Fuselage Completion
Fuselage Completion |
|
|
|
|
Date: 13 June 2002 - 16 June 2002 |
Chapter: 15.0 Fuselage |
Section: Fuselage |
The upper canard cut-out was made during our Head Start week. I find it terrifying to make big cuts like this on my expensive bird, but it's fairly straight forward. Just stretch the pre-marked lines down to meet the lower cut-out line. This forms the "doghouse". You can't tell from this picture (see below), but this fits very nicely when the canard is in (which required hand-sanding the radius for an entire evening....)
Upper Canard Cut-Out
Here is a picture of the fit of the "doghouse" cover on the canard after adding a rain gutter under.
Canard Cover Fit
Here are some pictures of us making the rain gutter. This support is optional (not called out in the plans), but has two functions. First, it keeps the shape of the cover in line with the fuselage, but secondly it keeps any moisture that might migrate through the crack from dripping on the avionics. Instead it will (hopefully) be forced to drain to the sides of the fuselage, and there will be a drain on the floor against the canard bulkhead to allow any water to drain free of the fuselage. The flanges are made of Triax, with two layers in the center section.
Making Doghouse Flanges (inside)
Making Doghouse Flanges (outside)
Doghouse Flanges - Finished
For the bulkhead reinforcement we cut 8 8"-18" pieces of Triaxial lengthwise, and trimmed it into an "L" to fit the canard cut-out. The sections overlap the opening by 4" above and below, and extend onto the bulkhead by 5", 2 plys each.
Canard Bulkhead Reinforcement - Bulkhead Side
Canard Bulkhead Reinforcement - Fuselage Side
In this section we need to make a attachment point on the back side of the canard to accept the torsional load of the wing. In order to do this we made a jig out of 1"x4" covered with aluminum foil tape to make 3"x3" pads to later accept a bolt. First we sanded the canard where it will get glassed, bondoed the dog house to the canard in the proper position, then bondoed the 2 boards to the backside and the bottom of the doghouse as shown in these pictures. As a part of this installation, we sighted the concentric torque tube opening by shining a laser point light down the elevator hinge openings and opening a channel for these to slide down, and then we gradually cut the elevators back to clear the fuselage throughout their travel.
Sanding Canard Bonding area
Elevator Torque Tube Cutout
Setting Doghouse Position
Preparing to Glass Doghouse
The canard attachment is made of 3 plys of 3"x12" TRIAX, 2 sets on each side. The first layup is set on the canard and up 3" to form a pad, the second is laid on the doghouse and overlays the 3" pad. We foil taped the doghouse so that it can be removable for access to the avionics in the future. We plan to use a car hood latch to secure this later, and we prepared the surface with micro and BID to smooth the transition.
Finished Attachment Tabs
The mating surface on the fuselage is laid up against a jig that you have to make accept it, shown here.
Canard Aft Tab Jig
You then need to layup 3 ply of 3"x12" TRIAX horizontally against the jig, the 3 ply of 6"x12" vertically to tie it all togther. This section is trimmed after curing to taper from the 3"x3" pad to the fuselage side.
Canard Aft Tab Layups
The only remaining thing for the aft canard tab then is to drill a 1/4" hole through both pads and install a nutplate for to accept the bolt.
Canard Forward Tabs - In the newly (2/2003) revised manual, forward attachment tabs were called for, for additional support. After discussing the issue with the factory, we elected to install them even though it wasn't required (this was not issued as a "KPC", or kit-plans-change, that would indicate a mandatory fix). These were created in a similar manner to the front tabs, with the exception that the canard tab was made first, and the fuselage tab was laid up against the canard tab later. That's because the front of the canard opening is angled, and it would be difficult to get a nice squared tab. As you see here, a (duct tape protected) board was bondo-ed across the front and underneath the canard with the doghouse on, and triax was laid up on both the canard top and doghouse side (which was also protected with aluminum tape). Once cured the doghouse and boards were easily removed from the lay up.
Canard Front Attachment Tabs
After the canard attach tabs and finished, you can finalize the attachment of the canard cover to the canard. I'd tried for several days to come up with a slick way to do this without any screws. This is the sort of thing that gets a builder into trouble, when vanity overcomes sense. What I tried to do was this, take a pair of automotive hood latches and turn them on their sides, and set the bolt into the doghouse. Then, when each side was lowered the bolt would be captured and BOTH hold the cover down, and pull it in side-to-side. There would be a release mechanism in the cockpit which would allow the cover to "spring" out of it's fixtures. Where to start....
First let me say that there's a lot of not-so-straightforward geometry here. The cover is curved up and down while the fuselage/canard are getting wider, and there's not a lot of play in one of these latches. But I made groves for the bolt, and backing plates for the latches, and tapped hardpoints for the bolt to attach to the cover and started bondoing things into place to try and get the geometry just right. What I've come to know a few things hence, here are my top ten reasons YOU the potential Velocity builder SHOULD NOT DO THIS.
Here endith the lesson, but since a picture is worth a thousand words, here is my sorted tale of auto latches.
Needless to say, we reverted to 2 screws per side with two nutplates. Then the cover was sanded, and the canard was protected with duct tape while we laid a radius of FLOX and covered it with one ply of BID cloth to fair the cover to the canard.
Canard Cover Finishing
After finishing up the canard fitting sequence of tasks, we went back and cleaned up the top of the canard where we'd sanded if during the work steps. Here we filled the void between the new doghouse junction and the canard with micro and contoured the canard in this area.
Canard Cleanup
Another item that doesn't really have a home is the seal from the canard/doghouse/fuselage. There is a gap on the rear of the canard from the doghouse to the top of the elevator torque tube that must be sealed. Since the fuselage needs to be open for the torque tube to side down into position while mounting the canard, we've mounted a piece of triax onto the bottom of the canard that will lay flat on the side of the fuselage and seal this opening.
Torque Tube Seal Area
Torque Tube Gap with Canard
Torque Tube Seal Plate
Completed Torque Tube Cover
OK, I didn't like how I did the torque tube close-out after playing with it for awhile. It was flimsy, and it make it hard to get the canard in and out of the plane easily, so I went back to the more standard configuration. This has to you build the removed section back onto the canard. First a piece of scrape fuselage glass/foam board is carved to fit the opening (I made a cardboard cutout of the appropriate shape) and attached to the canard.
Attaching the plug to the canard
Next, the gap and the edge of the foam are sealed with micro. Finally, the torque tube hole is drilled, the elevators are installed, and the torque tube opening is closed with the same micro slurry mixture.
Closing gaps with micro
Closing the torque tube gap
To reinforce the firewall where the engine will be mounted, and to tie it into the fuselage and wing spar more thoroughly.
Inside, the sides get two layups each, 2 ply of triax 6"x18" which is laid up about 6" onto the firewall. One is set horizontally just above the spar, the other at at 45 degree angle to just barely tie into the spar. I say about 6" since the instruction imply 6", however that would put the layups on the window (a bad thing indeed), I moved them slightly more onto the firewall. The upper layup is 4 ply of 6"x8", with 4" on the firewall.
Inside Firewall Reinforcement
On the outside center of the firewall, 2 plys of 4"x4" triax are applied opposite the previous layup.
Outside Firewall Reinforcements
The seat belt hard points are fairly time consuming. First, each seat gets for seat belt hard points, the inboard side gets one for the belt receptacle, and on the outboard side there's one for the inertial reel, one for the the shoulder belt, and one for the lap belt. We've elected to install the same 3 point inertial belts in all four positions. The factory installed the front shoulder hard points for us in the carbon beams, and the rear shoulder hard points are just through bolts installed in the spar's angled bulkhead. The other three per seat are AL blocks (about 1"x2") that are drilled and tapped for 7/16" bolts and floxed and BID (3 layers) onto either the keel or the fuselage side. Once the layup cures, the hole has to be re-drilled and re-tapped. Say goodbye to a whole weekend....
Floxing Hard Points in Place with Velocipoxy
Finished Hard Points BID and Tapped
Rear Seat Belt Hardpoint
The seats are being upholstered by www.oregonaero.com, which includes installing the two setting seat heaters that we purchased from Sports Imports, but we need to install the switches. These are pop-in switches, so we just drilled a 3/4" hole and popped them in just in front of each pair of seats.
Front Seat Heater Switches
Rear Seat Heater Switches
One option that we saw and really liked on the factory aircraft (the Dash-5) at Osh Kosh was the interior hand holds like on cars. We decided to go with the VW style like in our Jetta because the color match is perfect, and they have a really nice retraction action.
The forward overhead beam was installed by the factory, so once we had the switch-panel ready to go, we completed it by installing the panel with 4 screws and nutplates.
Since the premolded engine cooling NACA ducts don't seem to be covered elsewhere in the manual, I'll include them here. Much of the cutting was completed during Head Start, though I did cut the overheard fresh air duct at home. Then they're all fitted up and held in place. The engine naca's had been set with pop rivets for the trip to Ohio, which was sufficient. The fresh air naca was set with glass bubbles and held with tongue depressors. Then all three were given a radius underneath with the aforementioned glass bubbles, and then layed up with BID. Fairly straightforward, though somewhat time consuming, but I just love the more "visible" changes to the plane. Also note that all three got a fair amount of sanding once they were cured. The fresh air naca needed to have the premolded section sanded down to the roof line, which was fairly simple. The large engine naca's, however, had a definite tilt to their flanges that made them visually pucker in comparison to the roof line. I filled the offending area with microballons and sanded, filled and sanded, and got to something I think is close. I will probably cover this area with Cabosil later for wear. Also note that the fresh air scoop needed to have it's inlet ramped back into the fuselage roof for good flow, and this area was covered with microballons and BID.
Fresh Air Scoop Hole Cut
Tongue Depressors to Hold Pressure on NACA During Bonding
NACA Scoops with BID Layups
Covering the Ramp Foam with BID
Cutting the Foam Covering BID back after Cure
After we flipped the plane for Fuel Strake completion in Chapter 9, we went ahead and fitted the overhead fresh air duct since it was convenient. Special Report - ROLLOVER.
Overhead Fresh Air Duct Fitting
Fitting Duct w/Overhead Panel
Fitting Overhead Lights and Vents
Next we fit the lights (from a late model Jetta) and eyeball vents. The beauty ring on the vents were too big so we trimmed them, and they'll be covered later with leather. Also, the Jetta dome lights had a quick-connect plug, so we had to cut them open, solder wires to them, and them fill the connector with silicone to make our connections. Quite laborious. Also we trimmed the upper lip down and sanded the "automobile" silk screens off. (For information on the "Fading/Theater Lighting" module we installed, please see Doors under Pilot Security Latch).
Installed Overhead Plenum
Once the plane was back on it's gear, we wired the lights up and tested them....
Night Lighting from Overhead
Builder's Data Plate Installed
~ End of Chapter ~ End of Section ~