Aviation Coming Eventually

As soon as I kinked my second tube I knew I would need more to get two good wingtip bows, so I placed an order for three 7' long pieces of tubing. I only needed about 6' to make one bow, but there is almost no leverage for the last of the bend unless you add some excess. I bought three in case I messed another one up beyond saving. Happily, Wicks Aircraft still had the tubing I needed for $1.05 a foot. About $50 and two days later I had my tubing and borrowed a conduit bender from work. I took a scrap from my kinked tubing and tried bending it with the conduit bender; INSTANT KINK. Ooookay... now what?  I read some more from Tony Bingelis' Sportplane Construction Techniques , quoted below. "Thin wall tubing is more difficult to bend successfully because it is very quick to flatten and buckle" The wingtip tubing is .028" wall; the tubing used in the rest of the fuselage is .035" wall or greater. "The larger the diameter of the tubing, the ...

  Now that we're all caught up we can continue.   On Monday I laid out the template for the wingtip bows. This was made a little trickier because the dimensions are to the inside of the tubing, but the Zero position at each end is at the outside of the tubing. There are no dimensions for the endpoints of the inner curve, they just have to be extrapolated.     The dimensions are given from the tip rib at various stations, every 2 inches for the leading edge, and every 6 inches after that. I laid out on a piece of lauan. A nail was driven in at each point, and a thin strip of 1/16" plywood was sprung around the nails. You have to eyeball the curve to make sure it looks smooth, or "fair." This is the stage where you start extrapolating the end points; you make the line look right and make sure 3/4" tubing will fit the rib. In my case, one of the points was about 3/16" too far in to create a fair curve. This was shifted outboard and everything else worked...

 This will be a catch-up post to fill the gap between "Parts Coming Together" and where I am now. Last we left off I had the ribs test-fit on the spars. If memory serves, I had to disassemble the wing to make room in the garage to work on the Prius. Shortly thereafter the last of the mechanics tools Cheyenne inherited moved in and made working in the garage difficult until they were sorted though and somewhat organized.   I decided that the remaining, uninstalled spar doublers should be pre-drilled to make the epoxying and assembly easier. They were each tacked into place temporarily with aircraft nails, drilled through from the backside, checked against the appropriate fittings and labeled.   There are various spruce reinforcements throughout the wing that were cut to rough size from the "bargain bag" lumber I ordered from Aircraft Spruce. I was able to get all the pieces I needed and have a little leftover still. That was quite a pleasant surprise. Some of th...