Discussion Servo horn length F5B wings

[jjmouris]

Can i get a show of hands on who uses what hole on their servo arms?!

In particular, on the Avionik B05/06/08 what hole do you use on the aileron servo arm. Assuming Dymond D60 in this case, there are only 2 holes on mine as the last bit has been removed of the servo arm.

If i use the second hole, i can have the controll rod clear of the wing skin. If i use the inner hole, i would have to put a little bend in the rod and/or clear some of the skin away round the servo arm.

If i use the outer hole, i am only using less then 50% of the available servo throw to get full deflections (including spoilers and snap flap). My controll surface arm length is just short of the provided cover with the hole just forward of the hinge line, so it can not be any larger.

I find one of the two servo's has relatively a lot of slop and this is causing to much slop on the aileron for my liking. Hense i am thinking if i use the shorter arm hole i will use more like 100% of the available throw and reduce the effect of the slop in the servo.

No pictures at present, might add later.

Joe

[dhauch]

I always go with the inner most hole, or the shortest horn possible.

this will give the best mechanical advantage, keep things tighter, and use more of the servo travel.

sound like your going in the right direction.

dave hauch www.rc-builds.com

[carpetbomb]

Originally Posted by dhauch

I always go with the inner most hole, or the shortest horn possible.

this will give the best mechanical advantage, keep things tighter, and use more of the servo travel.

sound like your going in the right direction.

dave hauch www.rc-builds.com

So, when you do that - do you bend the arm, or remove skin from the wing? Assuming you have clearance issues.

-
mike

[dhauch]

Originally Posted by carpetbomb

So, when you do that - do you bend the arm, or remove skin from the wing? Assuming you have clearance issues.

-
mike

are you bottom or top driving ?

dave www.rc-builds.com

[carpetbomb]

Originally Posted by dhauch

are you bottom or top driving ?

dave www.rc-builds.com

I haven't luck doing any top driven setups. I can't seem to get the cuts right, and/or what type of horn/brass fitting to use on the aileron/flap

But for the sake of this conversation and learning - let's just say both. Curious how it's done.

-
mike

[dhauch]

Originally Posted by carpetbomb

I haven't luck doing any top driven setups. I can't seem to get the cuts right, and/or what type of horn/brass fitting to use on the aileron/flap

But for the sake of this conversation and learning - let's just say both. Curious how it's done.

-
mike

okay, if your bottom driving this one, just remove some of the skin.
i'm guessing it's hitting in the aft portion of the servo bay .

you shouldn't have to for ailerons, but it's common to have to slot the skin for flaps, because the servo horn is mounted aft.

dave www.rc-builds.com

[George Shering]

Originally Posted by carpetbomb

So, when you do that - do you bend the arm, or remove skin from the wing? Assuming you have clearance issues.

-
mike

Both if necessary. As someone said before use the innermost hole possible and work hard on the pushrod lengths and transmitter settings to get the maximum throws for the up aileron brake. I use 100% of the throws in both directions.

[jjmouris]

Yeah, it's just when i saw this picture i got confused. As it clearly shows the second hole is being used. I also have seen a lot of other Avioniks put together in similar fashion and just wanted to see who is doing what.

http://www.rcgroups.com/forums/attac...7&d=1211429250

Also i note the servo cover is much higher then needed at the servo horn side if you use the inner hole. Still a little oversize if you use the second hole. So maybe i should make some new covers that will fit more flush.

The B08 uses bottom driven surfaces as it has top hinges on both flaps and ailerons.

On my RW2 i used top driven linkages as it has bottom hinges. As you can see, i do know how to do a clean install.

[jjmouris]

Before and after pictures.

Much better now!!!

Only very slight bend in the controll rod and a little bit of work on the hole in the wing to allow everything to clear.

[jjmouris]

Here are the full deflections as of now.

Max snap flaps and full spoilers.

There is a little more left on the servo and linkage but the hinge line seems to be not so flexible past a certain point. I'll test fly it first and see if i need any more then this.

[jjmouris]

Sneak peak of the flap linkage.

Coult not resist doing it "differently".

I just can't stand huge servo covers.

[MrMagic]

nice one you could slide some 2mm id carbon rod + cyano over the linkage to stiffin it up

[Darron]

Originally Posted by jjmouris

Can i get a show of hands on who uses what hole on their servo arms?!

Joe,
When I used the outer hole on a D60 - I found I had a floating neutral. Both ailerons. It was a problem with the servo which always would overshoot and stop, in the overshot position. Using the inner hole would make this problem less obvious. Used that servo type many times and that was the first time I saw that problem, was also the first time I used the outer hole too. Swapped for the Hyperion servos.
D

[jjmouris]

I have no idea what the dia is of this metal rod i am using. Was going to put some carbon rod on the top of it and wrap it with kevlar string. But i can't really get these linkages to flex so might not bother. The flex that is there is in the Nylon gears of the D60 servo's.

The RW2 has got 4x Hyperion DS09AMD in it and those don't flex or slop at all.

[MrMagic]

Originally Posted by Darron

Swapped for the Hyperion servos.
D

Agree with Darron on that, soz I misunderstood your post but anyway it looks like 2mm rod