stunthanger.com

General control line discussion => Open Forum => Topic started by: Rob Killick on April 19, 2006, 08:38:31 PM

Title: "LUCKY" Horn Boxes ?
Post by: Rob Killick on April 19, 2006, 08:38:31 PM

I'm just looking through my RSM "Lark" plans and I've come across an item on the plans calling for "LUCKY" boxes for the flap hinges .
The flaps and elevator are built up asemblies , but I'm not familiar with the "LUCKY" boxes .
Ummmm ,
What are they ?
I'm sure they are mentioned in the "build" booklet , but I'm not sure , as I don't have it handy right now ...

Title: Re: "LUCKY" Horn Boxes ?
Post by: Charlie Pate on April 19, 2006, 09:23:38 PM

Lucky Boxes are a sort of rectangular box that allows you to use one  flap horn on a swept forward trailing edge in a wing.
It allows the arms to slide from side to side in the flap as it is moved up and down eleminating binding and springiness (such a word)and helps to make smooth accurate controls on a plane with swept forward trailing edge .
 Hope this helps -- best I can do !

Title: Re: "LUCKY" Horn Boxes ?
Post by: Andrew Hathaway on April 19, 2006, 11:17:20 PM

In the case of RSM kits, he supplies parts to build a reinforced box around the flap horns arms that is built into the flap.  It basically allows for free movement and flap tweaks.  The kit should have a couple pieces of composite and maybe plywood in the hardware kit for this. 

Title: Re: "LUCKY" Horn Boxes ?
Post by: Andrew Hathaway on April 19, 2006, 11:22:49 PM

Sorry for the fuzzy picture but you should be able to make out the boxes in the hardware package.  Basically the U-shaped basswood? piece is the middle, the composite material makes up the top and bottom.

Title: Re: "LUCKY" Horn Boxes ?
Post by: Rob Killick on April 19, 2006, 11:30:49 PM

Thank you , both m for the greatr descriptions and the photos , too :)
You've both , opened my eyes  ;D