Fuselage structure completed.

We've been away on holiday and I managed to crack a couple of ribs in my back falling off some steps whilst gardening, but nevertheless good progress made since my last blog entry.  More wiring completed, flying controls almost finished and significantly, the two halves of the fuselage have been joined together!

I've finished routing the fuselage wiring loom and pitot-static pipes to the instrument panel. This is looking forwards/upwards in the centre console.  They go behind and over the rudder pedal assembly which is really awkward, as is installing the small cable guide to the left of the central rudder bar pivot.  Anyway it's all in and ready for terminating at the panel.

I've also installed the control sticks and associated flaperon push-rods (just visible below the white horizontal tube) and the rudder and elevator cables.  I mis-rigged the control stick push-rods initially (mis-read 9 5/16" on my steel rule and set the distance as 9 5/32" instead) which meant the control sticks weren't parallel with the controls in a neutral position. Therefore  I had to strip the sticks and push-rods out and do it again - a real pain as there are spacing washers needed which I ended up super-gluing in place.

The transmit switch wiring is now in.  Not visible are the cycle handlebar grips at the top of the control sticks which also contain the Press-to-transmit (PTT) switches.  Now I can remove the reminder label! 

I've completed all of the headset wiring - this picture just shows the co-pilot's sockets including a stereo jack.  Deborah (SWMBO) doesn't find flying very rewarding, so she can independently listen to an iBook or music whist I manage the radio and get us to somewhere of interest!  It does mean I have to have a separate PS Engineering PM3000)  intercom system which is another deviation from the Vans plans.

I've also added supplementary BOSE headset connectors which allow the use of aircraft-powered ANR headsets instead of using battery packs.  All of this took well over a day to do both seats, whereas using the Van's harness, it could probably have been done in a couple of hours!  Nevertheless I don't have any of the awkward miniature Molex plugs that Vans use and I have additional capabilities.

The last bit of fuselage wiring so far was to terminate the spar pin switches.  These switches are there to warn the pilot if the wing-spar pins aren't secure and prevent the engine being started. My kit came with magnetic reed switches which are meant to be awkward to adjust. Subsequently Vans came out with an upgrade for use with miniature push-button switches (mounted just below the 2 shiny screws) so I've gone with the later system.

This shows the left wing disconnect panel complete with AOA pipe.  I've temporarily fitted the plate so I can mask around the outside ready to prime the skin beneath.  The piece of foam taped to the skin is protecting the Garmin outside-air-temperature probe which can easily be damaged but needs to be fitted now as this can only be accessed through the wing break cover plate.

Now it's finally time to do some serious structural work and join the front and rear sections of the fuselage together.  With some assistance I got the tail cone down from where it's been hanging from the ceiling for the last 20 months and positioned it onto the rolling trolley.

The forward fuselage is still on it's side as I was completing some flying control work.   With the tail cone on the trolley I can move it around single-handed to get the two parts aligned.

I took the opportunity to install the magnetometer and wiring harness into the tail cone and complete the re-worked static pipe system before the two halves were joined - much easier access than doing it lying down though the fuselage under the roll bar.  I also added a disconnect plug for all of the tail cone wiring (magnetometer and pitch trim) and also for the nav antenna so I can just plug the two parts together when the mechanical work is complete.

So on to the fuselage assembly.  Here's a view from the left side of the front and rear fuselage sections cleco'd together and ready to rivet.  Not really visible but also in place are the seat belt shoulder strap fittings either side of the roll-bar brace.

And a view from below.  Setting all of the rivets probably took about a day which includes two lower fuselage panels below the baggage bay which have the exit holes for the flaperon controls.

Main riveting complete and ready for the turtle-deck panels (around the back window) to be installed.

A view looking down gives an idea of the length of the fuselage which now takes up almost the whole depth of the garage.  There will be just enough room to get the engine installed but not the fin/rudder or propeller.

Of course something had to go slightly amiss during the joining process and it's shown here - the top skin should sit over the lower skin.  I didn't notice the error as I pulled the two halves together and it didn't help that I did all of the joining on my own.  Fortunately I spotted it before the turtle-deck panels were installed.  It only meant drilling out 10 rivets and then flexing the skins apart carefully to to get them in the right place. Unfortunately I'd made the same mistake on both left and right sides of the fuselage!

Next job is to install the turtle-deck panels and prepare the rear window.  Here the panels are in place and cleco'd with the perspex window ( a flat sheet which has to be bent to the right shape in situ).  I was very nervous doing this in case I damaged the window but so far so good.  The forward window fixing holes are then match-drilled into the roll bar and then with the window removed, the roll-bar holes are opened-up to final-size and tapped with 6-32 UNC threads for the securing screws.    The window won't finally be installed for a while - access is needed to finish the fuel tank installation and I have to complete painting the roll bar.  I want to leave the painting until the canopy installation is done as that may produce some scratches etc.

Turtle-deck lower and rear edges riveted in place.

Finally with the rear window removed and the fuselage positioned onto both lower trestles where it will live until the avionics are complete and the engine cowlings and landing gear are installed over the next few weeks. Before all of that it's inspection time again.

A bit more progress

I've done a bit more wiring (the main harness is now all installed in the fuselage) and I've also started on the flying controls.

 This is the autopilot roll servo installed at the back of the centre fuselage with wiring completed.  If the tail cone was fitted I'd have to do this lying down inside the fuselage at arms length!   I'm adding tail-cone disconnects for the magnetometer, trim motor and Nav antenna so I can just plug them all together when the two part of the structure are jointed together.

 The two connectors on the left are for the attitude/air data computer which hangs on the underside of the baggage bay floor panel.  It will also have 3 plastic pipes (pitot, static and AOA).

Here's the autopilot roll servo below the pilot's seat - we're looking down and the front of the aircraft is to the left. Note to self - fit the connecting rod bolt into the operating arm before fitting the servo next time!

Roll servo viewed looking left across the cockpit.  The troublesome bolt is now visible and wrapped in tape to keep it in place!

The two avionic cooling fans have gone in.  They only use two fixing screws and the instructions say not to over-tighten or the flanges will break.  So I made some spacers from spare brake pipe.

The rats-nest of wiring in the foot-well is growing but I won't deal with this for a while - I'm more bothered about items in the centre fuselage and rearwards so that I can finish these with easy access and get the tail cone attached.

So starting to deal with the controls now that all of the wiring is in the centre tunnel.  First job - paint then install the flap operating arm and mixer assembly. Getting the mixer to clear the wiring bundle was a real headache!

Another view of the flaperon mixer.  You can see the protective cover at the top over the wiring harness - there's just no room left for any extra wiring.   

The flap handle mounting at the rear of the control tunnel (the two lugs are for the seat belts).  Another tight squeeze so the flap handle cross-tube doesn't rub on the fuel pipe (right side) or wire harness on the left.  At least by installing the avionics wing before the controls, I won't have to disturb this or try and feed cables in with the controls attached which I think would be impossible.

The RV12 is designed to met the LSA standard with a maximum weight including fuel and passengers of just 600Kg.  So everything has to be light.  This picture to me seems to take it to the extreme.  At the top is one of the control rods that join the control column to the flaperon mixer for roll control.  It's not much thicker than a pencil!  At the bottom is one of the push-pull rods that goes rear to the flaperon operating arms.

Finally for this week a bit more wiring.  I completed the wing root connections - designed to enable the wings to be quickly removed for transport just like a glider.   Above is the right wing connector

This is the left wing connector complete with a pneumatic pipe disconnect for the AOA (angle of attack) sensor.  I've now just got to terminate the headset sockets and add a BOSE powered socket and then I can close the wing root panels.

Woodwork and wiring

A short update - no major changes visible just yet.

I decided to make some trestles as they're needed for future maintenance and also when I join the fuselage and tail-cone in a few weeks.  I'm short of bench space with the fuselage on it so now seems an opportune time.  Vans provide some height and width recommendations so I've followed their instructions.

Here are the completed trestles - just waiting for two layers of carpet to be added on top as padding to protect the fuselage.

Here the trestles are on a trolley so I can move the aircraft around on my own.  The fuselage is on it's side again for access to paint the interior.

 

I've masked off large areas as I'm only painting the areas that will be visible when the interior is fitted.   I still have to paint the roll bar and cockpit side rails where the canopy fits but am leaving that for a while as it'll get marked during the build.

 Another view of the painted interior.  The fuselage is very stable so no worries about it falling off the trestles!

Next stage is to start wiring!   As mentioned in the previous post, I'm deviating from the plans and doing my own thing with point-to point wiring and not using the Vans-supplied junction box or fuse/switch panel.  I have stripped the Vans fuselage and options harnesses to use the coloured wiring where possible - at least this way the wire functions will still correspond to the factory drawings.  I will eventually produce an accurate wiring diagram but for now am using a combination of Vans and Garmin drawings and my own ideas.

This is the Vans complete drawing for a G3X-equipped RV12.  I had it printed full size (A0) by a local print shop but it's still not really large enough to use even with a magnifying glass!.  I still need to use the laptop so I can zoom in the read wire colours or plug numbers. The big bit in the centre is the junction box that I'm discarding.

So underway.  Here is the conduit on the back of the spar box and some of the wiring is starting to go in including power to the fuel pump.

Looking down on the centre tunnel between the seats with most of the cockpit electrical wiring (lights, spar switches, canopy latch, fuel pump etc) in place although not tidied or clipped.  Also in there are pitot and static pipes and antenna cables.  I still have to add avionic wiring for the G3X EFIS and autopilot.  It's going to get extremely tight to get all of the required wires through the bulkhead bushes! 

Spaghetti starting to build up.  I will start by completing the pre-terminated lighting wires at the wing break plugs and then work inwards clipping as I go so I don't cut any of the Vans cables too short.  However, by doing this it's essential to make sure all required wires are in place first. I'm adding a few extras such as power for ANR headsets (and additional BOSE connectors) plus audio to a remote GoPro camera so it will record the intercom and radio as well as the image.

Here is the left wing-root waiting for the wiring to be terminated and the plug mounted.  I'm adding the optional AOA sensor so there's an additional pipe to connect to the wing as well.

As avionics has always been my day job, I'm using standard wiring techniques including sleeving on exposed wiring to prevent chafing.  It also tidies things up and makes it look better!

More of the same next time plus hopefully some of the flying controls.

Instrument panels (more than one!) plus much more.

I've had a busy few weeks making progress on the fuselage, with installation of systems underway and getting ready to start wiring.  At this stage I should be joining the tail cone to the cockpit but that will restrict access so I'm working away from the plan.  I'm also changing the design a bit by making a one-piece instrument panel so I can accommodate the dual-screen Garmin G3X Touch display system, GMC307 autopilot controller, Garmin GNC255A Nav/Com radio and the UK-mandated standby airspeed indicator, altimeter and compass.

Firstly, we had a delivery!  The firewall-forward kit is here together with  all of the remaining parts to complete the kit (other than those that I've just scrapped as you'll read below!).

One crate weighing about 180Kg.  Fortunately the lorry that delivered it had a tail-lift and the driver had a pallet truck to manoeuvre the box.  It's got everything inside including an individually-crated Rotax 912ULS engine, propeller, battery and loads of assorted pipes, exhaust etc.   Need to up my insurance cover now - the engine is worth more than the aircraft!  

So, continuing with the rudder pedals and brakes that I'd started to assemble on the bench.

I completed drilling the rudder pedal and brake assembly on the bench.  The brake pedal has to be clamped vertically so you can see my digital protractor showing 89.95 degrees - close enough!

Prior to installing the pedal assembly, the forward firewall needs to be sealed to keep any nasty smells and gasses out of the cockpit.  Here the edges in the foot-wells are masked ready for the high-temperature sealant.   The grille on the left is the cockpit heater entry.

This view shows the pedal assembly installed onto the firewall shelf and the new braided brake hoses from TS Flightlines fitted (although not yet properly clamped in place).  In the centre with the red caps is the new parking brake valve.  I have to make the next sections of pipe that go to the main undercarriage from rigid plastic pipe - I'm told it's a bit of a pain to do..

So on with installation of fuel components.  

This is the fuel valve in the centre floor just in front of the seats.  It allows me to shut off the fuel between the tank and the engine.    It's also plumbed - I have the make up all of the pipes and flare the ends for the fittings.  The smaller pipe is the fuel return line which sends excess fuel back from the engine to the fuel tank.

This is the Red Cube fuel flow transducer - it measures fuel flow rate (litres per hour) so the Garmin EFIS can calculate total fuel used and remaining endurance.  On the right is the parking brake valve.

Here is the fuel pump installed under the rear floor and with the pipes attached.  Getting these pipes properly lined up and clipped was a bit of a challenge - especially installing the return line union at the top of the picture as you can't really get to the back of the fitting in the spar box to tighten the nut!  The fuel tank sits on the floor to the right of the pump.

Finally at the bottom of the engine firewall is the gascolator - a fuel filter and water drain. I'm also adding an additional drain valve directly below the fuel tank using a design created by my inspector Jerry for his RV12 and which has proved very popular. 

The black structure on the left of the picture is the engine oil tank bracket and battery box. The final black bracket in the centre is for mounting the GPS antenna under the fibreglass cowling.

Before moving on to the avionics and wiring I decided to put the seats together.  I'd prepared the parts months ago so it was just a matter of riveting all of the parts once they'd been painted.  I have all of the factory interior trim and cushions stored in a spare bedroom!

Now the avionics shelf and canopy hinge and strut supports get installed.  Just a matter of loads of riveting.

Here's the avionics shelf installed and ready for the top cover to go on.The heavy angle bracket supports the canopy gas strut.  The canopy hinge is where the beefed-up doubler is fitted just behind the firewall.

More anchor nuts - this time on the sections that rivet to the top cover and to which the top of the instrument panel will be secured. 

Here's the top cover in place ready for the instrument panel strips to be riveted.  This panel is normally removable for access to the avionics but required sealing along the front edge to prevent water getting in.  Must remember to put release agent (wax) on one surface so it'll come off when the sealant dries!

Now I'm starting on the avionics and electrical system wiring as this has to go in before the cockpit flying controls.  I need a new instrument panel to locate the main electrical components so that's the first thing to work on.

The panel is made from a single piece of 0.063" aluminium.  I used the 3-piece factory parts to create a template which gave me the outline and fixing hole locations.  After making the large apertures using a powered nibbling tool, it's down to muscle power with hours of careful filing.

Here's the finished product in place for a first trial fit.  Looks good at this point. Knowledgeable RV12 people may notice the lack of a throttle mounting plate on the panel. I've decided to do a split arrangement so the instrument panel can be removed without disconnecting and removing all of the engine controls!

I just had to put the Garmin screens, autopilot controller and ignition/power switch unit in!   I'm really looking forward to flying this - it's so much more modern than anything I've flown so far.

Of course all good things come to an end!  I had to match-drill the instrument panel centre supports which also support the radio tray back into the new instrument panel, and when I did it, I had the top cover fitted (not shown in the picture) and then drilled back through the supports using my right-angle drill. However, doing this blind and finding the holes using a mirror was a big mistake and two holes ended up out of position.   This also meant the supports were scrap and I need to order replacements from the factory. Time to walk away and think about it for a while!

So after a few days away doing other things, it's back to the panel and attempt number two. Here's the main section cut. I've made some changes based on my first experience.  I'm altering the switch layout to accommodate a separate fuel-pump switch (not part of the basic kit) and I'm also not using the master switch assembly.  I think it will look neater if the ignition components just mount individually though the main panel.

I'm still awaiting new support struts from the factory and will take a different approach in drilling them to prevent the previous mistake.

Here I've marked out the six switch positions and chain-drilled the holes.  The waste is easily removed with a sharp chisel and then back to filing!

The nearly-finished article including the new ignition switch cut-outs on the left side but still waiting for circuit breaker holes on the right.  I'm making quite a lot of extra work for myself - the factory wiring won't work  and the radio rack structure all has to be altered, but I think the overall effect will be worth the effort. I had no choice for at least some of the changes as I have to fit the extra standby instruments and there's no space normally available.

This shows the original ignition panel which normally sits behind the panel though a large square cut-out.  I'll still have the control unit itself screwed through the facia but it won't have it's own face-plate.  I'm hoping to find a company that will silk-screen-print all of he required legends on the finished panel which should provide a professional finish.

Moving on in the next few weeks should be all cockpit wiring, flying control rods, pulleys and cables and then join the front and back together!