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franknsled · 04-08-2014, 04:27 PM

I have some tail bounce when I first spool up (as soon as blades are turning). It goes away as soon as I raise the throttle. Is this normal or is it a sign of a tail problem or something else? I know there is serious slop in the mainshaft at the top jesus bolt. I tried new bearings in flybar pivot and aluminum flybar. The main shaft is smooth without the head. Very minor vibes. Will a lynx main shaft fit the bolt tighter ?

kevinizer · 04-08-2014, 05:35 PM

Mine does the exact same but flys great nothing to worry about in my apinion but I am no expert

franknsled · 04-08-2014, 06:53 PM

Thanks Kevin. Just waiting for the wind to quit for a test flight. I'm not good enough to fly in any wind!

kevinizer · 04-08-2014, 07:47 PM

Ya still waiting for snow to melt here winter here was to loung and cold lol!

Gladius · 04-09-2014, 08:05 AM

The tail bounce you are experiencing is probably due to your main blades getting slung off axis as the head accelerates. It's not a big deal unless it causes the heli to tip over. You can tighten the blades just a little bit more snug to reduce the bounce a little.

When you say slop at the Jesus bolt, you mean that the main shaft can rotate just a little bit around the Jesus bolt/head? I would not live with that, and would replace the main shaft and/or the head, depending on which was causing the problem. If that looseness wears/fatigues the Jesus bolt, your whole head could go rocketing off the heli.

franknsled · 04-09-2014, 03:29 PM

Yes. The head can move without moving the main shaft. Will a new shaft be better or should /can I upgrade to something else? I've noticed this "slop" since I got the heli. It was a "brand new never flown" Ebay special. Came in a RTF box but was sold as BNF.

Gladius · 04-09-2014, 06:09 PM

The BNF and RTF 450's come in the same box from HH. Your head should have two slots in it. This allows the head to grip the main shaft when you tighten down the Jesus bolt. Try that to see if you can eliminate the play. If you can't, then you will need a new head and/or shaft. I'd try a shaft first, since you'll most likely need another main shaft at some point anyway. Then try a new head.

franknsled · 04-09-2014, 10:30 PM

Have another shaft. It seems as loose as the first. How much of the jesus bolt sticks out of the nut? I don't want to over tighten it(I'm very good at that!

)

Gladius · 04-10-2014, 07:11 AM

It's hard to say how much to tighten, as I have developed a feel for how much is enough. I would tell you to just do a little bit at a time, then check for tightness of the head. If still loose, tighten a little more. If you tighten too much, and the Jesus bolt breaks, then pull out the pieces, and get a new one with a new head.

If you have a LHS nearby, you can bring it to them, and let someone with a feel for it try to tighten up your head.

04-08-2014, 04:27 PM	#1 (permalink)
franknsled Registered Users Join Date: Jul 2013 Location: Alberta, Canada	Another tail bounce ? I have some tail bounce when I first spool up (as soon as blades are turning). It goes away as soon as I raise the throttle. Is this normal or is it a sign of a tail problem or something else? I know there is serious slop in the mainshaft at the top jesus bolt. I tried new bearings in flybar pivot and aluminum flybar. The main shaft is smooth without the head. Very minor vibes. Will a lynx main shaft fit the bolt tighter ?

04-09-2014, 08:05 AM	#5 (permalink)
Gladius Registered Users Join Date: Nov 2012 Location: Maryland	The tail bounce you are experiencing is probably due to your main blades getting slung off axis as the head accelerates. It's not a big deal unless it causes the heli to tip over. You can tighten the blades just a little bit more snug to reduce the bounce a little. When you say slop at the Jesus bolt, you mean that the main shaft can rotate just a little bit around the Jesus bolt/head? I would not live with that, and would replace the main shaft and/or the head, depending on which was causing the problem. If that looseness wears/fatigues the Jesus bolt, your whole head could go rocketing off the heli. __________________ <> Trex 600 ESP FBL, Trex 500 ESP FBL, Gaui X3, Oxy 3 <> <> Builds in progress: Logo 600SX, Synergy 516 <> *Spartan Vortex VX1e*

04-09-2014, 06:09 PM	#7 (permalink)
Gladius Registered Users Join Date: Nov 2012 Location: Maryland	The BNF and RTF 450's come in the same box from HH. Your head should have two slots in it. This allows the head to grip the main shaft when you tighten down the Jesus bolt. Try that to see if you can eliminate the play. If you can't, then you will need a new head and/or shaft. I'd try a shaft first, since you'll most likely need another main shaft at some point anyway. Then try a new head. __________________ <> Trex 600 ESP FBL, Trex 500 ESP FBL, Gaui X3, Oxy 3 <> <> Builds in progress: Logo 600SX, Synergy 516 <> *Spartan Vortex VX1e*

04-10-2014, 07:11 AM	#9 (permalink)
Gladius Registered Users Join Date: Nov 2012 Location: Maryland	It's hard to say how much to tighten, as I have developed a feel for how much is enough. I would tell you to just do a little bit at a time, then check for tightness of the head. If still loose, tighten a little more. If you tighten too much, and the Jesus bolt breaks, then pull out the pieces, and get a new one with a new head. If you have a LHS nearby, you can bring it to them, and let someone with a feel for it try to tighten up your head. __________________ <> Trex 600 ESP FBL, Trex 500 ESP FBL, Gaui X3, Oxy 3 <> <> Builds in progress: Logo 600SX, Synergy 516 <> *Spartan Vortex VX1e*

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04-08-2014, 05:35 PM	#2 (permalink)
kevinizer Registered Users Join Date: Jan 2009	Mine does the exact same but flys great nothing to worry about in my apinion but I am no expert

04-08-2014, 06:53 PM	#3 (permalink)
franknsled Registered Users Thread Starter Join Date: Jul 2013 Location: Alberta, Canada	Thanks Kevin. Just waiting for the wind to quit for a test flight. I'm not good enough to fly in any wind!

04-08-2014, 07:47 PM	#4 (permalink)
kevinizer Registered Users Join Date: Jan 2009	Ya still waiting for snow to melt here winter here was to loung and cold lol!

04-09-2014, 03:29 PM	#6 (permalink)
franknsled Registered Users Thread Starter Join Date: Jul 2013 Location: Alberta, Canada	Yes. The head can move without moving the main shaft. Will a new shaft be better or should /can I upgrade to something else? I've noticed this "slop" since I got the heli. It was a "brand new never flown" Ebay special. Came in a RTF box but was sold as BNF.

04-09-2014, 10:30 PM	#8 (permalink)
franknsled Registered Users Thread Starter Join Date: Jul 2013 Location: Alberta, Canada	Have another shaft. It seems as loose as the first. How much of the jesus bolt sticks out of the nut? I don't want to over tighten it(I'm very good at that! )

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