Building Aero 3D Day 22: Top Spars Glued

Main Spar & Spar Glued Weighted to dry

On January 29th we started with getting in the two W-HW-1, 1/4” x 3/8” hardwood cut to 11/2” length in place that slide through the rectangular openings in the W2 ribs. These are the two ribs that sit close together, one on each end of the wing, where the servos will eventually go. These were glued into place using medium CA, placing glue along the outside and inside where the hardwood and rib meet.

Peter thought this idea was good, and may use it in the future, as we believe the idea behind it is to provide greater support for the servo and allow it to be closer to the control surface. In this aircraft, because there is going to be so much force there is a servo per aileron.

Once that was set we moved on to the main spar, that we glued into place along with the smaller spar in the front. For this we used wood glue as we wanted to have lots of time to play and get things positioned properly. Speaking of positining we trial fitted the spars first lining it up such that the gussets (reinforcing the scarf joint) only crossed one rib, minimizing the sanding required. Once determined I widened the slot by sanding to accomodate the extra width from the gussets.

Once done for both we applied glue into the slot on each rib for the main spar and then using the pencil marking placed that location back into the widdened slot of the one spar. We then ensured the spar was sitting down in all the other ribs. We also double checked with a square to make sure everything was, well, square. This was then repeated for the other spar.

Weights were then added, seen on top, as well as along the trailing edge as a counter balance. We then double checked to make sure everything was sitting down properly as do not want the wing to warp. This can be seen in the feature image above. The result after the glue has dried can be seen below.

Main Spar & Spar Glue has set
Main Spar & Spar: Glue has set

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