DaSH PA -- Dead Simple Human Powered Airplane: Gluing Center Spar Biscuits and Sleeves

Center Main Spar with biscuits and end sleeves glued in place, biscuit locations lightly clamped to maintain circularity

Last week we started building the first wing section, by gluing the biscuits in the center spar sleeves, and the biscuits inside the center spar, and then gluing the center spar sleeves on each side of the center main spar (the middle main spar sections slide over these sleeves in the field).

We'll be gluing biscuits and sleeves inside pairs of wing spar parts each build day now, letting them dry while the parts are plugged together on their sleeves so that when dry, the spar parts will slide easily on and off the sleeves. So for example, we'll next be gluing biscuits and outer sleeves into the Middle Main Spar sections, and letting those dry while plugged onto the center section sleeve. Then we'll do the Outer Main Spar section on each side in a similar fashion.

Before we do the biscuiting, we have to do a lot of prep work, marking where the biscuits are on the outside, so we know where to squeeze to hold the biscuit in place while withdrawing the biscuiting tool, as well as marking the eventual location of the wing ribs, so we can locate them when we do the next step of gluing the ribs in place. The prep work of marking the spar actually takes longer than gluing in the biscuits, which takes about an hour or so for the 6.7 m spar sections.