Overspeed problem?

[TomCarey]

Clutch stack bearings were changed not to long ago, still have the problem after re mounting... Sending the b/x to horizon just to make
sure there is no fault with it.

[Planehazza]

Its not doing an uncommanded role just flying around its only when head is put under load then off load i get the uncontrolable 1-2 sec wobble / drop which will end up
in curtains

Is it a wobble, or a shudder on all axis, like a waggy tail? If I had my beastX gain too high, it would wobble and shudder like crazy in FFF. This too, would feel like I lost control for a couple of seconds until the model slowed enough to return full control. Try lowering your gain 5% and try it again mate. I always found the beastx liked a hard pad so I'd be reluctant to add more foam.

[TomCarey]

It's a wobble off to the left, it's tips over

[Planehazza]

It's a wobble off to the left, it's tips over

I had this problem spooling up on the ground with an ElyQ 90. The clutch stack design was poor and was very difficult to get perfectly straight. It would try to tip over aggressively on spool up.

[scallybert]

Measure the Vibes..!

A lot of people have said this is likely to be a vibration issue [which is what it sounded like to me on Sunday, when Steve mentioned it - and I think he thinks so too..? ]

I know this isn't 'the way', but surely it would be better to measure the vibrations, rather than tinker around, replacing a lot of parts, to hopefully hit upon whatever the problem happened to be ?

It used to be that only Skookum SK-720s had vibration analysis facilities; but I believe that these days more mainstream FBLs have them too. [Can someone shed a light here ? V-Bars ? Vortex ? Affordable ?]

If a suitable FBL is available [I might have a spare V-Bar, if they do it - it's on a certain 380], strap one of those on, and measure the vibes. [I've even strapped on a second FBL, just to measure the vibes..!] The frequency and axis will usually tell you what the culprit is, and then you can figure out how to fix it.

BTW, the SK anti-vibe kit included a heavy plate under the FBL, with thick foam between that and the heli, to provide decoupling. ie not just thinner or thicker foam.

[brin]

great Idea. would be great if they had some sort of a sonar gun you could point at it to show where the vibes where coming from or is that to far fetched lol

A lot of people have said this is likely to be a vibration issue [which is what it sounded like to me on Sunday, when Steve mentioned it - and I think he thinks so too..? ]

I know this isn't 'the way', but surely it would be better to measure the vibrations, rather than tinker around, replacing a lot of parts, to hopefully hit upon whatever the problem happened to be ?

It used to be that only Skookum SK-720s had vibration analysis facilities; but I believe that these days more mainstream FBLs have them too. [Can someone shed a light here ? V-Bars ? Vortex ? Affordable ?]

If a suitable FBL is available [I might have a spare V-Bar, if they do it - it's on a certain 380], strap one of those on, and measure the vibes. [I've even strapped on a second FBL, just to measure the vibes..!] The frequency and axis will usually tell you what the culprit is, and then you can figure out how to fix it.

BTW, the SK anti-vibe kit included a heavy plate under the FBL, with thick foam between that and the heli, to provide decoupling. ie not just thinner or thicker foam.

[TomCarey]

Having the b/x checked first by horizon then will go from there, another opinion mentioned a potential servo on the way out as its dropping to the left..

[scallybert]

great Idea. would be great if they had some sort of a sonar gun you could point at it to show where the vibes where coming from or is that to far fetched lol

I suspect that temporarily strapping on one of the FBLs that support vibe analysis would be cheaper and easier. [IME, it doesn't even need to be the one controlling the heli..! I strapped an SK-720 over a battery pack, and bound an extra sat for it. Only in the kithen, though.]

Bear in mind Tom's experience is typical - ie it only happens under specific circumstances. This means you have to log during a flight when you provoke the behaviour. You won't see it on the ground

BTW, one of the posts about vibes and Beast-X referred to a roll caused by an out of balance tail - probably at specific RPM.

[mattscupoftea]

I suspect that temporarily strapping on one of the FBLs that support vibe analysis would be cheaper and easier. [IME, it doesn't even need to be the one controlling the heli..! I strapped an SK-720 over a battery pack, and bound an extra sat for it. Only in the kithen, though.]

Bear in mind Tom's experience is typical - ie it only happens under specific circumstances. This means you have to log during a flight when you provoke the behaviour. You won't see it on the ground

BTW, one of the posts about vibes and Beast-X referred to a roll caused by an out of balance tail - probably at specific RPM.

I concur with the vibe argument.

It was pointed out to me that BeastX rolls right when there is a vibe issue. I mentioned that this may be true, but in most cases, beastX are mounted at the read of the heli with wires backwards, whereas this one is at the front with wires forward, which to me suggests that the 'BeastX vibe reaction' would happen in reverse. Does this make sense?

I wanted to suggest using one of my Vbars on the heli, with a bluetooth adapter (which I have) attached, and checking the vibes on the heli via phone or laptop. I was hesitant though, cos I didn't want to rip the mini Vbar off one of my working helis (and also didn't have the heli to hand on the day). I believe you can get a good idea of where any excessive vibes are coming from by the frequency of the vibrations. By the sounds of it though, and based on other peoples experience (which so often points to the real problem) there may be a problem with the clutch stack bearings.

When I flew the heli on Sunday, it rolled left for me on FF on the way out of a stall turn. Horrible feeling. Landed immediately! The fact that the problem occurs on release of head loading in different situations does suggest that it happens on a change of headspeed, which in turn suggests resonance at a certain rpm causing the issue.

Perhaps when the BeastX arrives back from its health check we can continue the investigation. . ?

[TomCarey]

I concur with the vibe argument.

It was pointed out to me that BeastX rolls right when there is a vibe issue. I mentioned that this may be true, but in most cases, beastX are mounted at the read of the heli with wires backwards, whereas this one is at the front with wires forward, which to me suggests that the 'BeastX vibe reaction' would happen in reverse. Does this make sense?

I wanted to suggest using one of my Vbars on the heli, with a bluetooth adapter (which I have) attached, and checking the vibes on the heli via phone or laptop. I was hesitant though, cos I didn't want to rip the mini Vbar off one of my working helis (and also didn't have the heli to hand on the day). I believe you can get a good idea of where any excessive vibes are coming from by the frequency of the vibrations. By the sounds of it though, and based on other peoples experience (which so often points to the real problem) there may be a problem with the clutch stack bearings.

When I flew the heli on Sunday, it rolled left for me on FF on the way out of a stall turn. Horrible feeling. Landed immediately! The fact that the problem occurs on release of head loading in different situations does suggest that it happens on a change of headspeed, which in turn suggests resonance at a certain rpm causing the issue.

Perhaps when the BeastX arrives back from its health check we can continue the investigation. . ?

The exact same thing happened to me coming out of a stall turn complete through me off and scared the bee Jesus out of me!

[scallybert]

I concur with the vibe argument.

[...]
I wanted to suggest using one of my Vbars on the heli, with a bluetooth adapter (which I have) attached, and checking the vibes on the heli via phone or laptop. I was hesitant though, cos I didn't want to rip the mini Vbar off one of my working helis (and also didn't have the heli to hand on the day). I believe you can get a good idea of where any excessive vibes are coming from by the frequency of the vibrations. By the sounds of it though, and based on other peoples experience (which so often points to the real problem) there may be a problem with the clutch stack bearings.

If a mini Vbar will do the job, and you know how to do it, I'm pretty sure I've got one to hand [Either pull off this G380 in the office, or one I had on a T-Rex450]. Let me know if it's required. NB, with the Spartans, it seems the 'mini versions' don't do vibe analysis - so maybe check first.

Aside from the frequency, the other clue is what axes the vibes are happening in.

[scallybert]

Spartan VX1 will do it..: Vortex System Menu : Vibr. Analysis - HeliFreak

One for sale here..: http://www.rcheliaddict.co.uk/sale/1...full-size.html