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tail problem

Posted: Sat Nov 15, 2014 4:59 pm
by Tony
yes ive got another problem to solve.... i cant see the wood for the trees here...

i went flying today, well tried... i have got a short video which i will post if need be. flight lasted 10 seconds...

i have lost right tail authority, its probably a stupid mistake ive made setting the tail up..

spooled her up, got it about 5 inches of the deck and it just piro'd left, right stick made no difference.

so with heli on deck i spooled up again, just short of takeoff speed, moved rudder left, was fine, quick response, move rudder right and although i get full pitch it has no effect on tail movement...

so on the bench i checked tail blades AGAIN.... with tail facing me, throttle hold ON. i move rudder stick left, leading edge of tail blade goes right.. and visa-versa...move right and tail goes left..

next test, move tail by hand and watch tail blades, move tail left and blades go right, and visa-versa..

all these tests i do pre-flight. along with swash checks

bet its simple really, its doing my head in

Re: tail problem

Posted: Sat Nov 15, 2014 6:12 pm
by danhampson
check for excessive bend in the tail push rod i have had the same issue with 450's. everthing looks ok without load on the bench but once the tail is under load the rod bends.

Re: tail problem

Posted: Sat Nov 15, 2014 6:52 pm
by Tony
danhampson wrote:check for excessive bend in the tail push rod i have had the same issue with 450's. everthing looks ok without load on the bench but once the tail is under load the rod bends.
Now that sounds plausible as I have the rod in a tube rather than the rod guides.... Nice one Dan I'll check that now...thanks mate

Re: tail problem

Posted: Sat Nov 15, 2014 7:08 pm
by Marius
Reversed gyro direction maybe?

Re: tail problem

Posted: Sat Nov 15, 2014 7:14 pm
by KevG
You've had this flying though haven't you Tony,

Re: tail problem

Posted: Sat Nov 15, 2014 7:18 pm
by Graham Lawrie
Tony, i had a similar issue, and what threw me was that the tail was not leading edge authority, which if you look at Lee,s video and set it up to that, it would be wrong:)

You need to know if your tail is leading edge authority:) Lee mentions it in his video:) If you are going clockwise that could be the problem:)

Re: tail problem

Posted: Sat Nov 15, 2014 7:39 pm
by Tony
Marius wrote:Reversed gyro direction maybe?

Don't think it's reversed Marius, if I put left stick on rudder, the leading edge goes right, I'm sure this is right...lol

Re: tail problem

Posted: Sat Nov 15, 2014 7:40 pm
by Tony
KevG wrote:You've had this flying though haven't you Tony,
Yes Kev, it was flying the other day albeit with little power but I had control of the tail...!!

Re: tail problem

Posted: Sat Nov 15, 2014 7:43 pm
by Tony
Graham Lawrie wrote:Tony, i had a similar issue, and what threw me was that the tail was not leading edge authority, which if you look at Lee,s video and set it up to that, it would be wrong:)

You need to know if your tail is leading edge authority:) Lee mentions it in his video:) If you are going clockwise that could be the problem:)
Now this is confusing.....lol. Is Lees vid wrong because that's how I set it up... Main rotor turns clockwise and tail rotors turn anticlockwise....

Here's a pic of tail..
image.jpg
image.jpg (1.53 MiB) Viewed 4402 times

Re: tail problem

Posted: Sat Nov 15, 2014 7:52 pm
by Derek
This sounds very similar to what's going on with Dustin's 450. I have tail authority in one direction, under load, but not in the other direction. However, when the helicopter is just sitting at rest, I can move the rudder stick in both directions and the tail slider will move from the left to the right and back and forth. Odd!!!

Re: tail problem

Posted: Sat Nov 15, 2014 7:59 pm
by Marius
The belt is twisted in the front, making the tail rotor turn "backwards" - making my theory about gyro direction correct. Twist the belt up front in such a manner that the tail rotor spins forward, turn the tail blades, and you should be good.

My thoughts at least :P

Re: tail problem

Posted: Sat Nov 15, 2014 8:04 pm
by Lee
Tony wrote:
Graham Lawrie wrote:Tony, i had a similar issue, and what threw me was that the tail was not leading edge authority, which if you look at Lee,s video and set it up to that, it would be wrong:)

You need to know if your tail is leading edge authority:) Lee mentions it in his video:) If you are going clockwise that could be the problem:)
Now this is confusing.....lol. Is Lees vid wrong because that's how I set it up... Main rotor turns clockwise and tail rotors turn anticlockwise....

Here's a pic of tail..
image.jpg
If you are following my video Tony by looking at the leading edge of the blade, you are doing it right.
The problem Graham is talking about, is when people look at the slider. Some helis have leading edge control tail grips.
this would mean the pitch slider would move opposite to the norm.

So you don't need to worry, as it sounds like you are checking it right.
Is everything still smooth by hand?

Re: tail problem

Posted: Sat Nov 15, 2014 8:07 pm
by Graham Lawrie
Yup Lee:) thats what i meant lol:)

Re: tail problem

Posted: Sat Nov 15, 2014 8:13 pm
by Tony
thanks guys, the tail blades go anticlockwise with a clockwise main rotor, so this is correct isnt it?? so it wont be the belt im sure.... this was flying the other day....

i always have to watch that vid of yours Lee just to be sure... lol... yes its exactly as your video, i can see where Graham thought it may be wrong... cheers Graham though pal.. yes Lee everything smooth as silk on the tail...

Derek, ill check this out later, check the tail rod mate.... ive put 2 tail rod guides on i got from align as part of the rod kit, i have a feeling Danny boy was right ...lol

thanks guys, hopefully this thing is going to fly soon..... I'm probably not going to be able to test it tonight now as I had to CA glue the rod guides as they weren't tight on the boom....

Re: tail problem

Posted: Sun Nov 16, 2014 9:08 am
by Graham Lawrie
Keep us posted Tony:) always interested in tail issues as they can be hard to sort:)

Re: tail problem

Posted: Sun Nov 16, 2014 9:12 am
by Tony
Graham Lawrie wrote:Keep us posted Tony:) always interested in tail issues as they can be hard to sort:)
Will do bud, I'll be out testing today

Re: tail problem

Posted: Sun Nov 16, 2014 11:49 am
by Tony
well ive replaced the tube i was using as a tail rod guide with the proper align guides. but still have very little right tail authority, left is great and instant....

short video so you guys can see... just to clarify video a bit, when you see the tail moving slowly to the left thats me giving FULL right rudder, and when it quickly moves right thats again me giving stick inputs

http://youtu.be/WPDloGEyZtk

im going to remove the night blades and controller on top of head.... this thing flew well the other day, so puzzling

Re: tail problem

Posted: Sun Nov 16, 2014 2:15 pm
by Marius
Link not working. Here's the correct link: https://www.youtube.com/watch?v=WPDloGEyZtk

Could you film the tail slider while inputting left and right rudder?

Re: tail problem

Posted: Sun Nov 16, 2014 2:42 pm
by Superbad
The tail blade grips are back wards
The leading edge of the blade should be on the same side as the slider link

Re: tail problem

Posted: Sun Nov 16, 2014 3:30 pm
by Tony
i wonder what i did wrong with the link....

anyway guys, i appreciate all your help, shes now flying !!!!!!!!!!!!!!!!!!!!!

ive been chatting to Lee nearly all day on this problem via skype. the problem was the tail blade pitch was more on full left rudder than on full right rudder.

simple solution was to move the tail servo down the boom about 2mm, this gave an even pitch both left and right rudder... i had to adjust Kbar settings for tail servo as the changes made it bind with full right... she seems to be OK now

this is just a short video flying in the garden, far too small an area for any prolonged flight, but enough to see the tail locked in. ill take her to the field later

thanks for everyones help and suggestions, i really do appreciate all your time..

https://www.youtube.com/watch?v=PkAZbZO ... e=youtu.be

if this link isnt working either can someone explain what im doing wrong, im just copying the address line to here... thanks