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Building Tips and technical articles. => Building techniques => Topic started by: larry jaconetta on May 12, 2006, 09:27:18 AM

Title: help-help-help
Post by: larry jaconetta on May 12, 2006, 09:27:18 AM
 I have built at least 5 ringmasters in my life, and i never had a problem with the solid leadind edges they give you, but this latest kit, has one of the leading edge halfs has a slight warp in it. I tried wetting it, and jigging straight, and it worked for about 2 days!!! now the warp is back! not as bad, but its there!! what do you guys do to straighten out a warped piece?

                                      larry j
Title: Re: help-help-help
Post by: Bob Reeves on May 12, 2006, 02:34:13 PM
Is it a RSM kit? If so contact Eric and he will make it right, good company.

If it's a Sterling S-1 you are kinda stuck with the wet and hope. Try putting a little ammonia in the water you wet it with, work out some way to jig it a little past straight, let it sit overnight and hope for the best.
Title: Re: help-help-help
Post by: RC Storick on May 12, 2006, 05:14:50 PM
I have built at least 5 ringmasters in my life, and i never had a problem with the solid leadind edges they give you, but this latest kit, has one of the leading edge halfs has a slight warp in it. I tried wetting it, and jigging straight, and it worked for about 2 days!!! now the warp is back! not as bad, but its there!! what do you guys do to straighten out a warped piece?

                                      larry j

Steam will relieve the power in the wood!
Title: Re: help-help-help
Post by: wwwarbird on May 12, 2006, 06:15:28 PM
 Also, when you are wetting (or steaming) bend and hold it past center until it has dried (or cooled) and usually you'll find the happy medium. I've had it work for me. ;D
Title: Re: help-help-help
Post by: Bill Little on May 12, 2006, 07:58:30 PM
A method that works, althugh there may be better ways, is to take a razor saw and make cuts about 3/4 way through the LE on the convex side of the piece.  Then secure the piece dead straight and put glue in the slots while keeping pressure on it until the glue dries.  It's trial and error as to how many cuts to make, but as you cut and bend you will see where and how many cuts to make.

I did this to a Giant Stuntmaster LE piece to straighten it and it has lasted for years.  I put the cut side to the outboard wing and the cuts on the bottom.  What little bit of weight added became less tip weight needed.

One thing about it, the "warp" will never come backin that area!  y1
Title: Re: help-help-help
Post by: Tom Perry on May 12, 2006, 08:07:26 PM
Larry,

I usually make my own.  See the thread I started and no one answered here:

http://stunthanger.com/smf/index.php?topic=612.0

or go directly to the source by following this link:

http://groups.msn.com/NorfolkAeromodelers/howto.msnw?action=ShowPhoto&PhotoID=107

If you don't have a router table may be a friend has one.   :)
Title: Re: help-help-help
Post by: Bill Little on May 13, 2006, 08:58:46 AM
HI Larry,

Another thought.  Ammonia releases the lecthicin (I'm told) in the wood which allows the structure to "take" a new setting when it dries.  I know ammonia works.  The problem is, the wood takes on some extra brittleness when its dry.

I still prefer my "physical method" of cutting and straightening since the warp is now eliminated with out trying to make the wood do something that it orginally didn't do.
Title: Re: help-help-help
Post by: old fart on May 22, 2006, 10:58:15 AM
 LARRY
GO TO YOUR LHS AND BY A NEW STRIGHT LEEDING EDGE  THEY ARE CHEAP USE THREE FINE TOOTHED HACK SAW BLADES TAPED TOGETHER FOR RIB SLOTS PERFECT 3/32 SLOT
Title: Re: help-help-help
Post by: Jim Thomerson on May 22, 2006, 03:04:45 PM

When building older designs which have large solid spars or leading edges, I laminate them out of smaller pieces.  Different ways to to it, but doing a 1/2 square spar of two triangle pieces works well