Tail blows out on hard punchouts

fuzzyllamma · 05-14-2012, 08:24 AM

I was doing some inverted punchouts today and at dropping the stick hard, the tail would completely pirouette out of control for a few seconds (first piro flip!

). I suspect that my problem is either bad tail bearings or my futaba 9257. I already replaced my tail bearings with the boca replacements and i have the futaba gears on order (some of you may remember my earlier thread on a "clicking" noise). As far as i know, the tail is not binding in any other spot. Is there anything else that could be causing my issue? I am using the ar7200bx and it has been working flawlessly except for recently in ff flight, the head will bob and tail will wag. I know that decreasing cyclic gain and tail dynamic will probably fix this, but it has been doing fine up until the tail blowouts. Would the bad tail cause the head bob?

dl5973 · 05-14-2012, 07:02 PM

have you tried the inverted punshout before?

does this happen with upright hard stick punchouts?

'

fuzzyllamma · 05-14-2012, 08:37 PM

Yeah i have done them before. Its only recently that it has started acting up. I cant get it to do it in upright orientation. Am i using too much pitch and stalling the head maybe?

fuzzyllamma · 05-14-2012, 08:38 PM

15 degrees of negative*

Wolfpackin · 05-14-2012, 10:42 PM

Quote:

Originally Posted by fuzzyllamma

15 degrees of negative*

Quote:

Originally Posted by fuzzyllamma

Am i using too much pitch and stalling the head maybe?

Could be, depending on collective management and headpeed.

I'd start by trying lower collective pitch and high headspeeds, see if that helps.
Also look for anything slipping in the tail system when torqued.

Starcruiser · 05-15-2012, 09:21 AM

reset the collective range to make it symmetrical, i.e. + 13° and - 13° (or whatever range you prefer). the -15° is too much IMO thus causing the blow out. You could also check your governor (if you are using one) or if not then change up the throttle curve to a mild "V" to increase head-speed to avoid the bogging.

fuzzyllamma · 05-15-2012, 10:39 AM

Im already running 3500 hs governed with my scorp -6. I do have it symmetrical at +-15. Ill change it up and see if i can replicate it. Thanks for the input guys.

Starcruiser · 05-15-2012, 02:09 PM

I run a Scorpion -6 on one of my 450's too and it likes to blow out for a 360 or so on hard collective input. I am playing with the governor (CC ICE 50) to see how I can minimize it. I run at +/-13° so on a hard punch out it will lose it, tweaking the governor gain has reduced it but the -6 is a torque monster. I also reduced the head speed to about 3k (I was running it at like 3400 prior).

I am running a 13T pinion, 2200mAh Hyperions 35c with a Vbar Mini Blue and a ICE 50 w/heatsink in fixed RPM mode.

fuzzyllamma · 05-27-2012, 01:31 PM

I changed a couple things - flipped the grips and also turned on the tail precomp on the beastx. Seems to have remedied the issue it twitches a little bit if i punch it really hard but it is nothing that i am really worried about. Thanks for the suggestions.

05-14-2012, 08:24 AM	#1
fuzzyllamma Registered Users Join Date: Dec 2011 Location: canada	Tail blows out on hard punchouts I was doing some inverted punchouts today and at dropping the stick hard, the tail would completely pirouette out of control for a few seconds (first piro flip! ). I suspect that my problem is either bad tail bearings or my futaba 9257. I already replaced my tail bearings with the boca replacements and i have the futaba gears on order (some of you may remember my earlier thread on a "clicking" noise). As far as i know, the tail is not binding in any other spot. Is there anything else that could be causing my issue? I am using the ar7200bx and it has been working flawlessly except for recently in ff flight, the head will bob and tail will wag. I know that decreasing cyclic gain and tail dynamic will probably fix this, but it has been doing fine up until the tail blowouts. Would the bad tail cause the head bob?

05-15-2012, 09:21 AM	#6
Starcruiser Registered Users My HF Map location Join Date: Sep 2009 Location: Rockford, Illinois	reset the collective range to make it symmetrical, i.e. + 13° and - 13° (or whatever range you prefer). the -15° is too much IMO thus causing the blow out. You could also check your governor (if you are using one) or if not then change up the throttle curve to a mild "V" to increase head-speed to avoid the bogging. __________________ Carl Trex 550E FS Vbar Pro 5.2- EXI-450T Mini Vbar Pro 5.2 - EXI 450T BeastX - Trex 250SE - mCPx v1 Hp05 & HP06 w/HP03t tails - AMA #952544

05-15-2012, 02:09 PM	#8
Starcruiser Registered Users My HF Map location Join Date: Sep 2009 Location: Rockford, Illinois	I run a Scorpion -6 on one of my 450's too and it likes to blow out for a 360 or so on hard collective input. I am playing with the governor (CC ICE 50) to see how I can minimize it. I run at +/-13° so on a hard punch out it will lose it, tweaking the governor gain has reduced it but the -6 is a torque monster. I also reduced the head speed to about 3k (I was running it at like 3400 prior). I am running a 13T pinion, 2200mAh Hyperions 35c with a Vbar Mini Blue and a ICE 50 w/heatsink in fixed RPM mode. __________________ Carl Trex 550E FS Vbar Pro 5.2- EXI-450T Mini Vbar Pro 5.2 - EXI 450T BeastX - Trex 250SE - mCPx v1 Hp05 & HP06 w/HP03t tails - AMA #952544

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05-14-2012, 07:02 PM	#2
dl5973 Registered Users Join Date: Feb 2007 Location: Sydney Australia	have you tried the inverted punshout before? does this happen with upright hard stick punchouts? '

05-14-2012, 08:37 PM	#3
fuzzyllamma Registered Users Thread Starter Join Date: Dec 2011 Location: canada	Yeah i have done them before. Its only recently that it has started acting up. I cant get it to do it in upright orientation. Am i using too much pitch and stalling the head maybe?

05-14-2012, 08:38 PM	#4
fuzzyllamma Registered Users Thread Starter Join Date: Dec 2011 Location: canada	15 degrees of negative*

05-15-2012, 10:39 AM	#7
fuzzyllamma Registered Users Thread Starter Join Date: Dec 2011 Location: canada	Im already running 3500 hs governed with my scorp -6. I do have it symmetrical at +-15. Ill change it up and see if i can replicate it. Thanks for the input guys.

05-27-2012, 01:31 PM	#9
fuzzyllamma Registered Users Thread Starter Join Date: Dec 2011 Location: canada	I changed a couple things - flipped the grips and also turned on the tail precomp on the beastx. Seems to have remedied the issue it twitches a little bit if i punch it really hard but it is nothing that i am really worried about. Thanks for the suggestions.