Tail blowouts

[Delarado]

Guys,

I seem to be getting tail blowouts on my TDR, generally when pushing the tail (E.g large piroing loops) but sometimes randomly at other times (I did a barrell roll the other day and it blew out 90 degrees)

Tail gain is set just below wag at high speeds

710 Rails / 105 Rails
Kontronik 120 Mode 4
Quantum 4530 goblin edition motor + I think 15T pinion?

Anything I can change on Vbar or check? The tail moves smoothly, as does the servo (Its an MKS HBL980 although running at 6V)

Any pointers appreciated!

[TheDan]

Hmmm that does sound suspect. Just as blind guesses I'll throw a few out there... Off the top of my head perhaps stalling tail blades, the servo, or the Vbar?
Easiest first: You could try reducing the travel endpoints for the tail pitch a little to eliminate blade stall as a possibility.
If you have another servo laying around it might be worth a try to swap and see if the MKS has an issue, eliminating the servo.
You might want to check out your logs and vibe analysis on the vbar to see if there is anything unusual. Maybe as simple as new mounting tape or changing gains? If not... there's the painful possibility of the vbar sensor itself... I'm no Vbar expert I'm sure others will have better info regarding settings.
I don't know if that helps or not. You've probably thought of those and more yourself, but good luck getting it sorted out! I hope it's relatively simple.
Cheers.

[TheDan]

Oh, are you using Kontronik gov or Vbar gov? Possibly a governor issue?

[Delarado]

Its the Kontronik gov in mode 4... I'll have a check of the logs, see if I can see anything. Are the TDRs prone to tail blade stall then? Ive not read anything on the subject.

Its easy enough to make it go so I guess I have some testing to do!

[loz]

Would raising the tail precomp help?

[chucky21022010]

Would raising the tail precomp help?

Depends which way the tail is blowing. Right side means too much precomp, so should be decrease and if tail is blowing left side; too less; needs to increase. BTW, default precomp always is too high. As Mr Mels vid on tail tweaking, is set the precomp to 10 on the tail and 2 on the cyclic and start from there.

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[loz]

Depends which way the tail is blowing. Right side means too much precomp, so should be decrease and if tail is blowing left side; too less; needs to increase. BTW, default precomp always is too high. As Mr Mels vid on tail tweaking, is set the precomp to 10 on the tail and 2 on the cyclic and start from there.

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Yeh sorry should have said adjusting the tail precomp

[SaneAdam]

Guys,

I seem to be getting tail blowouts on my TDR, generally when pushing the tail (E.g large piroing loops) but sometimes randomly at other times (I did a barrell roll the other day and it blew out 90 degrees)

Tail gain is set just below wag at high speeds

710 Rails / 105 Rails
Kontronik 120 Mode 4
Quantum 4530 goblin edition motor + I think 15T pinion?

Anything I can change on Vbar or check? The tail moves smoothly, as does the servo (Its an MKS HBL980 although running at 6V)

Any pointers appreciated!

Does it only happen when going extremely fast? We (and others) have noticed that when flying very very fast (not my style, but my mates love speed flying) the Vbar freaks out resulting in the tail letting go and swinging 90 degrees in the same way you describe. I have seen it a few times but only when the heli is obviously pulling extreme g going seriously fast.

A friend of mine noted that some dedicated speed pilots were swapping out their Vbars and replacing with Beastx due to this exact problem. This is only "what i hear" though. But as i say, i have seen it happen…. but only at speeds that i would never consider flying at tbh. Stupidly fast with frame snapping yank and bank turns. F ing scary though when it happens at those speeds

[TheDan]

Its the Kontronik gov in mode 4... I'll have a check of the logs, see if I can see anything. Are the TDRs prone to tail blade stall then? Ive not read anything on the subject.

Its easy enough to make it go so I guess I have some testing to do!

Hey sorry man, I haven't been able to access the website for some reason. I haven't heard of tail blade stall issues being a common problem, it was just an "off the cuff" idea. Honestly, I doubt stall is your problem. Hopefully you get it sorted quickly though! Good luck, keep us updated.