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Old 11-09-2010, 01:39 PM
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BMatthews
 
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Default RE: Gentle Lady wing rib patterns?

Paul's sketch was intended to show you HOW to generate your own ribs for the tips, not the actual measurements. It would be up to you to measure off the marks and redo the locations of the spar notches.

The way to tell if this is how Carl did it would be to measure where the highest point on the root panel rib drawing is located and then measure off and draw the line for the last tip chord length. Measure from the new bottom like to maximum height point and see if it's the same % of chord. If it is then you can use his trick to draw all the tip ribs you need. And if it passes muster when the high point being within 3 to 5% of the proper chord point then you're good to go with that method. From there you just need to offer up the ribs to the leading and trailing edges and mark and cut the spar notches. It's more work but it won't take as long as waiting for ribs to arrive.

As I recall from the set of plans I have squirrelled away the tip ribs are not shown on the kit plan. And I seriously doubt that there are many folks around that would bother to trace them out during the building of the glider. So without buying the RCM scratch building plans it's either Paul's method or use a reducing photocopier to reduce the section shape and then mess with fudging the leading and trailing edge shapes. Frankly I'd suggest that Paul's method is the way to go if you want to keep the model faithful to the original because the photocopier will reduce the leading and trailing edge thickness too much to build easily even though it's a more accurate airfoil transition that way. If you do find that the high point shifts back a little too much on the tips then a few swipes with a long sanding block can reduce the rear of a bunch of the tip ribs all at once to shift the high point forward.