AJUSTABLE LEADOUTS

Hello,
It would seem that again I have a question regarding my "not so well known" kit of a P-51 Mustang, (I repaired the warped fuselage, cut it and replaced the bad section),so, question in point, how do ajustable leadouts work, where do I put them, pictures would be great. Yes I have crap plans that could have been better drawn by a three year old with crayons while doing 80mph in the back seat of a car, lol. Please help.

As always, all and any advise is welcome.

Regards, Geoff.....Torham

Generally adjustable leadouts will allow you to fine tune the yaw of the plane for better tracking through a maneuver.

The mechanism generally consists of a piece of plywood such as 1/8 lite ply, with a grove down the middle and a slider which the lines pass through. This is mounted like a rib somewhere between the last rib and the wing tip. A slot from the plywood piece to the wing tip has to be made to allow room for the leadouts to exit the wing. The plywood piece should be place so the leadouts can be adjusted over a range from slightly in front of the CG on back. The slider is made of a material such as nylon with brass eyelets for the lines to pass through spaced about 3/4 to 1 1/4" apart with a central screw assembly to clamp the slider in place.

To determine an starting point hang the plane by the leadouts and adjust so the nose is slightly down.

Brodak has an adjustable leadout assembly which will save you having to figure out how to build one.

Geoff,

Brodak carries them, and GreatHobbies.com sells them. You can see a picture at the following link: http://www.brodak.com/shop_productdetail.php?ProductID=BH-760&catagory=82&maincatagory=1

Tim

LAST EDITED ON Jan-25-04 AT 10:27 PM (CDT)
 
I make mine just like this:

http://www.aeromaniacs.com/Adjleadouts.htm

Glue the stationary part to the inside of the last rib and make the wingtip hollow. This works great.

One other thing: put in a bolt that's too long and crush the tip threads so it can't back all the way out.

Regards,

Brett Buck's bench trimming article pretty much explains - Where your lead-outs should go?
http://www.aeromaniacs.com/Benchtrim.htm

>Brett Buck's bench trimming article pretty much explains -
>Where your lead-outs should go?
>http://www.aeromaniacs.com/Benchtrim.htm

Hey, that's on the Internet? I probably ought to update the figures.

By the way, the original article has been trumped by the existence of Pete Soule's "LineII" program, available for download on this page:

http://www.geocities.com/AMA271/Aeronotes/lines.htm

The 1.5-2.5 degrees mentioned in the article is still about what it usually comes out for typical 40-60 sized airplanes. In fact, if you are trimming to keep the airplane tangent all the time, and you put the leadouts where this program says to, you will be within about 1/8". If you are very far off what the program says, you either have a misalignment, some other trim problem, or are screwing up. Leadout position is really not as random of variable as it's sometimes made out to be.

The title of the post prompts me to reply. This is the first sliding block adjustable leadouts. I used them on the Mustang shown when I built it in 1967. The first magazine publication was this one, the Bearcat article in March 1970 American Aircraft Modeler, which also contained the description and logic for the reversed bellcrank. Since adjustibility is the whole point, I've found it enough to center a 1 1/2" slot on a typical 1/4 chord spar and let the adjustment do the rest. Optimum line spacing is 1/2" - 3/4".

I make up my mounting plate out of pieces of 1/8 sq spruce. Easier for me than cutting out a piece of ply. I use pieces of the yellow plastic tubing that comes with Pylon brand leadouts rather than grommets. Also, I space the lines 3/4 in at most. Other than that, I'm on the same page as everyone else. Adjustable leadouts are one of the major innovations in CL.

Thanks to all for the great advise and links. Leonard, your help via the PEM was great as always.This forum is invaluable, please keep it up.
Regards as always,
Geoff.......Torham