Hog Bipe – Wing Construction Complete

I have been picking away at the wing construction on the Hog Bipe on and off. Sheeting the wing tips went smoothly and I am happy with the end result.

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The lower wing is built in two pieces and glued together to obtain the proper dihedral. One little trick I used was to cut a block of scrap wood with the dihedral angle for the inner wing rib. This allowed me to position and clamp the rib in place before gluing to the spar. The first photo below shows the block against the kit supplied dihedral angle gage. The second photo shows it in use.

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The rest of the lower wing construction was uneventful and came out straight and true with the right dihedral.

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I bought my kit off e-bay, so I am not really sure when it was made, but I was fortunate enough to have one that included the parts for the optional dual aileron servo setup in place of the single servo in the original kit. The dual servo setup is much stiffer and is less likely to have flutter problems. My only deviation from a stock build so far has been to add a couple of paper tubes for the aileron wires and to use 2 inch wide fiberglass tape t reinforce the lower wing joint instead of the 1 tape supplied with the kit.

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The plans call for using medium or thick CA to saturate the tape weave. I chose to use epoxy instead. This was my first experience using fiberglass cloth and epoxy, and I considered it a small scale trial run for glassing a balsa plane. I sprayed a light coat of 3M-77 adhesive on the glass and laid it down between two strips of masking tape. I chose BSI Finish Cure epoxy. This is similar to laminating resin and was available at the my LHS. To ensure that the epoxy would flow smoothly and to get a good cure, I pre-heated the bottles for 10 seconds in the microwave before mixing. I applied the epoxy with and acid brush and spread it smooth with an old gift card. I rough sanded with 80 grit and applied a second coat after an overnight cure, sanding out with 80 and 150 grit after full cure.

Overall, I am happy with the result. Structurally, I am sure this will be plenty strong. Cosmetically, I am satisfied for this application. It sanded out quite smooth, and would be a good surface for painting (if I was going that direction). I did end up with a few dry spots where the epoxy did not wet through the fiberglass fully, but I know what to look for now and should be able to avoid that in the future.

The last major step was to shape the ailerons to the tip. This also went smoothly with no real surprises or major problems. One minor problem was that one of the supplied aileron blanks did not have a well shaped rounded leading edge – a few minutes with a long sanding bar took care of that.

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Next up is to start in on the fuselage, but I will need to order my motor so that I can properly drill the firewall first.

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