Jim,
This isn't about keeping the wing straight, but it's another aspect of the Shark 402 worth considering early in the build.  The controls on mine are extremely sensitive.  Even with a 2 oz shaft weight on the Brodak .25, and about 25 degrees up and 25 down elevator deflection, it takes a narrower handle spacing than I like to hold it steady in level flight.  If there is a next one (which there may be, because it flies great, turns tight without stalling, and looks terrific), I would build the nose about an inch longer, move the hinge line back about an inch (more stabilizer, less elevator, same overall horizontal tail area), and use a 4" bellcrank to allow a wider handle spacing for more positive control feel without excessive control sensitivity.  Aside from that, the S-402 is a real sleeper among medium-size flapless stunters worthy of more attention that it has received, IMHO.

Kim Mortimore

This design was meant to compete with any other 400 inch design.  The airfoil and very large Tail Volume Coefficient (TVC) are a key factor in the overall effectiveness.  I would assert that there are a lot of people who get into the thinking that a handle has to have a certain spacing and the plane needs to be "adjusted" to fit the handle.  Conversely, I say, adjust the handle till the feel is good.  DO NOT let your preconceived notions about handle spacing get in the way of having a great flying experience.  I have flown planes with 2" spacing and others using a 4" spacing.  I usually end up with about a 3" spacing, but that is just how it works out most of the time.  We have flown the Shark 402 and about the only consideration is to lengthen the nose if not able to get good light wood for the tail parts.  Also, when using a OS FP/LA 25, the stock factory muffler can be used to adjust the CG, or a lighter tongue muffler can be used if the CG needs to be shifted back some.
BTW, this airfoil is the same I used on my Corsair and that flies very well.  Similar TVC on both planes.
Pat Johnston
Design Studios
Skunk Works

Jim

I used a few little blocks glued to the glass with PVA carpenters glue to locate the spar and a levelling bar to support the TE of the ribs. I pin the parts to the spar and the levelling bar when it is necessary. I pull the LE into the birdsmouths on the ribs with a 1/2" aluminium angle, some rubber bands and popsickle sticks behind the spar. It's really quite simple.

When finished, you just remove the blocks and the bar with a scraper and start the next project.

If the ribs have supports under them, just glue them to the glass, cut the ribs off the supports when ready and remove the supports with the scraper.

Cheers, Geoff