stomper

My Feedback: (20)

Any one know of any manufactures that sell a floating bell crank hardware?

Not sure which way to go. Floating bell crank or the new SWB self adjusting servo tray for a CA 2.6 Yak.

Thanks

Firenza

l just made up my own.

SitNFly

My Feedback: (54)

Very nice work. Any more details; plane, servos, servo arms, bits used in the floating assembly?

JohnVH

My Feedback: (38)

Here is my 40% 3W plane setup.

EJB

If SWB sold it,it would probably be $150.

Sure-link has it.They call it the "VonLinsowe System".

Shortman

My Feedback: (21)

LOL your exactly right on the price. The new SWB unit (which is totally awesome) is $147. For some reason, I just don't think a sheet of aluminum and some anodizing should cost that much.

ptgarcia

My Feedback: (36)

JohnVH,

I'm sure you're aware of this but in your picture it looks like the top swivel ball link is bent quite a bit, like the connector has been screwed in a little too far. Could this possibly cause a future failure at this point? Just don't want to see you lose that beauty...

JohnVH

My Feedback: (38)

Yeah, its bent, I got it that way and flew the heck out of it.. so its not going to go anywhere.. Thanks for looking out for me

Firenza

it's in a Composite 2.6 Yak.
3" Nelson Hobby full servo arms [Bolt on ]
They have to be 3" to match the stock rudder horn [ no slop, lock to lock ]
The rods are 2mm or 2.56x9" with 2mm ball links at the servo end.
spring links the other end.
The bell cranks size is important, with small bell cranks, if one servo stops working you will still have
half+ rudder. The longer the bell cranks, the less rudder you will have.
The down side with short cranks is, lf a servo locked full tilt, the planes going in. But thats no different
than the stock CA way.
IF you use longer cranks, you will be safe on a lock over, but you will have no rudder if one just free wheels.

DKjens

My Feedback: (50)

Firenze, so I still don't understand why you would rather have a floating bellcrank system where, if one servo locks over full, you go in, than a system where, if one servo locks in any position, you would have at least anywhere from neutral rudder to half of full deflection, and definetely be able to land your plane in one piece.
I will set up my 2.6m Yak with floating bellcranks on the rudder, but will try make all the arms and bellcranks the same length.
DKjens

stomper

My Feedback: (20)

I have never set up a floating bell crank, but thought the benefits were, the ability to use unmatched servos and some degree of fail safe.

I take it I'm wrong on the later.

I would like to see what you come up with DKjens.

So at this point, the SWB self adjusting servo tray is the safer way to go?

Thanks for the help guys!

Firenza

Hi DKjens.
Trying to get my head round this one. Do you agree that the longer the
bell-cranks the less rudder movement you will get if a servo fails.
With my short cranks, l am getting 3/4 rudder if one servo fails, witch is quite
handy in a low knife edge pass. lf l lock one full tilt, it is only pulling the rudder over
by 1/4 so l was wrong to say its going to put the plane in???
l have to say you have got me thinking ,so l am going to get some longer cranks tomorrow
to see what happens.
Firenza.

DKjens

My Feedback: (50)

Firenza,
Firstly. Maybe we are thinking differently about what the airplane should be able to do after a failure has occured. I am thinking in the lines, that if a failure occurs in the air I will be able to feel it, and will make the decission to land and investigate. I would never attempt knife edge loops or high alpha knife edge passes, if I suspected that anything was wrong.

Secondly. We all know how ultra rudder responsive these planes are, heck, low rate is max 50% of high rate, and knife edge is still possible. So, with even very little rudder ability, or perhabs just being able to neutralize the rudder, normal flying and landings are possible. On the other hand, if the rudder can not be brought fully back to neutral, because of a short bell crank and a hard over stuffed servo, normal flying and landing will be, at the least, tricky.

As pointed out, yes, floating bell cranks negates the need for identical or matched servos and eliminates the possibility of the servos working "against" each other. But why not design the system so that in case of one total servo failure, the plane can still be flown and landed safely?

DKjens

Firenza

DKjens.
l was not suggesting that you do a low KE pass if you suspected some thing was wrong,
but it would be handy if you were half way through the maneuver with 75% rudder when
it failed.
Are you saying that with the right length cranks, one servo can go full lock and the rudder can
still go to neutral and maintain some rudder movement. if so l missed that one.

What happens if one elevator servo goes full lock or one of the servos on a dual aileron setup locks.
Firenza.