Control Lines For all you fly-by-wire fanatics!

leadout question

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Old 03-18-2013, 09:08 AM
  #1
jayseas
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Default leadout question

Can you use 1 leadout for both wires?Why not?
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Old 03-18-2013, 09:33 AM
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Joseph Fisher
 
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Default RE: leadout question

When the lead outs are seprated there is little chance that the conectors will tangel and lock the control.
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Old 03-18-2013, 09:51 AM
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jayseas
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Default RE: leadout question

Are there any performance or handling issues, if you would use just one hole for both lines?
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Old 03-18-2013, 11:24 AM
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Jim Thomerson
 
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Default RE: leadout question

One leadout hole is what I do on 1/2A airplanes. I use different length leadouts. I think leadouts should be as close together as you are comfortable with.
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Old 03-18-2013, 01:15 PM
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Default RE: leadout question

Jay, of course one leadout can be used, but JimThomerson is correct in stating that you want one of the wires out of the wing to be longer than the other - an inch or so is the normal practice. The main reason for this is so you know which wire is which when you hook up your flying wires.

Joe Fisher is 100% right in that the main reason for 2 leadout holes is to keep the wires from tangling INSIDE the wing (where you can't see them) and binding the whole thing up. If I were going to use a single hole I think I'd want to make it more of an oval than round to help keep the wires separated.

I, myself, use 2 leadout holes, about 1/2" apart, ANDeach wire is a different length. Has worked for me for more than 55 years.

Dave

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ORIGINAL: jayseas

Can you use 1 leadout for both wires?Why not?
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Old 03-18-2013, 05:35 PM
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Default RE: leadout question

There have been precision pilots/designers who separated the leadouts to get leverage. They knew the airplane would yaw one way on insides and the other on outsides. It's from P-effect and gyroscopic precession and it really does happen. Al Rabe's rudder was created to deal with it.

So there actually have been people who separated the leadouts from each other some distance on purpose. The theory is that the inboard wingtip centers on the 'tight' wire etc.

As for using one hole... Wire has a tendency to wrap. Two side by side will have a tendency to wrap around each other. Being inside the wing, you can't see them to know. Just planning to keep a chosen one forward or back all the time won't do anything to keep them parallel. You'd need to do something to insure they can't entwine. Why bother. Put your two leadouts side by side and you get them close and their separtation is insured.

What do you want to get from just using one leadout guide?
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Old 03-19-2013, 05:32 AM
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Jim Thomerson
 
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Default RE: leadout question

On a 1/2A stunt airplane, there is noticeable yaw on corners with leadouts a half inch apart. On larger airplanes it is not that noticeable. I do use oval holes on 1/2As. I've never noticed a problem with leadouts wrapping. I've been making the same CL mistakes for 60 years.
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Old 03-19-2013, 07:40 AM
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Default RE: leadout question

Quote:
ORIGINAL: Jim Thomerson

On a 1/2A stunt airplane, there is noticeable yaw on corners with leadouts a half inch apart. On larger airplanes it is not that noticeable. I do use oval holes on 1/2As. I've never noticed a problem with leadouts wrapping. I've been making the same CL mistakes for 60 years.
You shouldn't take my observations as a negative opinion of your advice. They weren't offered as such.

Mention of braided wire having a tendency to curl around things is what I noticed on my combat wings. I'd color coded the ends of the leadouts and the lines so it wouldn't matter if the wires were crossed. It mattered one day. At least I think it did. Something hung up on launch in the middle of a fun match. Could have been at the bellcrank. To be safe, I figured there hadn't been any real benefit, but could have been a negative. In fact I quit putting adjustables AND one hole outlets both in my combat wings and went back to 2 guides glued solid. Simple works better for some things.

You and I have probably had a lot of the same experiences over the YEARS.... but we've also had different ones too. Hopefully, us old guys observations will overlap enough we cover everything the younger guys ask about.

Good you mention the yaw that's possible from small stunters. I did a little Magician one time and did what you do with the little guys. It yawed like crazy. It was a perfect test bed to see if swapping the leadouts would help or hurt the yaw. The adjustable leadout setup in the tip was one long slot so I could cross the leadouts. I was using .018s for the leadouts and figured the wear wouldn't amount to anything and there'd be no real friction. It worked.

Different things do different things for different things, don't they.
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Old 03-19-2013, 11:38 AM
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Default RE: leadout question

After experience with racers and stunters, I thought you combat guys were mistaken to have the leadouts so far back. I built a for fun combat airplane with a worn out ST G21-35 and put in adjustable leadouts. It was an honest 100 MPH airplane. The leadouts ended up way back, right where you combat guys put them.[:-]
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Old 03-19-2013, 01:26 PM
  #10
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Default RE: leadout question


Quote:
ORIGINAL: Jim Thomerson

After experience with racers and stunters, I thought you combat guys were mistaken to have the leadouts so far back. I built a for fun combat airplane with a worn out ST G21-35 and put in adjustable leadouts. It was an honest 100 MPH airplane. The leadouts ended up way back, right where you combat guys put them.[:-]

I'm not a combat guy. But I flew it and rat for many years just to get some of my buddies to go to contests with me. I flew stunt but couldn't get them to build those models. Many years ago...... I had a couple of friends who were deep into rat. I'd get the stunt director to cut me loose for one flight if I needed to go race. Same deal with combat at the smaller contests. The buddies mostly helped each other with me filling in. On weekends without contests, we'd do it all as we came to it. Many years ago.... sweet years they were.

Used to run up and down the eastern side of the US to contests. Wore out a couple of cars doing that.

Slow rat and slow combat was fairly popular and a lot of fun. I ran off a series of Yak9s from scratch. Put adjustable leadouts in 'em. Still got a box of motor parts. You did accumulate lots of motor parts.
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Old 03-19-2013, 01:29 PM
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Default RE: leadout question

Oh yeah, almost forgot.....

The aft leadouts were pretty much a function of the thicker lines (.018s iirc) and higher speeds. There was more arc in the bigger diameter lines. But rats ran larger lines too but they also had more engine pulling the drag and more centrifugal force helping straighten the lines.

You know, it just dawned on me why my right shoulder and arm are giving me trouble nowadays.....
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Old 03-19-2013, 01:48 PM
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Default RE: leadout question

If you can get to your bell crank, I wouldnt run leadouts at all. My old Fast combat and 1/2A planes were all done this way. Just hook the lines straight to the the bell crank. Lots less drag on the inboard tip.
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