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Fuselage

   The fuselage arrived today 4/5/07, this time on a much larger truck!  It came in one huge wooden crate and a 15’ long 2” diameter tube.  Upon opening the crate I found about 10 individually packed sub kits and tons of randomly bent and aluminum sheets.  This project just got a lot more daunting!  The first step is to take inventory of all the parts and hardware. Vans gives you 30 days to inventory the parts, if you figure your you’re missing something after 30 days then you bought it.

   As I look back at my work, with a nearly finished airframe under my belt, I notice little mistakes that could have been avoided had I payed closer attention to detail.  I suspect this is normal for most first time builders.  I have tried to make note of all my known mistakes so that future builders can avoild them.  If something on this page doesnt look right, then please dont hesitate to contact me.

Jig
   My parents came out to St Louis this weekend so I had a lot of help building the fuselage jig.  It really helps to have two pairs of eyes checking these critical measurements.  The fuselage jig is basically a horizontal ladder supported by 6 legs.  The picture shows 6 legs but in the end I used 4 because it makes the jig easier to level.  Its absolutely critical for the cross members to create a perfectly level plane in all directions.  An out of level jig can cause major problems down the road because the firewall and bulkhead locations are referenced to the surface of the cross members.  My jig is level in all directions to less than 1/16”.  Check the photos below for details.

Bulkheads
   Construction of the bulkheads is for the most part straightforward and therefore doesn’t warrant any discussion.  I did however find the firewall to be difficult because the plans leave much to the imagination.  One decent picture would clear things up immensely.  The corners of the firewall, where the extruded aluminum channels and engine mounting brackets WD-302/303 meet, is the most ambiguous part of the firewall.  When you are positioning the brackets make sure you position them on the correct sides, both top and bottom and left and right.  Check the picture below for details regarding the relationship of the L channel to the engine brackets.  Make sure the brackets are set close enough to the firewall flange, mine are set in a little too far.  This caused the side skin to look concaved when it was riveted on.

Framing the Fuselage
   Framing the fuselage is sort of an involved process because everything must be straight in every dimension.  It’s one of those processes where you put it together and take it apart about a dozen times before you drill a single hole.  The seat bottom support area requires the most attention because there are a lot of little details that the plans omit.
Frame Modifications and Tips:

Skinning the Fuselage
   Skinning the fuselage can be pretty frustrating if the bulkhead flanges don’t mate naturally with the skin.  This can be avoided by carefully aligning the height of the bulkheads by tilting them forward or aft before you drill them to the longerons.  You want to stand at one end of the fuse and sight down the bulkheads, adjusting them until they are all lined up.  Next, you want to take the long aluminum push rod tube and slide it along the bulkheads bottoms and sides to double check height and alignment.  When everything looks right, you’re ready to start skinning the fuse.
   The rear lower skin piece gave me some trouble initially because the skin just wouldn’t line up properly with the F-310 flanges.  I ended up making some spacers to fit between the flanges and skin. Most skins are easy, except for the front side and rear bottom skins.  The side skins must be trimmed on all sides and there are tons of rivet holes.  The bottom rear skin is discussed in the bullets below.
   Installing the blind nuts on the upper longeron is a four step process.  First, I drilled #30 holes for the AN509 8R8 bolts, next I clecoed the plate nuts on the inside, then I drilled and clecoed the two #40 holes, and finally I removed the plate nut and enlarged the #30 hole to the final size of the AN509 bolts.  The photo below details most of the steps.
   When mounting the rudder pedal angle mounts pay CLOSE attention to their location.  DWG 24 shows them in the incorrect location, but lists the correct spacing.  DWG 31 shows them in the correct location.  I mistakenly built to the picture and decided to have the rudder pedals cut and welded to the DWG 24 dimensions.
   Removing the fuse from the jig was a 5 person job.  I had three people lifting the fuse while two people pulled the jig out from under it.  This was by far the most exciting step in the build process so far.
   One of the last skin pieces installed is the rear top skin. After synching it down against the bulkheads with rope, I drilled and installed one cleco at the top center of each bulkhead to pin the skin in place. Next, I worked down the bulkheads to and then along the longerons. I was lucky to have the bulkhead flanges mate up with the skin fairly well. If your bulkheads aren’t aligned correctly then you will have to cut the flanges off of the bulkheads and fabricate new ones. I had a friend hold a 2x4 on the outside of the skin while I crawled inside the fuse and drilled through the existing longeron holes. The 2x4 helped pin the skin so that I could drill clean and accurate holes.
   Skin Modifications and Tips:

Panel
   The experimental glass panel market has started to take off recently in much the same way the computer and cell phone industries have over the past decade.  It seems like a new EFIS company pops up every month. I’m predicting inexpensive 3D synthetic vision as well as some king of GPS interfaced with Google Earth type mapping in to come out in the next 10 years or so.  It is for these reasons that I have decided to fabricate a removable panel. Fortunately this has already been done on www.rv-3.com.  You simply order some extra F-302 instrument panel blanks as well as F-803CPP.  You can see how it is assembled in the pictures below.

Seat
   I built the seat steps according to plans aside from one minor detail.  My seat steps slide under the side longeron as opposed to resting on top.  The seat back is pretty easy, just know that the side pieces and F-305 must be trimmed where they touch in order for the seat to recline far enough.  The center crotch strap bracket can be added at this time if you so choose.  I placed a fillet behind each side of the seat bulkhead.  This gave the seat back a much more rigid feel.

Baggage Compartment
   Installing the baggage compartment floor turned out to be easier than I thought.  I just started with some basic measurements and trimmed it down until it fit properly.  I’m going to hold off on cutting the battery hole until I have the battery in hand.  The baggage compartment bulkhead is mounted to F-306 with 6 handmade brackets. Check the pic below for details.
   The elevator bell crank is pre drilled! I cant imagine what it would be like if the whole plane was pre drilled.
Note: Be sure to cut a slot for both flap arms before you install the floor piece.  The plans only have one slot drawn and of course I didn’t catch this mistake until after I installed it.  I had to go back and cut it with a dremmel tool.

Control Mixer and Stick
   The control mixer bearing brackets are pretty straightforward and are pictured below.  After installing the bearing brackets, the control mixer and control stick can be installed.  The mixer and stick require some adjusting before they fit together.  The brass bushing must first be drilled out to 1/4” for the AN4-34 bolt to fit.  The plans have two bolt sizes listed on different pages, AN4-33 and AN4-34, my kit was missing both.  The AND-33 bolt ended up being too short in my application.  The stick carry through tube must also be ground down so that the stick fits into the control mixer.  Now after all of these adjustments everything should fit together right?  Well not really, I found that the stick carry through tube can slide over the control mixer tube.  This results in about 0.040” lateral slop in the stick.  To tighten the tolerances up a bit I decided to slide a washer between one side of the stick and control mixer.   It sounds complicated so I put a picture of the final assembly below.  My stick mixer is about 3/8" too far aft as you can see in the pictures below. Everything works well in this position, however do not mount yours any farther aft.

Flap Control
    I decided to install manual flaps in my RV-3 because I haveheard nothing but good things about them.  Some people say its nice to be able to instantly dump extra lift during the rollout by quickly raising the flaps. The locking mechanism is straightforward and is pictured below.  I was able to get a coworker to turn down an aluminum rod into a button for the end of the handle. The flap deflection locking mechanism is anchored at the top and bottom, as shown in the picture below.  There is a chance your flap lever will hit the side longeron as mine did.  For a simpIe fix I chose to bend it in a vice until it fit.

Throttle Quadrant
   I designed the throttle quadrant with functionality and ergonomics in mind.  The key was to design it in such a way to allow for full flap deflection without any obstruction.  I basically just pieced it together with a bunch of scrap aluminum.  The design would be much more complicated for a 3 lever throttle because the increased width would interfere with the flap handle. It gets screwed to the fuselage in three locations: F-303, F-305, and the fuselage side.

Static System
   I ordered the static port kit from vans and the physical static ports from Cleveland Tools.  The cleveland static ports require a 1/4” ID hose as opposed to the 1/4” OD hose that comes with the Vans kits. After taking this picture I relocated the T connection to the top of the bulkheak in an effort prevent water from pooling in the line.

Mounting the Empennage
   Mounting the stabilizers turned out to be a nonevent.  I would however recommend buying a nice digital level before you attempt this step.  I was able to get the HS incidence right on 0.0 degrees. The VS required the same attention to detail.  I’m pretty sure everything is right on the money, but wont know until I fly it.

Ruder Pedals
   The rudder pedals are pretty simple as long as you get the brackets in the correct position.  The pedals have changed over the years so pay close attention to the drawings.  DWG 24 pictures them in the wrong location, but lists the right dimension.  Drawing 31 shows them in the correct location.  I installed them as shown on DWG 24, which made the pedals impossible to install without any modifications.  So instead of relocating the brackets, I decided to cut and re-weld the cross tube to the correct length.

Rudder Cables
   Instead of the metal rudder pedal cable fairing I decided to lay up a nice one piece glass cover.  This is a great place to hone your fiberglass skills before tackling the HS/VS fairing and canopy skirt. First you want to cover the cable holes with electrical tape, then you want to make a foam pattern and tape the foam to the fuse, and finally you lay up some glass.  Of course if this sounds like too much work, you can simply buy a premade piece online.

Elevator Trim
   I chose manual elevator trim because its inexpensive and simple. The trim fits nicely under the throttle quadrant. The cable is mounted through a piece of L channel that I mounted on the throttle quadrant side skin mount. Check the pictures below for details.

Finish Kit

   Space has become a premium as you can see from the picture below.  It took about a day to inventory and clean up the living room....if you can call it that.  You can see my 27% 3D machine on the table in one of the pictures.  I think I might use that paint scheme on the RV-3.

Canopy Frame
   The canopy frame is pretty simple.  Push to open is opposite from the Blanik I flew in college, oh well.

Cutting the Canopy
   Cutting the canopy out of its mold is rumored to be one of the most stressful steps in the build.  After reading nearly every thread about it on VAF I decided to make the cut.  I used the supplied cut-off wheel and my air drill set at a VERY slow RPM to make the cut.  I also set the apartment temperature as high as I could get it in an effort to make the plexi as soft as possible.  Be sure to shim the freshly cut material away from the mold so the cut off blade doesn't get pinched.  After cutting it to the final size you will want to sand edge down to 400 grit to get rid of any scratches. Just take your time and do it on a hot day.

Canopy Skirt
   The kit calls for bits of aluminum to be used for the canopy skirt.  Well since I don’t have an English wheel or the patients to tackle that job, I’m going to fab up a fiberglass skirt.  I started with a layer of poster board, tape, and modeling clay for the mold.  The skin is made of 3 layers of 8 oz bidirectional glass.  I broke it up into 5 parts: skinny front, large left rectangle, large right, skinny rear left, skinny rear right.  I dovetailed/meshed the seams together for a strong joint.  The skirt is then popped off, cut/sanded to size, and finished with many many many coats of SuperFil.
In an effort to water proof the cockpit I put a bead of silicon between the canopy and canopy skirt.  Final installation required some basswood shims as seen below.

Tail Fairing
   The fiberglass fairing that the kit came with is a joke.  I used pieces of it to form the surface to lay up my own fiberglass fairing.  The lumps of putty (crayola modeling clay) form nice fillets.  I highly recommend you buy Partall Mold Release from Wicks Aircraft.  This stuff is great, you just smear it on whatever you don’t want the fiberglass to stick to.  It dries to a film and comes off easily with acetone or soap and water.  I used 3 layers of bidirectional glass.  The fairing is actually split into 4 quadrants that are meshed together.  I stated with the upper left, then upper right, lower left, and finally lower right.  Don’t be afraid of laying up a one piece fairing; it will come off with a little work.
   As far as physically fastening it to the plane goes, I decided to use MS24693-C50 screws and A3135-8 tinerman washers from Wicks.  I also bought some MS21069-L08 mini plate nuts from Wicks.  You will definitely want to use these because the standard size will not fit between the rivets on the vertical and horizontal stabs.

Landing Gear
   Drilling the landing gear legs is not fun.  The gear legs are made of heat treated case hardened steel.  I drilled a 1/8” pilot hole followed by the final 5/16” hole.  The manual recommends using cobalt drill bits at no more than 15 rpm.  While the cobalt drill bits work great, I found 15 rpm to be way too slow.  I ended up work hardening the metal half way through the first 5/16” hole.  After work hardening the gear leg metal and ruining one cobalt bit I decided to let her eat by cranking it up to 60-100 rpm’s.  What a difference, I was through in about 10 minutes.  Be sure to take breaks and use lubricant to allow the metal to cool.

Brakes
   The manual calls for a single brake fluid reservoir and solid brake lines.  This seemed like a crude design so I decided to use individual brake reservoirs and AN3 stainless steel braided hose.
I bought the following lines from www.speedwaymotors.com:
   91031847-3 two 48” AN# lines
   91031897-3 two 12” with 90 end lines
I also bought two Grove brake fluid reservoirs, model 067-050, from Aircraft Spruce.  The pictures below are pretty much self explanatory. (The missing rivet and bolt in the picture will be added, don’t worry I didn’t forget.)

The Big Move (4/12/08)
   It looks like I have done what I can do for now.  I rented a 17ft truck for the big move to the airport. You can see the whole process in this YouTube video RV3B move.

The BIGGER move (6/08)
   Soon after moving the fuselage to the hangar, my fiance and I decided to move back to the east coast. Fortunately my work paid for the moving costs.  Unfortunately I had to build some really robust crates for the fuselage and wings.  
   I started with the more difficult fuselage crate.  The first step was to install the wooden support in the spar and remove the gear legs. With the fuselage resting on the wood spar support as it did for most of the build, I started to frame the crate.  I made sure to put large wheels on the bottom of the crate so I could easily move it around.  The crate is basically a 2x4 box frame with diaganal braces at all corners and plywood sheeting.  The plywood sheets were screwed to the wood spar support to prevent the plane from moving.  Aparently it was strong enough, because everything showed up 1,000 miles away at my parents garage in one piece.

Wheel Pants
  The stock wheelpants require a lot of trimming before they will fit over the wheel and landing gear.   The rear halves will require more timing around the landing gear than the front halves as you can see below.  After fitting the pants over the wheel you want to drill and cleco the two halves together.   I used 4.25 inch spacing for the screw locations.  Now they can be precisely adjusted and drilled onto the aluminum brackets.  I used a blocks of wood to set the height of the front and back of the pants.   The rest of the angularity adjustments are made per the plans.

Gear Leg Fairings
  The gearleg fairings are installed per the plans.  The upper end of the fairings are held in place with a wood block/metal strap device that is clamped to the gearleg.  The black material under the strap is bicycle tube rubber.  You can see pictures of it below. If your are trying to install the gear legs with the wheelpants already installed, you will probably find the hinge pin very difficult to remove.  To solve the problem I cut the hinge pin in the center and cut a small slot in the center of the fairing.  The pins can then be slid into the hinge through the center of the fairing.  Be sure to make small 90 degree bends on one end of the pins so you can easily remove them.

Gear Leg to Wheel Pant Fairings
   My dad did about 95% of the work on the wheel pant fairings.  The first step is to shape the clay mold and lay up the fiberglass fairing.  The fairing is then cut along the split line of the wheel pants.  In order to prevent the fairing from separating at the seam while in flight, a fiberglass flange was glassed into the rear half of the faring.  The wheel pants are then reassembled so the split line can be dressed with epoxy and microballoons.

Seat
   Premanufactured RV-3 seats are pretty hard to come by so I decided to make my own.  I started with one inch thick sheets of temperfoam from Wicks and spray glue.  So from bottom to top its two layers of 1/4" high density green pvc foam(used for final height adjustments), one layer of firm green foam, two layers of medium blue foam, and one layer of soft pink foam.  The hard PVC foam is great for final 1/4" adjustments because its about 1/3 the weight of temperfoam and can be ordered in various thicknesses.  Everything is glued together with the spray glue thats recommended on the Wicks site.  The sides were trimmed down with my bandsaw until everything was flush.  It turns out that the foam is really easy to sand when its frozen.  This was probably the only time during the build when I was hoping for OAT in the teens.  It looks a bit dirty now, but I think it will look great when I get it back from the upholster.
   The upholster took nearly a year to complete the job, but in the end it was worth it.  Total cost in 2009 dollars was about $850.

Boost Pump and Fuel Selector
Since this plane will be equiped with a fuel injected engine, I am required to install a high pressure boost pump.  I purchased the recommended pump and installed it on the floor in front of the seat.  My dad designed and built the mount, which of course means it has a safety factor of around 11 or 12.

Fuel Tank Vent Lines
   Coming soon..

Gear Leg Stiffeners
   According to most RV pilots, the wheels and gear legs have a tendency to shimmy right around taxi speed.  In my opinion, the cause of this vibration is rooted in the fundamental fact that the kinematic friction coefficient < static friction coefficient.  In other words, an object (tire) that slides has less grip than an object that is not sliding. Why do you think ABS is so popular?
   So the following is what I think is happening:  As the tires are rolling down the taxiway, their minute toe-in or toe-out alignment is causing them to want either roll towards each other or away from each other, depending on alignment.  As the tires roll towards or away from each other, the gear legs are forced to bend in a way that they do not like. The farther the gear legs bend, the more force is exerted on the tire.  Eventually the gear legs exert so much force on the tires that the tire begins to skid on the pavement. Remember: kinematic friction coefficient < static friction coefficient.  As soon as the tire begins slipping, the gear leg unbends like a spring all the way to its natural position.  Again, this is because kinematic friction coefficient < static friction coefficient.  With the gear legs straight and happy again, the tire regains static contact with the pavement and the cycle repeats.  At taxi speed, the period of this cycle happens to occur at the natural frequency of the gear leg.  The only way to fix this problem is to change the friction coefficient of the tire, increase the mass of the system, or increase the stiffness of the gear leg.  Inflating or deflating the tire doesn’t change the friction coefficient of the tire in any meaningful way (trust the math), and therefore wont work. Balancing the tire also will not work.  You could add mass to the wheel, but if you dig up the equation describing simple harmonic motion http://en.wikipedia.org/wiki/Harmonic_oscillator you will find that it takes a lot of mass to move the natural frequency of a system.  The math behind all of this tells us that it makes most sense to increase stiffness of the gear leg.  I basically built mine per plans, except a few inches shorter.

Strobe Light Power Source
   Finding a hiding space for the strobe power source can be a bit tricky because it is a very electrically noisy component that must be located far from the instruments and near the wings.  I decided to mount it under the seatpan in the right rib bay.  I mounted it on 3/8" nylon standoffs so that it would accomodate the curvature of the seatpan.

Upper Gear Leg Fairings
   There isnt much to say about these parts.  At this point in the build a pair of handmade glass fairings can be made with one eye closed while eating a bowl of cereal.