JC's Planes and Projects

GSDK Wing Construction

The wing is built upside-down over the plans. Speaking of plans, they include only the drawing for the left wing. The instructions state that "you don't need a drawing for the right wing" because of the slotted leading and trailing edges. I found this unacceptable. To allow myself to build an accurate right wing I turned the left wing plans over and inked in the lines. The construction is very straight-forward. Don't forget to make the required modifications to plywood ribs 2 & 3 to allow accurate alignment of the wing tubes. Wing spars are 3/8" square balsa with 3/32" sheer webs.

Here is a shot of the top of the right wing before sheeting. Also visible above is the two cardboard tubes that constitute the wing mounting. Two rather heavy 7/8" wood dowels slide through the fuselage and into each wing. The smaller brown tubes are homemade servo wire tubes. Note the use of two standard servos to drive the ailerons. Running these servos at 6 volts will give me 100 oz-in per aileron.

The wing construction took a little longer than anticipated due to the lack of balsa in the kit. The supplied sheeting is the best quality that I have seen, there just is not enough of it! I had to go to my local hobby shop to buy six sheets of 4 x 3/32 x 48 balsa sheets to finish covering the wings. That is an additional outlay of $20.00! I was also shorted stock for the leading edge of one of the wings. Another trip to the hobby shop and another $6.00.

The addendum to the instructions changes the method of mounting the wings. The plans indicate the old method of using rubber bands. The revised method is to use drilled and tapped hardwood pieces. The tap size is 10-32. The front hardwood wing mounting block is shown above glued with epoxy to the cardboard tube and the inside of rib #3.

Here is the rear hardwood wing mounting bolt. Make sure you make this change before sheeting the top of the wing or you will end up cutting holes in the sheeting - like I did on the left wing. I chose not to tap the hardwood block, but rather drill a clearance hole for the nylon bolt and then tap the hardwood dowel. This will make it easier to find the hole during assembly at the field, and reduce the amount of screw-turning.

This is the top of the right wing showing the location of the wing mounting blocks with nylon retention bolts and wing dowels in place. Make sure that the hardwood dowels are completely inserted into the cardboard tube before you drill though the block and dowel.

Here is a test assembly of the fuse, wings, and tail components. The left wing is nearly complete and shows the top sheeting and cap-stripping in place. The tail is all stick built and easily constructed. Unfortunately, I built the fin/stab out of 3/8" balsa according to plans. There is an obscure note in the addendum to the instructions that says "all surfaces are 1/2". A fast look over the included balsa and parts list showed insufficient 1/2" balsa for the fin/stab and that threw me off. I had to re-build the fin/stab. I also made the beveled and rounded pieces of the fin/stab out of 1/2" square balsa that I had to buy from my local hobby shop. The instructions would have you bevel and round 3/8" x 1/2" balsa. The 1/2" dimension is the thickness of the part and beveling or rounding this size stock would remove more than 1/3 of the balsa! I thought that this was an accident waiting to happen as the part would be severely weakened.