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Building Tips and technical articles. => Building techniques => Topic started by: Jim Pollock on January 16, 2007, 03:33:59 PM
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Just checking to see if the Skylark method of tabbing the spar it a good enough way to keep a wing straight when building?
Jim Pollock ???
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OK I'll bite on this, whats the Skylark method ??
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It's using removable tabs on D Tube spars to aid in getting the wing built straight.
Jim Pollock ::)
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Just checking to see if the Skylark method of tabbing the spar it a good enough way to keep a wing straight when building?
Jim Pollock ???
Jim,
I built a Skylark from the Smith kit, and in a word, NO, the tabs are not sufficient to do a good job of building a straight wing. They are fine as far as they go, but that is only for the first half of the wing. The tabs do you no good when it's time to flip the wing over to do the second side.
Bill Byers, who was Ed Southwick's protege, drew the plans, and could probably explain how to build a straight wing this way, as I'm sure that he and Ed built many straight wings that way. I don't know if Bill monitors this forum or not.
I'm a firm believer in building a wing in a jig, on plate glass, and not removing the wing from the jig until it is completely done.
My wing had a warp in it after doing the first half. What I had to do was to fabricate about 6 "cradles" from balsa, and secured the wing to them to complete the second half of the construction. Even after all that extra work, the wing did NOT come out straight.
My suggestion would be to use one of the current systems in use today that allows the wing to be completely build while in the jig....e.g. the Millennium system, rods, or a perimeter jig block system. Give it some thought....with all of the excellent choices available, there is no reason to compromise and build a wing that is only "good enough".
Cheers.
Warren Wagner
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Sounds like the VooDoo method.
The trailing edge was taped flat to a table. Several of the ribs included little triangular extenstions that set flat on the table and aligned the ribs to the TE. This method only works well on rectangular wings. I still use it for simple wings.
The MidWest PT-19 had a great idea. I've never seen it elsewhere.
The rib stampings had an extra cut, lengthwide, below the CL of the ribs. With the bottom piece removed, the ribs set flat on a board. After the ribs, LE, TE, and top spar was assembled, you would turn it over, glue the cutoffs back on, and install the bottom spar. PERFECT.