RunRyder RC
WATCH
 2 pages [ <<    <    ( 1 )     2     NEXT    >> ] 1877 views POST REPLY
HomeAircraftHelicopterAlignT-REX 600N › Tail shudder with Novarossi .57
05-16-2011 03:32 AM  7 years agoPost 1
jasonrusso

rrApprentice

Haverhill, Massachusetts

My Posts: All  Forum  Topic

Over the winter I swapped out .50 OS Hyper for a .57 Novarossi Rex. I have only taken it out a couple times this year (the weather has been sucking) but when it is in a hover (about 2100 headspeed) the tail has a non-rythmic shudder that can be pretty violent. If I slow the engine down, it goes away, but I like to fly in idle-up at the high headspeed. If I give it a full collective climb, the tail is steady. I swapped the clutch and fan assembly from the old engine, and I don't remember having this problem with the .50. The engine has an OS carb on it, which is supposed to be easier to tune (I have the Rossi carb). I am running a JR770 3D gyro.

PM  EMAIL  GALLERY  Attn:RR  Quote
05-17-2011 05:09 AM  7 years agoPost 2
lolramen

rrNovice

Marietta, Georgia

My Posts: All  Forum  Topic

I have no experience with the Nova at all, but people always seem to be complaining about crazy vibes coming out of them. The 770 also doesn't like high gain at all from my experience, but if it was working fine with the 50 on there then it shouldn't be an issue.

PM  EMAIL  GALLERY  Attn:RR  Quote
05-17-2011 11:42 PM  7 years agoPost 3
barely can fly

rrApprentice

oxford ga. usa

My Posts: All  Forum  Topic

We have three nova 57's here and all 3 cause some kind of tail nervousness, most noticeable is what appears to be a tail wag when in a hover in time with the pulse of the engine, same thing as you are describing.
Most single cylinder engines of any kind can have a sort of power pulse when running at certian rpm's, especially high performance engines, usually when under partial loads, this engine appears to have a very noticeable one.
You will also see a tail wag in a hover if the engine is at a certian rpm and trying to go on and off the pipe, this is very noticeable at the rotor rpm that you said it was at.
This engine is going to like a higher headspeed than 2100, makes full power at about 18,500 divided by 8.5 gives you 2176, somewhere around 2180 to 2200 is what we are running here.

PM  EMAIL  Attn:RR  Quote
05-18-2011 12:06 AM  7 years agoPost 4
jasonrusso

rrApprentice

Haverhill, Massachusetts

My Posts: All  Forum  Topic

So, at 2200 head speed, is the wag still there? I don't have any wag at lower headspeeds.

PM  EMAIL  GALLERY  Attn:RR  Quote
05-18-2011 11:23 AM  7 years agoPost 5
barely can fly

rrApprentice

oxford ga. usa

My Posts: All  Forum  Topic

Always seems to be there, but not as much at lower headspeeds, seems to be linked to the way the engine makes its power.
And at higher rpm there will be more vibration, we have tried every possible combo of foam and tape and many different gyros, the only one that didn't seem to be bothered by the vibration was the spartan ds760.
Most here now running v-bar and just learn to put up with the tail twitches while in a hover.

PM  EMAIL  Attn:RR  Quote
05-18-2011 05:13 PM  7 years agoPost 6
barely can fly

rrApprentice

oxford ga. usa

My Posts: All  Forum  Topic

You didn't say which pipe you were using, you have to use the nova pipe or you will never see the full potential of the engine, all other pipes are designed to make power at 15,000 to 16,000.
I tried other pipes to see if i could get rid of the tail problems and immediatly lost power.
The nova pipe is the only one designed to work at 18,000 rpm.

PM  EMAIL  Attn:RR  Quote
05-18-2011 05:34 PM  7 years agoPost 7
jasonrusso

rrApprentice

Haverhill, Massachusetts

My Posts: All  Forum  Topic

Yes, I am using the REX pipe.

PM  EMAIL  GALLERY  Attn:RR  Quote
05-18-2011 07:50 PM  7 years agoPost 8
rilopez825

rrVeteran

Pembroke Pines, FL

My Posts: All  Forum  Topic

I removed my Rossi for an os 55 because of vibration issues, same issue as you. If I would set it past 2000rpms the vbar would go nutty and the log would show extreme vibrations then gyro sensor failure. Sense I put the os 55 I have none of these problems. I can take it to 2200rpm without any vib issues.

Richard

PM  EMAIL  GALLERY  Attn:RR  Quote
05-18-2011 08:44 PM  7 years agoPost 9
barely can fly

rrApprentice

oxford ga. usa

My Posts: All  Forum  Topic

As stated by these other folks and myself vibration is part of the package which is a shame because the nova is a work of art internally and makes the power to back it up, is bullet proof as well, one here running for 2 years, same piston, ring, sleeve and bearings with hundreds of flights and still running like it did when new, one died from total operator error and mine i sold because i did not like the howl it made while flying, still flying here in another heli.
Sounded like an out of control buzzsaw, not exactly but the only way i can describe it.
Tried the OS 55 and had to put bearings in after about 2 gallons this while still very rich running.
Settled on the ys 56 and love it, can do tick tocs and flips continuously at 1900 rpm with out loosing any rpm at all.
One other thing is the nova needs to be very rich at idle, sort of blubbering when you try to rev up, not sloppy rich but will idle but if you idle to long it could die, after first flight when up to temp should idle fine even in a long auto, hope some of this helps.

PM  EMAIL  Attn:RR  Quote
05-19-2011 01:39 AM  7 years agoPost 10
jasonrusso

rrApprentice

Haverhill, Massachusetts

My Posts: All  Forum  Topic

Ok, well this isn't very promising. I was expecting good things with this expensive motor. If I start flying (I haven't tried yet), does the tail shudder? I can deal with it in a hover, but not coming out of a hard turn.

PM  EMAIL  GALLERY  Attn:RR  Quote
05-19-2011 11:19 AM  7 years agoPost 11
barely can fly

rrApprentice

oxford ga. usa

My Posts: All  Forum  Topic

You won't notice it while flying, only in a hover.

PM  EMAIL  Attn:RR  Quote
05-19-2011 12:51 PM  7 years agoPost 12
Dino Spadaccini

rrElite Veteran

USA

My Posts: All  Forum  Topic

has any one thought the add shims to the head as you maybe over compressed for 30%

RIP Roman JR
Capt USA Align Factory Team Align - Conquer Your heart
Team Futaba

PM  EMAIL  GALLERY  Attn:RR  Quote
05-19-2011 01:26 PM  7 years agoPost 13
rilopez825

rrVeteran

Pembroke Pines, FL

My Posts: All  Forum  Topic

I changed the shims and it still had the vib issues.
My motor also developed an uneven rpm. It was all over the place.
I was able to fly it with the tail wag, but as needed more power and rpms that's when my problems started. I tried every needle setting and it didn't matter. Vibes where always there.

Richard

PM  EMAIL  GALLERY  Attn:RR  Quote
05-19-2011 09:20 PM  7 years agoPost 14
barely can fly

rrApprentice

oxford ga. usa

My Posts: All  Forum  Topic

Jason, as said above what number of shims do you have under the head, should be .05 for 30% nitro.
One other thing, what glowplug are you using, (this will probably start a hot debate), but this engine has very radical port timing and if you are using the plug that came with the engine it is a hot plug and depending on weather conditions where you are could have the timing to far advanced causing extra vibration, if this is the plug you are using try going to a os #8, this will retard the timing somewhat and could help smooth things out a little.
When i was using the nova i kept a complete range of plugs from hot/#3 to cold/#10 or a5 as changes in weather conditions had a huge effect on the way this engine ran.

PM  EMAIL  Attn:RR  Quote
05-19-2011 10:32 PM  7 years agoPost 15
Chickenrun

rrVeteran

Lincolnshire England UK

My Posts: All  Forum  Topic

Have been bitten in the past with the Nova Rossi never again ... POS

OS all the way, but not the hyper 90

Cheers

PM  EMAIL  Attn:RR  Quote
05-19-2011 11:02 PM  7 years agoPost 16
barely can fly

rrApprentice

oxford ga. usa

My Posts: All  Forum  Topic

One other thing, take the os carb off and put the nova carb back on, never had any problems tuning a nova carb even the two needle works fine.
Not all carbs are created equal, take two carbs from two different engines, even though the needles may be set the same number of turns the tapers on the needles and the holes they are passing fuel through are not always the same.
After this i am out of ideas, hope some off this solves your problem.
If nothing else just enjoy the flight.

PM  EMAIL  Attn:RR  Quote
05-20-2011 01:52 AM  7 years agoPost 17
jasonrusso

rrApprentice

Haverhill, Massachusetts

My Posts: All  Forum  Topic

Shims: I'm not sure. I bought this engine used, and I never checked. The person I bought this from said he ran 30% with no problems. I AM running Curtis Youngblood 30%. I am using an OS #8 plug.

I was planning on reinstalling the Rossi carb. I don't think this is my issue, but it is worth a try.

The weather around here has sucked recently, so not much flying. It is fustrating when I try some things, then go to the field I have a problem. I then have to wait until the next week (or more) before I can try anything again. I guess that is why I bring 2 helis with me.

PM  EMAIL  GALLERY  Attn:RR  Quote
05-29-2011 03:41 PM  7 years agoPost 18
jasonrusso

rrApprentice

Haverhill, Massachusetts

My Posts: All  Forum  Topic

So thanks to everybody. I turned the headspeed up to 2200 and the skake is minimized. Still there a little, but not like it was at 2100. I also turned the engine speed down in normal mode so it will lift off at a slower head speed. I only use normal for takeoff and landing.

PM  EMAIL  GALLERY  Attn:RR  Quote
06-20-2011 04:18 AM  7 years agoPost 19
jasonrusso

rrApprentice

Haverhill, Massachusetts

My Posts: All  Forum  Topic

So, i've been flying the Novarossi for about 3 weeks. It runs great. I love the power, but the tail twitch still bothers me a little. It twitches at idle, but it was also twitching a little when coming out of a hard turn (it was windy today). I am using a regular gyro mounting pad. Should I try a different gyro mounting strategy? This thing really vibrates bad! It moves around on the bench when it is idling. If this is normal, then it is normal. I'll deal with it.

PM  EMAIL  GALLERY  Attn:RR  Quote
06-20-2011 01:14 PM  7 years agoPost 20
Dino Spadaccini

rrElite Veteran

USA

My Posts: All  Forum  Topic

a better place for this post or your question would be in the motor section

RIP Roman JR
Capt USA Align Factory Team Align - Conquer Your heart
Team Futaba

PM  EMAIL  GALLERY  Attn:RR  Quote
WATCH
 2 pages [ <<    <    ( 1 )     2     NEXT    >> ] 1877 views POST REPLY
HomeAircraftHelicopterAlignT-REX 600N › Tail shudder with Novarossi .57
 Print TOPIC  Make Suggestion 

 4  Topic Subscribe

Sunday, December 16 - 10:44 am - Copyright © 2000-2018 RunRyder   EMAILEnable Cookies

The RC discussion world needs to consolidate. RR is now one choice for that. Its software is cutting edge. It hosts on-topic advertising. Help RR increase traffic buy making suggestions, posting in RR's new areas (sites) and by spreading the word.

The RunRyder Difference

• Category system to allow Rep/Vendor postings.
• Classifieds with sold (hidden) category.
• Classifieds with separate view new.
• Answer PMs offsite via email reply.
• Member gallery photos with advanced scripting.
• Gallery photo viewer integrated into postings.
• Highly refined search with advanced back end.
• Hosts its own high end fast response servers.
• Hosts thousands of HD event coverage videos.
• Rewrote entire code base with latest technology.
• No off-topic (annoying) click bait advertising.
Login Here
 New Subscriptions 
 Buddies Online