Sceadu Evo 30 tail kick

[Andy Beetz]

Hi,

This is getting really annoying now. During high speed, high bank turns the
tail is kicking out. Just replaced gyro and servo and it's holding really
well, except for this kick. It does it in both directions.



It can kick up to 45 degrees at times. From the ground it looks like a
severe radio glitch. I know it can't be because I can reproduce it every
single time, different directions, different piece of sky etc.


It doesn't do it in slower, shallower turns as often or harshly but you can
see it if you look hard enough. I'm learning to not freak out when it
happens, very difficult to watch the bird sat there convulsing.



I'm running a CSM 420 micro (was using a CSM 360 before but just wouldn't
hold in HH) set to 68% gain. Tail servo is a GWS S19CL aka Supertec S09CL2BB
(0.09s/60deg and 7kg torque). On the recommendation of CSM to maximise the
amount of servo travel, the servo horn is 12.5mm. The tail blades are 85mm
fun-key carbon tech.

The engine is an OS32SXH with weston genesis one piece running factory carb
settings on 15% wildcat and an enya no3 plug. It is running very very
nicely, lots of smoke, but not running rich. It sounds very nice and smooth,
no raspiness to the note at all.

Head is running about 1600 rpm, I've got no wag in the hover, FF or even
FFF. It's just the turns



Any ideas? Any more information required to make a judgement?

TIA

Andy

[Mark Stevens]

"Andy Beetz" <the_flc@REMOVETHISzen.co.uk> wrote in message
news:423d44d9$0$32611$db0fefd9@news.zen.co.uk...
> Hi,
>
> This is getting really annoying now. During high speed, high bank turns
> the tail is kicking out. Just replaced gyro and servo and it's holding
> really well, except for this kick. It does it in both directions.
>
>
>
> It can kick up to 45 degrees at times. From the ground it looks like a
> severe radio glitch. I know it can't be because I can reproduce it every
> single time, different directions, different piece of sky etc.
>
>
> It doesn't do it in slower, shallower turns as often or harshly but you
> can see it if you look hard enough. I'm learning to not freak out when it
> happens, very difficult to watch the bird sat there convulsing.

The fact that it doesn't do it in shallower or slow turns would tend to
suggest to me to back off the sensitivity a bit as it is treating your
harder turns like a sudden weathercock movement and it is trying to
compensate for them...or in this case overcompensate...back off the
sensitivity and try a few flights with it then...see how you get on.

I don't fly with a gyro myself but I do know exactly how they work. (I
learned to fly heli's long before gyro's were on the market and I currently
have 3 Heli's)


--
Regards........Mark
(BlueWaveStudios)
www.scale-models.co.uk (Moderator)

[Andy Beetz]

"Mark Stevens" <spamspamspam@spam.com> wrote in message
news:d1t0rg$gmk$1@newsg1.svr.pol.co.uk...
>
> "Andy Beetz" <the_flc@REMOVETHISzen.co.uk> wrote in message
> news:423d44d9$0$32611$db0fefd9@news.zen.co.uk...
>> Hi,
>>
>> This is getting really annoying now. During high speed, high bank turns
>> the tail is kicking out. Just replaced gyro and servo and it's holding
>> really well, except for this kick. It does it in both directions.
>>
>>
>>
>> It can kick up to 45 degrees at times. From the ground it looks like a
>> severe radio glitch. I know it can't be because I can reproduce it every
>> single time, different directions, different piece of sky etc.
>>
>>
>> It doesn't do it in slower, shallower turns as often or harshly but you
>> can see it if you look hard enough. I'm learning to not freak out when it
>> happens, very difficult to watch the bird sat there convulsing.
>
> The fact that it doesn't do it in shallower or slow turns would tend to
> suggest to me to back off the sensitivity a bit as it is treating your
> harder turns like a sudden weathercock movement and it is trying to
> compensate for them...or in this case overcompensate...back off the
> sensitivity and try a few flights with it then...see how you get on.
>
> I don't fly with a gyro myself but I do know exactly how they work. (I
> learned to fly heli's long before gyro's were on the market and I
> currently have 3 Heli's)
>
>
> --
> Regards........Mark
> (BlueWaveStudios)
> www.scale-models.co.uk (Moderator)
>

Thanks Mark I'll try that

Andy

[Andy Beetz]

"Andy Beetz" <the_flc@REMOVETHISzen.co.uk> wrote in message
news:42427e3d$0$8745$db0fefd9@news.zen.co.uk...
>
> "Mark Stevens" <spamspamspam@spam.com> wrote in message
> news:d1t0rg$gmk$1@newsg1.svr.pol.co.uk...
>>
>> "Andy Beetz" <the_flc@REMOVETHISzen.co.uk> wrote in message
>> news:423d44d9$0$32611$db0fefd9@news.zen.co.uk...
>>> Hi,
>>>
>>> This is getting really annoying now. During high speed, high bank turns
>>> the tail is kicking out. Just replaced gyro and servo and it's holding
>>> really well, except for this kick. It does it in both directions.
>>>
>>>
>>>
>>> It can kick up to 45 degrees at times. From the ground it looks like a
>>> severe radio glitch. I know it can't be because I can reproduce it every
>>> single time, different directions, different piece of sky etc.
>>>
>>>
>>> It doesn't do it in slower, shallower turns as often or harshly but you
>>> can see it if you look hard enough. I'm learning to not freak out when
>>> it happens, very difficult to watch the bird sat there convulsing.
>>
>> The fact that it doesn't do it in shallower or slow turns would tend to
>> suggest to me to back off the sensitivity a bit as it is treating your
>> harder turns like a sudden weathercock movement and it is trying to
>> compensate for them...or in this case overcompensate...back off the
>> sensitivity and try a few flights with it then...see how you get on.
>>
>> I don't fly with a gyro myself but I do know exactly how they work. (I
>> learned to fly heli's long before gyro's were on the market and I
>> currently have 3 Heli's)
>>
>>
>> --
>> Regards........Mark
>> (BlueWaveStudios)
>> www.scale-models.co.uk (Moderator)
>>
>
> Thanks Mark I'll try that
>
> Andy
>

Well, I lowered the gain and if anything it made the problem worse. I can't
increase it because the tail starts to wag.

Any other ideas?

Thanks

[Leif Thomson]

Hi Andy,

It might be the auto hub/oneway letting go. Since the Evo 30 doesn't have a
driven tail, if your mast starts to slip in the oneway, more engine power
will suddenly go to the tail. At knife-edge, there is less force between
the mast and hub (pulling on the lower Jesus bolt). Easy to dissasemble to
see if there's been slippage.

Other things to check include:

Gryo mounting - Is it likely to stay on in all orientations?
Fuel lines and pickup - If you have an engine "hiccup", it can induce a tail
problem.
Glitching - Check your radio and connections. Not likely if it's fine at
hover, but still possible.

Leif




"Andy Beetz" <the_flc@REMOVETHISzen.co.uk> wrote in message
news:423d44d9$0$32611$db0fefd9@news.zen.co.uk...
> Hi,
>
> This is getting really annoying now. During high speed, high bank turns
the
> tail is kicking out. Just replaced gyro and servo and it's holding really
> well, except for this kick. It does it in both directions.
>
>
>
> It can kick up to 45 degrees at times. From the ground it looks like a
> severe radio glitch. I know it can't be because I can reproduce it every
> single time, different directions, different piece of sky etc.
>
>
> It doesn't do it in slower, shallower turns as often or harshly but you
can
> see it if you look hard enough. I'm learning to not freak out when it
> happens, very difficult to watch the bird sat there convulsing.
>
>
>
> I'm running a CSM 420 micro (was using a CSM 360 before but just wouldn't
> hold in HH) set to 68% gain. Tail servo is a GWS S19CL aka Supertec
S09CL2BB
> (0.09s/60deg and 7kg torque). On the recommendation of CSM to maximise the
> amount of servo travel, the servo horn is 12.5mm. The tail blades are 85mm
> fun-key carbon tech.
>
> The engine is an OS32SXH with weston genesis one piece running factory
carb
> settings on 15% wildcat and an enya no3 plug. It is running very very
> nicely, lots of smoke, but not running rich. It sounds very nice and
smooth,
> no raspiness to the note at all.
>
> Head is running about 1600 rpm, I've got no wag in the hover, FF or even
> FFF. It's just the turns
>
>
>
> Any ideas? Any more information required to make a judgement?
>
> TIA
>
> Andy
>
>
>