Science

Wheel Skirts, not pants my students say. The plane is a she.

Believe it or not building the wheel skirt is one of the most time consuming difficult parts of the construction. Each wheel skirt comes in two parts. Trim and straighten the edges till each half mates smoothly. Place each half of the skirt against the appropriate landing gear. Measure from the floor to the front tip and from the floor to the rear tip of the skirt so each is 9" from the floor. Tape the collar of each half to the rear landing gear strut. Mark the bottom of the skirts in front and behind the tire. Cut the holes a little undersize and trim to fit when installing the wheel skirts. These access holes will be where the wheel projects through the wheel skirt. Remove skirts. Sand the inside and outside edges about 2" wide with 40 grit paper. Duct tape the halves together on the outside. Cut strips of fiberglass 3" wide or use 3" fiberglass tape. Glass the skirts together on the inside seam with 3 bid fiberglass and epoxy. After cured remove the duct tape from the outside and glass the outside with 2 bid fiberglass. Fill and sand.

Bracket

Fabricate a small bracket out of 1/8" x 1" x 8" flat aluminum bar. The bracket will screw into place on the inside of the Main Axle Backing Plate. Drill a 3/16" hole 1" from each end of the bracket. Place the inside half of the skirt against the bracket making sure that the tips are 9" from the floor. Mark the location of the holes onto the inside of the skirt with a sharp pencil. Trace around the outside of the tire onto the inside of the inside wheel skirt when secured in place with 10/32" screws. Remove and trace a pattern 1.5" larger than the tire tapering to the top of the skirt collar. Cut the patter out. This is your mounting plate for the skirt.

Create a hard point for each of the two holes on the inside skirt mounting plate with a quarter and 2bid glass. Drill out the hole after cured. Rivet nut plates on the inside of the 1/8" x 1" aluminum bracket where the two mounting holes were drilled. Attach the axle spacer on the wheel and screw a 3/32" screw into the tip. This hold the outer skirt away from the tires. Mount the skirts and adjust them so that they are level front and back with front and back tips 9" off the floor. Adjust the skirt so it is inline with the plane strait forward by chalk lining the a mark down the center of the belly of the fuselage. Measure from this line to the front tip and rear tip. Make each the same distance and the skirts are inline. As you adjust the skirt it will bend the aluminum bracket to fit. Trim and sand the cut out for the tire till there is a 1/2" gap between the skirt and the tires all the way around. Once the skirt is adjusted tap the outside if the wheel skirt where the tip of the spacer meets the inside of the skirt with a hammer. This will leave a mark where the screw touches. Drill a 3/32" hole in this mark.

Remove the skirt and duct tape a 4" wide section around the landing gear strut where the skirt collar reaches. Mix up micro glass and place a 1" thick layer around the inside of the skirt collar. Attach the skirts. The micro will form to the shape of the strut on the collar. Glass the outside of the skirt collar to the duct tape on the strut with 3 bid and micro. Let cure. To remove cut a smooth line from the front and back of the collar through the glass with a razor. Sand fill and prime the skirt so the collar and the edge around the flange mesh with the shape of the skirt.

Cooling Scoops

Velocity states that the brakes can get real hot so I created intake scoops and exhuast vents to use ram air to cool the breaks. Mark the shape and location of the scoops on the inside skirt in line with the disc breaks. Cut the bottom and rear lines of the scoop. Wedge the bottom rear corner of the scoop in 1.5". Place a mixing stick against the inside of the scoop from the front to the back corner. Mark a line across the stick where it touches the cut edge of the skirt. Cut the wedge shape out of the stick. Glass the wedge in plce between the scoop and the skirt holding the lower edge open. Cut a 1" high 3" long slot in the rear tip of the skirt for the exhaust.

Front Skirt

Attach a mounting bracket 1/8" x 1" aluminum to the front of the landing gear with 3/32" screws. Make sure it holds the skirt tips 9" off the floor. Drill the holes and tap. Sand the edges so the halves mesh together. Cut the hole for the tire.  Glass the inside and outside of the skirt with 2bid. Draw a line from the hole in the top of the skirt for the landing gear strut to the back edge of the tire hole. Cut the skirt in half along this line.

Sand the inside edge of the front skirt 2 inches wide. Duct tape the inside edge of the rear skirt. Duct tape the halves together. Glass in a flange from the sanded inside edge onto the duct taped edge of the skirt with 3 bid. Let cure. Mark scew locations on the back half of the skirt 3/4" from the edge. Drill the holes with a 3/32" bit. Remove the halves and rivet the nut plates in. Screw a 10/32" screw in the end of each side of the front axle. Install the skirt. Adjust the it so the tips are level 9" off the floor, it is inline with the fuselage and there is 1/2" clearance around the tire. Tap the side of the skirt with a hammer where the axles meet the skirt. Drill the hole. Add hard points on the inside of the skirt where the axle holes are.