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owde · 01-16-2010, 05:59 AM

I've had tail vibes recently too, first greasing the spindle fixed it then having to pull on a blade every now and then. It got so bad I shimmed the spindle then after a while I was pulling on the blades to get rid of it again with the shims in. I have now taken the shims off and ground the spindle both sides about .3 mm this has had the best effect but I can still notice the vibration sound at high HS when the heli is flying, coming down slowly, its like the blades go out of track.

apostolosnt · 01-17-2010, 10:20 AM

When I say "min throttle" I mean just when the main mast starts rotating. And this vibration appeared with the blades off.
Actually I did change the tail shaft to make sure as Jafa suggested and then I corrected a little slack in the flybar. It had a ~0,3mm gap there. Now everything looks good.
I am waiting for some reasonable weather to fly it. I have only tested it in hover today and there is no vibration but I need to fly it and work on the gyro gain.
Thanks for the help guys.

About the spindle I also had to insert a 0,5mm washer in there to take up the slack. There are a couple of things on this heli that you'd expect a more precise job from hirobo... spindle, seesaw and slide block were really bad on mine.

owde · 02-17-2010, 07:15 AM

Well after changing the tail bearings which were getting pretty bad I still had vibes then I changed the lower main bearing because there was a small amount of play with the main mast and amazingly the vibes where gone, very happy. Glad to see you've got your's sorted as well...

husafreak · 04-13-2011, 01:05 PM

Great info guys, thanks, i rebuilt my lepton after a crash and have tail vibe problems, new tail blades, new tail everything, still vibes which increase in intensity with higher headspeeds, you ca hear it in flight... I'm going to look at slop in the grips and flybar cage now.

Jafa · 04-13-2011, 04:38 PM

Did you check the new tail hub?
They are very soft and can be bent from new (just from being dropped)
Put one end of the tail hub into the dremel and spin it up
It will be obvious if it's not straight

The other common cause is the spindle dampers holding the spindle too tight for it to self center

husafreak · 04-13-2011, 08:32 PM

I tried two different tail rotor shafts so I think the head is next.

04-13-2011, 04:38 PM	#25 (permalink)
Jafa Registered Users Join Date: Apr 2005	Did you check the new tail hub? They are very soft and can be bent from new (just from being dropped) Put one end of the tail hub into the dremel and spin it up It will be obvious if it's not straight The other common cause is the spindle dampers holding the spindle too tight for it to self center __________________ Rave 450 \| Lepton \| Logo 400/500/600 \| Aeolus \| Sceadu \| Freya \| Avant FX \| Raptor G4 Gryphon field rep

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01-16-2010, 05:59 AM	#21 (permalink)
owde Registered Users Join Date: Jan 2008	I've had tail vibes recently too, first greasing the spindle fixed it then having to pull on a blade every now and then. It got so bad I shimmed the spindle then after a while I was pulling on the blades to get rid of it again with the shims in. I have now taken the shims off and ground the spindle both sides about .3 mm this has had the best effect but I can still notice the vibration sound at high HS when the heli is flying, coming down slowly, its like the blades go out of track.

01-17-2010, 10:20 AM	#22 (permalink)
apostolosnt Registered Users Join Date: Jan 2008 Location: Cambridge UK	When I say "min throttle" I mean just when the main mast starts rotating. And this vibration appeared with the blades off. Actually I did change the tail shaft to make sure as Jafa suggested and then I corrected a little slack in the flybar. It had a ~0,3mm gap there. Now everything looks good. I am waiting for some reasonable weather to fly it. I have only tested it in hover today and there is no vibration but I need to fly it and work on the gyro gain. Thanks for the help guys. About the spindle I also had to insert a 0,5mm washer in there to take up the slack. There are a couple of things on this heli that you'd expect a more precise job from hirobo... spindle, seesaw and slide block were really bad on mine.

02-17-2010, 07:15 AM	#23 (permalink)
owde Registered Users Join Date: Jan 2008	Well after changing the tail bearings which were getting pretty bad I still had vibes then I changed the lower main bearing because there was a small amount of play with the main mast and amazingly the vibes where gone, very happy. Glad to see you've got your's sorted as well...

04-13-2011, 01:05 PM	#24 (permalink)
husafreak Registered Users Join Date: Dec 2006	Great info guys, thanks, i rebuilt my lepton after a crash and have tail vibe problems, new tail blades, new tail everything, still vibes which increase in intensity with higher headspeeds, you ca hear it in flight... I'm going to look at slop in the grips and flybar cage now.

04-13-2011, 08:32 PM	#26 (permalink)
husafreak Registered Users Join Date: Dec 2006	I tried two different tail rotor shafts so I think the head is next.

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