an OS motor and 8.17 gear ratio. Last edited by thefrog; 10-14-2011 at 02:59 AM.. Reason: Corrected by Ben

10-13-2011, 03:51 PM	#4
nen77 Registered Users Thread Starter Join Date: Aug 2007 Location: Romania	thank's for fast answer , i will call my friend tomorow and i will tel him to open the middle ,glad that i asked , motor sound strange to me but my advice it was to lean the engine.

10-14-2011, 02:47 AM	#8
HeliBenj Registered Users Join Date: Jan 2009 Location: Provence, France	No, I believe with the YS you should start with the mid in that condition. If hover smoothes out then check high __________________ Ben Goblin 500 IKON w/ gov, Quantum 4115-1200, Hitec 5245, BLS251 DX8, RF6

10-14-2011, 09:09 AM	#9
XBOY Registered Users Join Date: Feb 2011 Location: Hong Kong	I have many times it was a perfect test

10-14-2011, 01:59 PM	#10
nen77 Registered Users Thread Starter Join Date: Aug 2007 Location: Romania	i called my friend , and told him to open the needle's .after opening no improvement(4 click's on both needles)he says that the sound of lean engine is caused by the fuel with 15% nitro. trick he also aplied from tehnical tips , new dampners to engine , and clutch dampners set-up after indication from video , new tail rotor (from spare kit ) new tail blades. my opinion is that engine still can be to lean. he also asked me to mention a thing : in video is not so well presented the vibration is more sideways in the head wich look's to be transmited to the tail...

10-14-2011, 02:19 PM	#11
HeliBenj Registered Users Join Date: Jan 2009 Location: Provence, France	Sorry not buying the 15% thing. I run 15% and none of my engines ever sounded like that (YS91SR, OS91HZ, HZ-R 3D). Now maybe the engine is not the main reason here, but it can't be good either. Any idea of the temperature being run on the head? __________________ Ben Goblin 500 IKON w/ gov, Quantum 4115-1200, Hitec 5245, BLS251 DX8, RF6

10-14-2011, 02:34 PM	#12
nen77 Registered Users Thread Starter Join Date: Aug 2007 Location: Romania	70-75 celsius 158-167 fahrenheit... i can not advice in nitro engine's i crashed 3 os 91 engines .i have a topic in 700n area...found the couse after 1 year , 3 engines and 5 engine sets..caused by a molding problem of fuel tank. also is hard to transmit your info to him, also he is tryng to "fix this problem" from a long time.

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