4-Bulkheads. Bulkheads. December XLR Page 4-1

Transcription

1 Bulkheads December XLR Page 4-1

2 This Page Intentionally Left Blank Page XLR December 2007

3 Contents Chapter Preface Parts List Tools List Supplies List Glass List Process Overview Bulkhead Preparation Locate Bulkhead Placement Install Bulkheads Preliminary Fitting of Parts Bonding Procedures Glassing Bulkheads Engine Bulkhead Engine and Gear Bulkheads Cowl Canard Bulkhead Notes Battery Shelf Landing Light December XLR Page 4-3

4 4.0 - Chapter Preface Parts List Part Number Description Qty MP0501 Bulkhead, Canard 1 MP0502 Instrument Panel -or- 1 MP0503 Canted Instrument Panel 1 MP0504 Wiring Ducts 2 MP0505 Tray, Battery 1 AAC-3-4 Pop Rivet, Small 20 Bulkhead, Firewall 1 Bulkhead, Gear 1 Gear Pockets, Left and Right 2 LLMP Landing Light Holder 1 LLL Landing Light Lens 1 LLAS Landing Light Assembly Hardware Tools List Description Water Level Roll Tape Measure Plumb Bob Clecos Supplies List Description 48" Level Small Level Tubes Masking Tape Structural Adhesive Glass Bubbles EZ-poxy cabosil Flox Glass List Type Size Qty BID 3' x 3" Around Fuselage 6 BID 3 1/2" x 1/2 Around Fuselage 1 TRIAX Floor Reinforcement 2 BID 3" x Battery Tray 2 Page XLR December 2007

5 Process Overview Construction Process Prepare Bulkheads Level & Jig Fuselage Mark Bulkhead Locations Trim Ducts Completion Date Install Bulkheads Dry Fit Bulkheads and Ducts Locate and Fasten Bulkheads Bond In Firewall Reinforce Floor Bond In Main Gear Bulkhead Install Other Bulkheads & Fixtures Prepare Keel for Installation Bond In Canard Bulkhead Bond In Battery Bulkhead Bond in Landing Light holder December XLR Page 4-5

6 4.1 - Bulkhead Preparation Locate Bulkhead Placement Note: There is an index hole in the fuselage flange 1" forward of the airplane. All measurements on the plane include this 1". To locate bulkhead placement inside the fuselage you must level the fuselage upright. (See Figure 4-1a, 4-1b, and Figure 4-2). Use a water level as described in the chapter 1 to place the nose of the aircraft at the same level with a point 10 below the flange at the center of the rear of the cowling. This is the initial leveling on which all future levelings will be based. Take the time to do it right. Be precise. Measure bulkhead locations along fuselage centerline (Figure 4-2). Mark the bulkhead positions on the flange perpendicular to the centerline. The measurements along the flange are approximate and can be used to verify bulkhead location. However, since the fuselage is not perfectly symmetrical, there may be minor differences from one side to the other when the bulkheads are perfectly square. The canard bulkhead measurement is for the forward side position. The instrument panel and firewall measurements are to the aft side positions. Centrally, on the side of the fuselage, about 6" down from the flange, place masking tape and mark a level line on it. Use this line for all future longitudinal leveling. It is a good idea to Bondo a couple of bubble levels on the fuselage floor, one on the longitudinal axis and one on the transverse axis. Make sure they are level, of course. A good place is just behind the instrument panel, ahead of the front seat, to the left of the console. These can also be referred to for future leveling. Place a straightedge across fuselage at the marked locations for bulkheads and, using a plumb bob every few inches across fuselage, mark points to locate bulkheads transversely. Leveling the Fuselage Use a water level at the nose flange and a point 10 below the aft-most cowl flange (either side of the cowl will work) At the factory, we like to attach a sliding bar clamp to the cowl flange, and then mark a point 10 below the flange, directly on the slider on the clamp. A plum-bob will work equally well. 10 in. Aft View, Looking Forward Figure 4-1a. Leveling the Fuselage Page XLR December 2007

7 * Origin of measurements is bolt-hole on the nose flange. Measure and mark all bulkheads on flange of lower fuselage. Measurements shown below are from nose bolt hole to flange, not along the centerline of aircraft. * Pay attention to the aft and forward references. They specify the location of the aft and forward faces of the bulkheads. Aft firewall 159-1/8 Forward canard 43-1/8 Note: copilot side of canted instrument panel is 1-3/4" aft of pilot side 63-1/8 Figure 4-1b. Bulkhead locations on a diagonal referenced to nose bolt hole. Aft instrument panel December XLR Page 4-7

8 Lower Fuselage Flange, where upper and lower fuselage halves separate. Measurement taken from cowl flange as described in figure 4-1a /2 59 C L 10 Firewall (Aft Face) Gear Bulkhead 39-½" Scrap Foam Shims On Saw Horses For fine leveling Figure 4-2. Bulkhead locations referenced to aircraft centerline. Instrument Panel (Aft Face) Canard Bulkhead (Forward Face) * All measurements depicted above are from the nose bolt hole to the indicated face of each bulkhead. They are along the centerline of the aircraft. * It is extremely important that the aircraft be level both transversely and longitudinally for proper installation of the bulkheads. Page XLR December 2007

9 4.2 - Install Bulkheads Preliminary Fitting of Parts Wiring Ducts The wiring ducts have a joggle in one end that corresponds to the end of the foam in the rear of the fuselage. If the duct will not reach the canard bulkhead, the foam will need to be beveled to allow the duct to move forward. Trim the duct flanges to 1/2. Lay the ducts in the fuselage temporarily. As you are fitting the firewall, gear bulkheads, and canard bulkhead, cut the flanges of the ducts off under the flanges of these bulkheads to allow them to go down as far as possible. Firewall There are 3 locating dimples on the fuselage outer skin. One in the center of the pane the other two are on the sides about 2 inches down from the flange. The firewall flange has three (3) 1/8 hole locating marks on it. Drill these out to 1/8. Install the firewall (flange forward) over the ducts and cleco in place. Gear Bulkhead You install the gear bulkhead and the premade gear pockets at the same time. Drill 1/ 4 holes in gear pockets out to 3/8. Set the molded gear pockets in place in front of the firewall. This will give the proper spacing for the gear bulkhead. Notch the fuselage foam to allow the top of the gear bulkhead to come forward. Use a level across the tops of the gear pockets to level them with the fuselage flange. Temporarily set gear bulkhead in place (flange aft). Canard Bulkhead The canard bulkhead and the keel must be fit at the same time. Refer to chapter 6 for keel install. The premarked holes in the canard bulkhead are not used to index the canard bulkhead. Measure 43 1/8 back from the nose bolt hole and place a mark on each side of the fuselage. Install the canard bulkhead at the 43 1/8 mark make sure it is plumb with the firewall and that it is level laterally with the gear pockets. Note: It is very important to get the canard top and gear pocket top to match up laterally. Your center spar and your canard rest on these and this will make sure that they line up laterally. Also measure from the canard bulkhead to the firewall along the flange on each side of the airplane. If the bulkheads are square to each other this measurement will be the same on each side. Cut the flange completely off in the area of the gear door cutout. Go to the outermost edge of the beveled foam on the inside skin of the fuselage. Preparations for Bonding Draw around the perimeters of all of the bulkheads and the ducts with a marker to mark their locations. December XLR Page 4-9

10 Sand all contact areas on the bulkheads and fuselage. Clean thoroughly with denatured alcohol. Bevel the inboard vertical edges of the gear pockets to allow later layups to transition smoothly from the gear pockets onto the firewall. You will want to cut the nose gear door hole out before bonding the canard bulkhead. Refer to section Bonding Procedures Before bulkheads are bonded in, sand each bulkhead around the perimeter and 2 on the fuselage side without the flange. The flanged side of the bulkhead does not need any glassing. The structural adhesive is a 1 to 1 mix, and you will need to add enough Cab-O-Sil and flox to make a pasty mixture like mayonnaise. Canard Bulkhead and Wiring Ducts Reference section Canard Bulkhead Notes when installing. Bond the ducts and canard bulkhead in place with the keel temporarily in place to line things up. Do not bond the keel down. Do the next step before things cure. Using BSP-4-4 rivets, rivet the canard bulkhead to the fuselage with 8 rivets. Use rivets on each duct. Cleco (do not rivet) the portion of each duct that is between the firewall and gear bulkhead. Gear Box Area We will now bond the firewall, gear pockets, and gear bulkhead to each other then bond this whole assembly into the fuselage. Spread adhesive on the contact surfaces of each part and hold them together loosely with a length of 1/4 threaded rod and nuts. Do the next steps before this cures. Spread adhesive on the flanges of the bulkheads and on the contact surfaces of the pockets and install them in place. Note that for the pockets you must spread adhesive on any surface that contacts the fuselage, wiring duct, or bulkhead. Lay a long level across the gear pockets and make sure they are level. The hole through them was drilled to 3/8 to allow some movement to position them properly. Install the center cleco and then the side cleco s in the centering holes in the fuselage and firewall. Coat the cleco s with Vaseline so you can get them back out after cure. Make sure the gear bulkhead is flush with the floor and tighten the nuts on the threaded rod. To hold the firewall and gear bulkhead tightly against the gear pockets, install 3 large rivets (612 AA) on the front and back sides of the pockets. Install them spaced 2 apart horizontally. They should be centered approximately 11-1/2 below the fuselage flange Glassing Bulkheads All bulkheads are glassed with 2 plies of BID approximately 3 wide with the axis at 45 degrees overlapping equally on the bulkheads and fuselage (see Engine Bulkhead below for additional layups). The flanged side of the bulkheads do not need to be glassed Engine Bulkhead The engine bulkhead (ie. firewall) receives a third layer of BID that joins the engine side of the firewall to what will become the cowling flange. Cut a BID strip approximately 3.5 wide. Apply the BID so that it laps 2 onto what will become the inside of the cowling. Lap the remaining portion of the strip onto the rear face of the firewall. Page XLR December 2007

11 Engine and Gear Bulkheads Apply one layer of TRIAX, 7" x 39", major axis fore and aft (the 7" dimension), between the engine and gear bulkheads, centered transversely, running from one duct to the other. This reinforces the floor at this point. Figure 4-6 Triax reinforcement Drill a 1" hole in both ducts just forward of the engine bulkhead toward the bottom of the fuselage for later routing of wires and brake lines Cowl After the firewall is installed you can remove the lower cowling. The upper cowling is removed and flanged in the same way as the lower cowling but you must first install the top fuselage half which is located in the Doors / Windows section. Draw a line parallel to the firewall on the lower fuselage half 1-3/4 away from the firewall. This will be the line that you will your cowling cut line. There already is a cowling cut line that you can use as a reference. Place a piece of masking tape along this spot line to form a smooth, fair line for cutting off the cowl. Start cutting the cowling free about 6 at a time. After you have made the cut attach tongue depressor pieces across the cut with hot glue. Wait until the glue cools on the piece you just cut before you make the next cut. This will keep the cowling lined up properly. Cut the cowling free all the way down to the flanges. Don t cut through the flanges at this time. Place 2" wide duct tape across the fuselage where it meets the aft firewall face, from side to side. Line up the aft side with your cut line. Aft Firewall 1 ply BID 5" wide 2" duct tape 1/8" Figure 4-7. Cowling flange lay-up. 1 ply BID 3" wide 2 plies BID 4" wide Cut line Apply one layer of 3" and two layers of 4" BID tape across the fuselage over the duct tape but just butting into the duct tape radius at the firewall. Put 1 layer of 5" wide BID. This creates the cowl flange. After cure you will need to drill the attach holes before removing cowl. December XLR Page 4-11

12 Drill 1/8" holes through the lip and fuselage 1-1/8" aft of the firewall (or 5/8" forward of the cut line), spaced 6" apart, from the centerline to each side of the fuselage. These holes will become future nut plate locations and are used for clecos while doing various fitting operations. Figure 4-8. Cowling cut line and nut plate holes. Now you can cut through the flanges between the fuselage and cowling. Break the cowl away from the fuselage, sand the edges, remove the tape, and clean up Canard Bulkhead Notes You will use the keel to install the canard bulkhead since the flange on the keel indexes to the canard bulkhead. Use clecos or self-tapping screws to install temporarily for fitting. The canard bulkhead comes as a flanged, premolded part. This makes it easier to fit into it position. Trim the flange to 3/4 wide. The flange will need to be removed in the area of the keel. The keel will be installed in Chapter 6. Outboard battery bracket - top view 5.562" 2.25" * Modify as needed to accomodate battery 7.75" * 1.5" 1.625" Aluminum angle, ¾" x ¾" x.062", 5.562" long Side view 35º.062".75".75".25".5" 1.375" Battery clamp 5.562".125" Drill and rivet for nutplates in two places on back side. Locate using battery clamp with battery.75" in place. Figure 4-9. Battery tray assembly. 1" 7.375" Battery Shelf Assemble the battery shelf and brackets as shown in Figure 4-9 and Page XLR December 2007

13 Canard bulkhead 5-¼" Fuselage Battery tray Figure Battery holder assembly. Sand the bottom of the flanges and the fuselage. Spread an EZ-Poxy/microglass mixture on the bottom of the flanges and position the shelf in the position shown above Landing Light Cut out the inside of the premolded flange for the landing light on the nose of the airplane. Leave a 1/4 lip all the way around the exterior to mount the lens to. Place the landing light holder in the nose of the airplane. Center it from left to right in the hole you just cut and push it as far forward as it will go. You may need to trim the flange off the front of the holder to allow it to slide further forward. When satisfied with fit mark the location for the holder. Remove the holder and sand both the holders flange and the fuselage where it will go. Install holder using Structural Adhesive. You may want to place a weight on top of the holder as the adhesive cures. Figure 4-11 Landing light holder Install three 8-32 screws with nuts as shown in figure The springs that hold in the landing light hook around these screws. It is not a bad idea to cover the springs with rubber or tygon tubing to act as an insulator so you do not accidentally short out the battery. The lens for the light can be installed with silicone after the aircraft is painted. * * * December XLR Page 4-13