RunRyder RC
WATCH
 2 pages [ <<    <     1     ( 2 )    >    >> ] 2012 views POST REPLY
HomeAircraftHelicopterHIROBOHirobo SDX › Help tracking down a tail vibe after a rough auto
04-29-2010 01:23 AM  8 years agoPost 21
Aaron29

rrProfessor

USA

My Posts: All  Forum  Topic

Believe me I have learned this the hard way.
Same here which is why just to rule it out I'd check it.

I replaced my engine's bearing, I tried changing fuel, shimming, mainshaft, tailshaft, blah blah blah.

Someone suggested a new clutch, so I bought one, installed it.

Smooth as glass.

And it's such an easy/quick thing to do, at least rule it out.

PM  EMAIL  GALLERY  Attn:RR  Quote
04-30-2010 02:12 PM  8 years agoPost 22
Against Gravity

rrVeteran

Pottstown PA

My Posts: All  Forum  Topic

Any Luck ?
Tron
Don't leave us hang here with the shakes. It helps everyone to find out the fix.

AG

PM  EMAIL  GALLERY  Attn:RR  Quote
05-01-2010 12:55 AM  8 years agoPost 23
JeremyF

rrNovice

Australia

My Posts: All  Forum  Topic

check to see if your feathering shaft is centered properly! this is a bit of adjustment (side play) there. My vibe was due to this, how i assembled it is too center the round collet that goes onto the middle of the feathering shaft then tighten the little set screw, not by putting the whole assembly with main grips on then tighten the set screw.

cheers

Jeremy

PM  EMAIL  GALLERY  Attn:RR  Quote
05-01-2010 07:23 AM  8 years agoPost 24
Tron

rrApprentice

Morgan Hill, CA

My Posts: All  Forum  Topic

I'm working for the man during the week so no heli play time.

The spindle centering suggestion is interesting although I'm not so sure it is super critical to be exactly centered. The flat spot on the spindle does allow for some variation from build to build. I just eyeballed it on initial assembly and it seemed to be fine.

Weekend plan:
I'm going to remove the high speed needle and pump some fuel into the inlet nipple to flush it out. Put back needle and see if the engine starts any better (eg without having to advance the throttle so much). If no improvement, I'm going to drop the engine, check the clutch/starter shaft assembly, remove the crankshaft and have a good look at that rear bearing.

Then on Monday, I go back to working for the man and put my order in for one or more of these:
rear bearing
new engine
starter shaft

PM  EMAIL  GALLERY  Attn:RR  Quote
05-01-2010 10:55 AM  8 years agoPost 25
JeremyF

rrNovice

Australia

My Posts: All  Forum  Topic

just give the feathing shaft idea a go! least that way u tried something else!

cheers

Jeremy

PM  EMAIL  GALLERY  Attn:RR  Quote
05-18-2010 06:52 AM  8 years agoPost 26
Tron

rrApprentice

Morgan Hill, CA

My Posts: All  Forum  Topic

Crusade update.

Old engine's rear bearing was fine. The piston ring had broken a piece off. Needed a new piston and ring for sure but the head looked beat up from injesting ring pieces so I just got a new engine.

Been waiting on a new engine and finally got it installed and hovered around for engine break in on Sunday. Half a tank spent cycling between hovering and idleing before my WTF? moment hit.

Spooling up from an idle and see that I have no tail control. I was just hovering the heli a minute ago so I don't know what could have happened. Never shut it down, was on my first tank and still had all controls except rudder. I kill the engine and move the rudder stick and the tail doesn't move at all! I bring it back to the bench (rx and tx still powered on ) and pull the canopy to see if a plug has loosened or something. I then notice that the AR7000 satellite receiver led is flashing! The main receiver led is solid though. Now I'm really puzzled. First flight off a just charged 2S lipo running through arizona regulator. How the heck do I get a brown out condition?

So now I have a non functioning BLS 251 (running spartan 760) that I get to play with this weekend. Maybe the tail servo was on its way out causing my vibe and that it just died when it did? How should I test if the servo is really dead or just playing possum?

The heli gods are punishing me for not flying my heli more often.

PM  EMAIL  GALLERY  Attn:RR  Quote
05-18-2010 11:40 AM  8 years agoPost 27
Against Gravity

rrVeteran

Pottstown PA

My Posts: All  Forum  Topic

Did you reset
Try powering off like normal and start up fresh. If it still does not work re setup your Gyro.
Maybe you bumped your power switch, or there is a bad connection. Bench it and start shaking all connections.

AG

PM  EMAIL  GALLERY  Attn:RR  Quote
05-18-2010 03:32 PM  8 years agoPost 28
JuanRodriguez

rrProfessor

The Villages, Florida

My Posts: All  Forum  Topic

How should I test if the servo is really dead or just playing possum?
Plug the "suspect" servo directly into one of the slots in your transmitter to see if it works.....

It's just a process of elimination but only do ONE thing at a time to find the problem....

Been there, done that and old enough to know better.....

PM  EMAIL  GALLERY  Attn:RR  Quote
05-18-2010 04:09 PM  8 years agoPost 29
Paul Woodcock

rrElite Veteran

Dubai - United Arab Emirates

My Posts: All  Forum  Topic

Hi Guys

Don't plug the BLS251 directly into the Rx......

Regarding the brown out. Are you 100% sure you didn't cycle the Rx power and create a false brown out blinking????

Regards
Paul

PS: Gyro servos don't give you much warning of a failure. If you are worried, move the servo left and right for about 5 min, with your thumb lightly pressing on the servo horn. This will simulate a 'flight load'.

PM  EMAIL  GALLERY  Attn:RR  Quote
05-18-2010 07:00 PM  8 years agoPost 30
JuanRodriguez

rrProfessor

The Villages, Florida

My Posts: All  Forum  Topic

Don't plug the BLS251 directly into the Rx......
Can you explain why ? He's running a "regulated" system so I don't believe voltage should be an issue ??

Been there, done that and old enough to know better.....

PM  EMAIL  GALLERY  Attn:RR  Quote
05-19-2010 05:02 AM  8 years agoPost 31
Paul Woodcock

rrElite Veteran

Dubai - United Arab Emirates

My Posts: All  Forum  Topic

Hi guys

The Futaba 9251,9256 and BLS251 require the narrow pulse (760µs) input from the gyro.

You will break the servo if you plug it directly into the Rx.

Regards
Paul

PM  EMAIL  GALLERY  Attn:RR  Quote
05-19-2010 08:07 AM  8 years agoPost 32
Tron

rrApprentice

Morgan Hill, CA

My Posts: All  Forum  Topic

absolutely positive I did not cycle the rx. running the arizona so it's always on unless I disconnect the lipo or plug in the pin.

tonight I tried rebinding the rx, reloading the gyro setting via the spartan usb and laptop (saved from my last good setup), checking lipo voltage (8.04V), and checking arizona's output voltage to gyro (4.98V). Tail servo still don't move. All other channels operating fine. Even gyro goes in and out of heading hold mode with the usual switch.

plugged in a regular servo directly to the rudder channel to check if maybe the tx rudder stick is bad. No problem moving that analog servo with left and right rudder stick movement.

Next, rehooked up gyro and bls 251 and powered on as usual. Still no movement of tail servo with rudder. I put gyro into rate mode and use one of the recommendations to put a load on it with my fingers and then move the rudder stick. The servo moves!!!

If I hold full right rudder stick, and apply pressure to the servo horn towards the right servo throw direction, the bls moves full right. It holds that position solid as I tried applying left direction force and could feel the servo buzzing and holding the right position. To move it left, I have to move the rudder stick left and apply left force on the horn. Without my fingers pushing it along in either direction, the servo won't move on it's own.

I set the spartan gyro for the bls 251 so it's got the right 760 micro second pulse. I think the servo has bad spots on 'the pot'.

I'm amazed that the servo would fail so suddenly. One minute I'm hovering with the tail holding fine, land to idle the engine and then the servo dies as I'm spooling up.

Now the servo needs to go in for a check up.

PM  EMAIL  GALLERY  Attn:RR  Quote
05-19-2010 12:03 PM  8 years agoPost 33
Paul Woodcock

rrElite Veteran

Dubai - United Arab Emirates

My Posts: All  Forum  Topic

Hi

Like i said before, gyro servos don't give much warning before failing. You should count yourself lucky it didn't end in a crash.

I would replace it and send the 'failed' one in for a repair. The BLS251 is a great servo and probably worth repairing if it is only the pot.

Having a spare when it gets back is one of those nice to haves....

Regards
Paul

PM  EMAIL  GALLERY  Attn:RR  Quote
06-29-2010 05:55 AM  8 years agoPost 34
Tron

rrApprentice

Morgan Hill, CA

My Posts: All  Forum  Topic

Hiya fellas,

Been a while since I last got out but I have success to report on the vibration front. Turns out it was the main blades! Close the book on this cold case!

It came to me during my hiatus. The set of blades I was using was actually a set of Radix cobbled together from previous crash survivor blades. Mismatched but had been used with no issues on my R50. Seems the SDX is less tolerant of this maybe due to the stiffer dampening.

My first flight was to dial in the new tail servo (put my old trusty 9253 back in) and the vibration was still there. After landing, I put on a new matched set of maverick G5 wide chords. The next flight the vibes were gone! Smooth as silk, tail fin rock solid, no sloshing fuel, all is well with the SDX!

Weird thing is that the main disk was always in track with that mismatched set. When you've checked the obvious spinning shafts, don't overlook the biggest spinning mass on the heli.

Another lesson learned in this fine hobby.

PM  EMAIL  GALLERY  Attn:RR  Quote
WATCH
 2 pages [ <<    <     1     ( 2 )    >    >> ] 2012 views POST REPLY
HomeAircraftHelicopterHIROBOHirobo SDX › Help tracking down a tail vibe after a rough auto
 Print TOPIC  Make Suggestion 

 11  Topic Subscribe

Tuesday, August 21 - 5:07 am - Copyright © 2000-2018 RunRyder   EMAILEnable Cookies

Login Here
 New Subscriptions 
 Buddies Online