Stock blades and KBDD 104mm not as good as carbon fiber blades

[hybriden]

Yes. His name is Steinar Walaker. If you want I can pm you with his info.

[skartun]

Yes please :-) nice to know about more compass pilots in the area :-)

Sent from my GT-I9100 using Tapatalk 2

[Trulsen]

Ordered bls251 now. Hope that solves it

// Truls

[Trulsen]

Originally Posted by Trulsen

Ordered bls251 now. Hope that solves it

// Truls

And YES! Finally the tail is rock solid and no tail wag. So far the BLS251 solves all issues, so this discussion is no longer any problem
. I guess i were wrong when saying the kbdds did not work properly! Sorry for that!

[latte]

Grats on solving the issue!

I wonder if chinese weights, would also have worked, if torque is the problem.

[Ah Clem]

Trulsen,

"I guess i were wrong when saying the kbdds did not work properly! Sorry for that!"

I am very pleased that you got the issue resolved sir!

Any chance I could request that you change the name of this thread to reflect the final outcome?

[OverTemp]

Originally Posted by latte

Grats on solving the issue!

I wonder if chinese weights, would also have worked, if torque is the problem.

I would also like to know... I think we are at the limits of servo power with this baby. We need a better name for them though. Sikorsky weights or something.

[alexmit]

Originally Posted by OverTemp

I would also like to know... I think we are at the limits of servo power with this baby. We need a better name for them though. Sikorsky weights or something.

I seem to remember seeing weights on the newer prototype tail Compass was working on when I was in Birmingham. I haven't heard or seen anything on the progress with the new tail since. I wish there was a sticky where Compass would post when new update parts and kits come available for purchase. Not necessarily in stock at a store, but coming on the boat from China to the retailers.

[Rob43]

Agree with OT. I am very surprised the wimpy torque output of most tail servos can manage this tail. I disconnected the control rod to on the bench at speed (no mains) and holy smokes. I thought it would take a come-along to pull it. What creates such a very high centering force?

[Ah Clem]

"What creates such a very high centering force?"

What you are probably seeing is "Tennis Racket Effect", where the centripetal force tries to straighten the blades out so the tips are aligned with the plane of rotation. The tail blades usually turn at five or six times the RPM of the head, so the forces are considerable.

Chinese weights do help counteract the effect..

Several people, including Finless, have made some pretty interesting posts on "Tennis Racket Effect".

[Rob43]

I've known of this phenom for a while now, but to clarify, why are some tails like the 7HV generating more "TRE" than others? Just the design of components (ie, mass, location of center of mass, etc.)?

[Ah Clem]

The Compass tail blade grips are pretty light, so I doubt they are contributing to the Tennis Racket Effect.

If they had Chinese weights designed in, that could reduce it, though.

[alexmit]

Originally Posted by Ah Clem

The Compass tail blade grips are pretty light, so I doubt they are contributing to the Tennis Racket Effect.

If they had Chinese weights designed in, that could reduce it, though.

Take your tail blades and main blades off and spin up your heli and work the tail slider by hand. You will find that the initial part of your quote is off base quite a bit.

[Caleb White]

Originally Posted by alexmit

Take your tail blades and main blades off and spin up your heli and work the tail slider by hand. You will find that the initial part of your quote is off base quite a bit.

They are so light and narrow compared to most 700 tail grips, that nothing, not even the screw and nut contributes much to C-Weight counter-acting... therefore the plastic arm, ball and link are the furthest point out and that is what causes the TRE on the grip. I suppost a large portion comes from the blades too and it would be interesting to experiment with root-hole positions from leading edge.

The prototype plastic new grips are large, putting more mass on the sides, plus the C-Wts sticking out. Even though plastic, they probably contribute a decent amount.

[alexmit]

Originally Posted by Caleb White

They are so light and narrow compared to most 700 tail grips, that nothing, not even the screw and nut contributes much to C-Weight counter-acting... therefore the plastic arm, ball and link are the furthest point out and that is what causes the TRE on the grip. I suppost a large portion comes from the blades too and it would be interesting to experiment with root-hole positions from leading edge.

The prototype plastic new grips are large, putting more mass on the sides, plus the C-Wts sticking out. Even though plastic, they probably contribute a decent amount.

Caleb,
Is the testing on the new tail still ongoing or is it closer to completion? I know you guys have been working on it for quite a while now. Is it to the point where one of you could post pictures of it?
I'd love to see the new main gear too, but I'm pretty sure that is fairly early in stages of testing.

[Caleb White]

Not sure of everything going on with tail developments. Maybe still revising parts to try.
The gear pic just posted in:
https://www.helifreak.com/showthread.php?t=417448
It could still change as well.