Up on the gear [10.5 hours]

I agonized over how best to raise the airframe to install the gear legs. I gathered some family muscle to lift it up onto a workbench, but aborted the attempt after it became clear we couldn’t do the lift with enough control.

I borrowed a 500kg lift table, removed the handle, and made up a frame that provided support under both the main and rear spar. I wanted a backup in case there were any problems with the lift table, so I crudely extended the forks on the tractor, added a bit of padding, and held these an inch below the airframe, as shown. As it turns out, the table did fine and the tractor was not required.

I fitted the left main gear leg and wheel, then had to cut the old dolly apart (committed at this point!) to get it out of the way and fit the right main gear leg and wheel. After fitting the nose gear, I let the table down and the fuselage settled in a nose high position (because of the missing engine weight). It looks awkward like this, but it’s still quite a milestone to get it up onto the gear.

  • f43a
    Raised by lift table, getting backup tractor forks in position
  • f43b
    Raised by lift table, tractor forks for safety
  • f43c
    Raised by lift table, tractor forks for safety
  • f43d
    Cutting away the old dolly
  • f43e
    Left main gear on, ready to do the right
  • f43f
    Left main gear on
  • f43g
    Both mains and nose gear on
  • f43h
    Back down, on the gear, nose high with no engine weight

Firewall insulation [7.5 hours]

Now that the upper forward fuselage assembly is riveted on, I can go ahead with the firewall insulation, using the Titanium foil and 1/8″ Fiberfrax I had previously prepared.

In order to prevent the Titanium from puckering, I used 1/8″ stainless steel spacers (available from McMaster Carr) for all #8, #10, 1/4″ and 5/16″ holes, and stainless steel washers for larger sizes. I used RTV to hold the spacers “in place”, a few swizzles of Fire Barrier 2000+ to hold the Fiberfrax in place, and then put on the Titanium. I used machine screws to retain the Titanium in place, these will later be replaced by whatever their respective position calls for. There’s a few pulled rivets across the bottom, and for most of the pass-thru’s I had left one rivet position open so that retaining rivets can be used here as well. The rivets I used are stainless steel, and have a closed end cap, so they should seal up quite well.

I installed the A/C pass-throughs and steel AN fittings for the duplex fuel system, and riveted on the oil cooler mount. I previously made up a Titanium insert for the center recess. I subtracted 1/8″ all around from the recess dimensions, and made the insert accordingly. The thing’s a work of art, but it turns out I should have allowed more wiggle room so I’m going to toss it and make up another one.

I went on a bit of a campaign mounting various items on the firewall, to get them off the shelf and out of the way. Finally, the engine mount went on and that’s another large item no longer on the floor.

I moved the paint booth out and tossed it in the farm shed. I don’t really have much use for it in the coming months, and moving it out clears up a lot of room in the workshop. At the very least it needs re-lining, it’s more like a dark room these days. It might get torn down, I think its usefulness is over after four years of dedicated service – an entire slow-build RV-10 got primed in that little paint booth!

  • f41a
    1/8" spacers RTV'd to firewall
  • f41b
    All spacers and washers RTV'd to firewall
  • f41c
    Trial fit of Titanium, taped together in correct alignment
  • f41d
    1/8" Fiberfrax in position
  • f41e
    Titanium in place, oil cooler mount riveted on
  • f41f
    Fuel fittings, heater box holes
  • f41i
    Engine mount on
  • f41g
    Moving paint booth out
  • f41h
    Moving paint booth into farm shed

Upper forward fuselage [85.5 hours]

With all the avionics in hand I decided how everything needed to fit behind the panel. This included not only the avionics, but also the SDSEFI system. Cable routing is another consideration – D connectors, and in some cases a “straight” section of cable running into the D connector – have to be accounted for. Suffice to say, the final layout turned out to be different than the layout I had previously worked out simply based on box dimensions.

I made up brackets for securing the rear of the IFD GPS chassis, and added stiffeners to the sub-panel where required in accordance with Van’s guidelines. I had to mount one item – the secondary system voltage regulator – on the back of the sub-panel. To make it easily removable I added nutplates to the mounting flanges. These will be easy enough to drill off and mount on another regulator if/when it must be replaced. I also drilled two fan mounting holes in the top skin, using a circle cutter in the drill press set to 250 rpm.

Once I was happy with all of the brackets and stiffeners, I primed them, riveted together the forward front fuse subassembly – including all of the brackets and stiffeners – and painted the exposed interior and top shelf area in a flat black polyurethane.

While the forward fuse was still open, I trimmed and fitted the Aerosport interior side panels, installed nutplates for these side panels, installed the NACA vents, and installed the rudder panels for the last time. I also completed all of the tunnel work, permanently installing the brake lines, fuel lines, fuel filter and wiring for the fuel pumps.

Finally the time came to rivet the subassembly onto the fuselage. One advantage of the Control Approach rudder pedals is that access is quite good through that area, once you’re upside down with your head under the panel. The riveting went fine and I was also able to complete the firewall riveting, including the brackets and spacers I had previously made up for the Skybolts.

Next job is to fit the firewall insulation and engine mount.

  • f40a
    Drilling and cutouts in Aerosport 310 panel backplate
  • f40b
    Making brackets for AFS ACM module
  • f40c
    Making brackets for rear of GPS tray mount
  • f40d
    Fitting brackets for rear GPS tray support
  • f40e
    Fitting brackets for rear GPS tray support
  • f40f
    Fitting brackets for rear GPS tray support
  • f40g
    Fitting brackets for rear GPS tray support
  • f40h
    Remote audio module fits in same bracket
  • f40i
    Figuring out nutplate positions for Adel clamps
  • f40j
    Drilling nutplate holes
  • f40k
    Modified B&C regulator for rear sub-panel mount
  • f40l
    Modified B&C regulator for rear sub-panel mount
  • f40m
    Trimming Aerosport side inserts
  • f40n
    Priming extra sub-panel brackets and parts
  • f40o
    Cutting Fan holes in front forward subassembly skin
  • f40p
    Riveting brackets to forward front panel assembly
  • f40q
    Fitting skin to forward front subassembly
  • f40r
    Upper forward fuse subassembly riveted together
  • f40s
    Upper forward fuse subassembly riveted together
  • f40t
    Ready to paint flat black on upper forward fuse subassembly
  • f40u
    Painted upper forward fuse subassembly
  • f40v
    Painted upper forward fuse subassembly
  • f40w
    Fitting Aerosport side panels, NACA vent proseal'd in
  • f40x
    Bucking rivets the hard way
  • f40y
    Upper forward fuse riveting complete!
  • f40z
    Upper forward fuse riveting complete!

Cabin top on – for good [11.5 hours]

I’ve fitted the cabin top – for good. It’s riveted on and retained with structural epoxy, so it isn’t coming off again. The RV-10 is often described as the aircraft kit that is 90% metal, and 80% composites. The cabin top goes on and off many times before it is “right”. I finally decided there was no reason for it to come off again, so … on it went. This time I scuffed the door channels and slathered on some flox, dropped the cabin top in place, did up all of the bolts along the door channel and installed rivets along each rear side of the cabin top. Now I have to fill the vertical parts of the door channels with structural epoxy, fit those bolts, and then finish the inside of the door channels with micro, fill primer, then prime and paint to match everything up with the already-painted cabin top interior.

I also primed, assembled and painted the tunnel cover pieces I’ve had laying around for a few months. These are cut and modified because of the control approach rudder pedals, which require slots and doublers in the front most part of the tunnel cover. The spray booth has just about outlived its usefulness, so I’m going to move it out of the workshop to free up some room.

  • f38k
    Tunnel covers primed
  • f38j
    Front most tunnel cover section, slots for Control Approach rudder pedals
  • f38i
    Tunnel cover primed
  • f38g
    Overhead ready for final installation
  • f38f
    Scuffed door channels before final overhead fitment
  • f38e
    Overhead riveted in place
  • f38a
    Cabin top riveted on
  • f38d
    Front pillars in place for good
  • f38c
    Conduits from overhead will fit inside Aerosport Cabin inserts
  • f38b
    Fitting cabin top

Firewall insulation [31.0 hours]

I’ve been working on the firewall insulation. There’s a lot of material on VAF about this, I won’t repeat it here. Suffice to say I’m using an insulation material called Fiberfrax, 1/8″ thick, on the outside of the firewall. In order to hold it in place, a thin metal foil layer is required. I’m using 0.008″ thick Titanium for this layer (I previously bought some 0.002″ Stainless Steel foil but decided I couldn’t work it without having it crinkle up and/or tear. Impossible to drill a hole through it). The main purpose of firewall insulation is to give me some time to get the aircraft on the ground in some sort of controlled manner, in the highly unlikely event of an engine fire. A secondary purpose is to minimise the amount of heat that can be transferred into the RV-10 tunnel.

I found the best tool to cut the Titanium foil was an ordinary pair of scissors. Drilling small holes wasn’t a problem, but enlarging them with drill bits is not possible. I used a series of reamers for the smaller holes, the angled end of the flutes works well. To drill a #12 hole, for instance, I would first drill a #42 hole, then #39, #35 using drill bits, then #30, #19 and finally #12 reamers. The back of the foil must be supported of course.

For larger holes, a step drill works, but to finish the hole or enlarge anything beyond around 9/16″, I used a 1/2″ round sanding attachment in a die grinder. These wear out quickly, I went through around twenty of them. Doing these large holes with the die grinder worked well, as long as the foil was supported right up against the stainless steel firewall.

In an ideal world, all of the firewall nutplates and pass-through positions would be known when the firewall was laying on a bench, before ever being attached to the fuselage. That doesn’t happen, so I had to find a way of accurately drilling holes through the foil for all of the nutplates etc. To do this, I 3D printed a lot of disposable drill guides. For any purpose, I designed a drill guide, printed it, and used it to accurately drill a #42 hole through the center of whatever I needed to. In this way, I worked around the firewall and made all of the holes required in the Titanium foil. I used #6 screws through the AN3 nutplates to hold the foil in place while I worked on it, and clecos where appropriate.

With the foil prepared, I cut the Fiberfrax to shape, sandwiched it between the foil and firewall, and then worked my way around all of the holes, cutting the Fiberfrax as necessary with a sharp modelling knife. For the engine mount points, I completely removed the foil and ‘frax. All of the gaps will be filled in later with Fire Barrier 2000+.

I then set the Fiberfrax and foil aside. I can’t attach it permanently until the upper forward fuselage assembly is riveted in place. In fact, all I seem to have done for months now is to prepare parts, and set them aside.

One of the downsides of adding firewall insulation like this is that it makes future firewall modifications difficult. It is possible to drill through the foil and firewall, but deburring is a problem. I tried to anticipate everything I could, and for pass-throughs I put in more than I needed, it’s easy enough to plug up unused pass-throughs. I also made a separately mounted plate that attaches to the right side of the firewall, for mounting electrical components on. At some future time, if the electrical requirements change, I can simply make up a new mounting plate for them, rather than rely on firewall mounted nutplates for each individual component.

  • f37a
    3D printing a drill guide
  • f37b
    Drilling holes in Titanium foil
  • f37c
    Drill guide to go through AN3 nutplate
  • f37d
    Drilling center hole through Titanium, from the rear
  • f37e
    Drilling holes for oil cooler mount
  • f37f
    Marking out upper Titanium foil sheet
  • f37g
    Cutting upper Titanium foil sheet
  • f37h
    Holes cut out in top Titanium sheet
  • f37i
    Titanium foil insert for center section
  • f37j
    Titanium foil insert for center section
  • f37k
    All the drill guides used for Titanium foil
  • f37l
    All holes and cutouts done, except for center
  • f37m
    Engine mount cutout
  • f37n
    Engine mount cutout
  • f37o
    All holes and cutouts done, except for center
  • f37p
    Fiberfrax stored for later use
  • f37q
    Pass-thru's riveted on

Firewall, engine, Skybolts [37.5 hours]

I’ve started work on the firewall penetrations. Since I’m using SDS/EFI there is a need for more wiring through the firewall than is the case for a conventional Lycoming installation. There is also a return fuel line associated with the duplex fuel system, and a fuel regulator. The location of all the parts and pass-throughs needs to be determined, so that I can drill the necessary holes. In accordance with current “best practice” for firewall insulation (in case of an engine compartment fire), I’m installing a Fiberfrax insulation layer on the engine side of the firewall. This requires a thin metal retaining layer on the front of the Fiberfrax. I bought some 0.002″ stainless steel foil for this purpose, but decided there was no way I could work with it without winding up with a crinkly mess, so I have switched to some 0.008″ Titanium.

I temporarily lifted the (Barrett) engine into position to ensure there’s plenty of room around the pass-through positions. I installed doublers for the AntiSplat air/oil separator and the A/C line pass-throughs, as well as various nutplates that are in addition to the plans.

Speaking of the engine, apart from desiccant plugs I’ve been using a home made “conditioner” to help preserve the engine until its first start. I placed about 2kg of (orange) silica gel in a sealed plastic cake container with an aquarium pump. The outlet of the aquarium pump goes through a respirator filter (to prevent any silica dust from entering the crank case), and then into the oil filler hole. A tube from the breather outlet goes into a glass bottle, and a separate tube from the bottle for return air into the plastic container. A humidity sensor in the bottle shows that the crankcase is being maintained at a humidity level of less than 10%, whereas the outside air humidity is often above 50%.

I also worked on the cowling mounts at this time. I’m going to use the Van’s hinge method for the firewall sides, and between the two cowl halves, but have decided to use Skybolts for the upper cowl firewall mount. To that end, I bought a kit of parts from Skybolt. Included in the kit are these nifty looking interlocking flanges, but when I started to work out how to lay them out, I found that I would have to adjust the spacing between skybolts in a fairly arbitrary way to have rivet holes in the flange overlaps occur in sensible places with adequate edge spacing. I really didn’t like the resulting uneven spacing, so I decided to make my own Skybolt flange mounts.

I used two sections of 0.032″ Alclad, overlapped in the middle (top). Marked out, drilled, cut, and then match drilled into place from the firewall edge with the top skin in place. I made a small overlap between the two halves, and dimpled all of the #40 holes to match the firewall. I also added a 0.02″ Alclad spacer to the assembly, same as would be used with the hinges, to allow for some filler on the cowl edge. With these cowl brackets complete, I put them aside since they can’t be riveted on until the upper front fuselage assembly is ready to rivet on. The hinges on each side, and spacers, were made in accordance with the standard plans and riveted in place. I haven’t done anything with the bottom hinges, since these are not used for the Showplanes cowl. I’ll most likely add a Skybolt or screw/nutplate on each bottom side but can’t really do that until I’ve fitted the cowl.

  • f33a
    Figuring out firewall pass-through locations
  • f33b
    Figuring out firewall pass-through locations
  • f33c
    Figuring out firewall pass-through locations
  • f33d
    Figuring out firewall pass-through locations
  • f33f
  • f33g
    Engine environment on right, outside environment on left
  • f34a
    Marking out second Skybolt bracket (first above)
  • f34b
    Cutting diagonals - carefully!
  • f34c
    Cutting diagonals - carefully!
  • f34d
    After initial drilling and cuts
  • f34e
    Overlap formed with hand seamer
  • f34f
    Match drilling to fuselage, with 0.02" spacer
  • f34g
    Finished skybolt brackets for upper cowl, side hinges riveted in place.
  • lola1
    RIP old friend

Clearcoat done [8.0 hours]

After a lot of preparation, I sprayed the clearcoat onto the overhead console. I’m not much of a painter so I’ve got one run to scrape out and the whole thing will need a cut and polish, but it turned out fairly well and I got the effect I was looking for in terms of the transition from the light grey overhead colour into the carbon fibre console. More importantly, the overhead console is now UV protected with the Durepox clearcoat product I used.

I’ve put the overhead aside for now, time for a break from fibreglass and painting so I’m going to get back to the firewall and work towards getting the fuselage up onto the gear.

  • f32a
    Set up on a nice day
  • f32b
    Spraying clearcoat
  • f32c
    Spraying clearcoat
  • f32d
    Clearcoat done, before cut and polish
  • f32e
    Clearcoat done, before cut and polish

Cabin Top Blues [45.0 hours]

My long battle with the Cabin Top is coming to a close, at least for the interior. Various choices made the task harder than it should be, but the end result is now in sight, and I’m happy with how it’s turning out.

Including A/C in this aircraft meant an overhead console would be needed, so I bought the Aerosport Products carbon fiber overhead console. I wanted wiring conduits up each front pillar to make wiring easier, so that brought about a whole load of work to glass these in and finish the pillars appropriately. I’m installing Visors so that requires mounting points, but Van’s have taken the position that holes should not be drilled in the front pillars because the holes have an unknown impact on the rollover protection, so I made up some metal inserts with Nyloc nutplates and glassed them in.

I bought the Aerosport cabin headliner kit, but the headliners were compromised during shipment. I could have repaired the problems, but overall I decided against using a headliner, which meant that I had to finish the entire cabin top interior. This amounts to a lot of work, because the Cabin Top as it comes from Van’s is quite rough, and there are a lot of complex shapes and curves involved, especially after glue-ing in the overhead console. The headliner would not have helped much either, the hardest parts are outside of the area that a headliner would encompass.

I decided to keep the Carbon Fiber look for the overhead console, this added yet another layer of complexity because it had to be masked off while the rest of the interior was painted, and masking off the line between the interior paint and the overhead console is difficult because of the afore-mentioned complex shapes.

Previous choices had an impact as well. Some time ago I chose to use the McMaster Carr door seal, so as described in previous posts I used a length of seal as a mould and built up the door frame to a constant 1/4″ width all the way around. When you do this, there is a “jag” on the inside of the seal which winds up making a nice groove on the interior side of the door edge. This is a good thing, because when you put the “real” seal in place, the seal jag slots into this groove and helps to hold it in place. While spraying fill primer, I didn’t want this groove to fill with with primer and disappear, so I had to tape off to just beyond the small groove around all the door frames. I removed this tape before spraying the primer and topcoat.

If you’re building an RV-10 and want to minimise the work on the cabin top interior, then don’t do any of the things I’ve done. Otherwise, here is the entire process I’ve used:

  1. Fit the cabin top etc., and create the door gap for the McMaster seal (see previous post)
  2. Fit the overhead console, and glue it in. I used Lord adhesive for this (see previous post).
  3. Fit the wiring conduits to the front struts, and glass them in with 3 layers of glass. See previous post for details on how I used a Nylon 3D printed part to transition into the overhead. I used straight epoxy, blackened with die, to seal the Nylon transition pieces into the overhead. The same technique was used to seal around the (black Aerosport) door strut brackets.
  4. Make metal inserts with Nyloc nutplates for the visors. Position these so that the visors just miss the overhead console when (unextended and) pushed to the front. Glass these inserts in at the same time as step (3) above. Triple check their position with the real visors before doing so!
  5. Apply filler (epoxy + micro-balloons + cabosil) to the front pillars to create the desired shape around the conduits, and transition into the visor mount points which must be kept flat.
  6. I didn’t like the amount of material left on the cabin top roof after the front seat belt mounting bolts were countersunk, so I added three layers of glass around these points to create a slight “bulge”. I added filler around this “bulge” to transition smoothly back into the cabin top.
  7. Apply filler everywhere else around the interior, and to transition from the overhead console back into the interior. This took several iterations to get right, so fill, sand, fill, sand, fill, sand ….
  8. I cleaned everything off with wax and grease remover, and scuffed the overhead console to prepare it for later clear coat, with a 600 grit wet sand. Then I cleaned everything off again and taped up the overhead, and fussed over the edge that I was going to tape to. This edge I made about 1/4″ back from the corner of the overhead – it’s really impossible to tape a straight line on the corner when you have to go around bends in three dimensions.
  9. After cleaning off again, I applied a thin glaze of straight epoxy over the “flat” parts of the cabin top, i.e. the parts where I could use a squeegee. This was to fill pin holes. Around the curves and steps, I didn’t do anything in particular for pin holes at this point.
  10. I rolled on a coat of Wattyl UC-230 primer-surfacer, let it dry, and sanded it back. I wouldn’t bother with this step again, I was still left with a zillion pin holes and it’s much more effective to just spray it on.
  11. Without bothering about pin holes, I sprayed on a second coat of UC-230, using a cheap gun I bought for priming that had a 1.8mm nozzle. Once this dried, I sanded it back. The result was a zillion pin holes, a lot of small low spots where further sand/surfacer operations were required to render the interior flat, and a few larger low spots that required a bit more filling.
  12. I filled the few “larger” low spots as required, and applied Ever-coat 440 express pinhole filler. Be careful if you use this product, it is highly toxic. After this, another coat of UC-230 and sand it back.
  13. I repeated the process – spray on UC-230, sand it back, fill pinholes – about another three times. Each time I probably sanded 80% of the material off – but never back to the previous layer – and got down to the point where (a) I couldn’t find any more pinholes, and (b) when I sanded it back, there were no “low spots” left. It’s easy to see the low spots, they remain shiny in reflected light while the material you’re sanding doesn’t.
  14. Once I was happy with all the surfacing, I sanded the surfacer down to the level of the tape along the transition line to the carbon fiber console, removed all the tape, and then carefully sanded the edge down further, leaving a very slight rise where the surfacer began (180 grit for this sanding). I used a sharp knife to scrape away surfacer in a few tiny places where it had crept under the tape. I removed the electrical tape around the door surrounds (to stop surfacer filling up the groove for the seal jag). Then I cleaned everything up with wax and grease remover, and finally with alcohol.
  15. I re-taped the centre console, putting down a careful line with 3M vinyl tape, just “inside” the edge of the UC-230. I fussed over this taping a lot, because the next step – polyurethane primer – is much thinner paint and will creep under a bad taping job. Moreover, it will stick to just about anything and be impossible to get off. I left the door surrounds un-taped.
  16. I sprayed PPG polyurethane primer, two coats. One in the evening, one the following morning. Drying time is 4 hours. It was a perfect day outside, so I decided to spray the top coat in the afternoon. For this I used my better quality spray gun, with a 1.2mm nozzle.
  17. I sprayed two coats of PPG polyurethane topcoat, 1.5 hours apart. The 1.5 hours is just to allow the first coat to flash off. After each of the PPG primer operations and each topcoat, I rushed the cabin top back inside the garage (which is closed up) and threw a drop cloth over the whole thing to try and reduce dust, since I don’t have booth that I could fit the cabin top in.
  18. Drying time for the topcoat is 12 hours, full cure in a week. Seven hours after the second coat, I carefully pulled up the vinyl tape. A sharp knife and tweezers helps, and it’s important to avoid dropping any “shards” of paint from the vinyl tape (which it doesn’t adhere to) back onto the topcoat – it’ll stick.
  19. After the topcoat had cured overnight, I removed the rest of the masking on the overhead.

Unavoidably, a few small bugs landed on the topcoat and suffered a cruel death. I waited two days so that the topcoat had hardened up, and used a very sharp/pointy knife to remove the remains. I think I did this in 4 places, fortunately they were all very tiny bugs. These, and a few dust spots, will clean up OK when I cut and polish the topcoat. I’m not going to do this until after the topcoat has fully cured.

The next job is to spray clear-coat on the carbon fiber. I’m going to tape off the grey paint along the transition line, protect the rest of the interior with plastic etc., and spray the clear. I’m using a marine product called Durepox for this. I haven’t done it yet, so I’ll update this post once it is done. I did a little test piece and the chemistry between this and the PPG polyurethane seemed OK. I do expect to run into some pinholes in the carbon fiber, I can see them under a magnifier, so I’ll probably have to use a small brush to fill them, sand back, and do several coats of the clear before it is good enough to finish with 2000 grit wet and a buffing polish.

Once the clear is done, I’ll cut and polish the grey topcoat, glue the windows in with Lord adhesive, and the cabin top will finally be ready to fit to the fuselage for good. To finish the interior window transition, I plan to cut a rubber seal in half and cement it in place, as described in a Van’s Air Force post some time ago.

Of course, once the cabin top is on, I get to do a lot of this all over again, filling in around the lower door surrounds, filling and joining everything up with the existing finished paintwork, in theory so that it is not possible to see where the join is.

  • f31b
    3 layers of glass over conduit
  • f31c
    3 layers of glass over conduit
  • f31a
    Slathering on micro to shape front right door pillar
  • f31d
    Front door pillar after sanding
  • f31e
    Both front door pillars shaped, rear section filler sanded
  • f31f
    Visor support, and lots of pinholes
  • f31g
  • f31h
    Cleaning up after final primer/surfacer coat
  • f31i
    Surfacing finished
  • f31j
    Taped up again, prepared for primer and topcoat
  • f31k
    Spraying on first layer of primer
  • f31l
    Spraying on second layer of primer
  • f31m
    First topcoat
  • f31n
    First topcoat
  • f31o
    Second topcoat
  • f31p
    After topcoat cured
  • f31q
    After topcoat cured
  • f31r
    After topcoat cured
  • f31s
    Visor mounting points, and a bit of MC seal in place
  • f31t
    The hardest part to deal with
  • f31u
    MC seal fits under aerosport door strut bracket
  • f31v
    MC seal fits under aerosport door strut bracket
  • f31w
    Detail of groove where MC seal jag sits.
  • f31x
    Conduit, glass, micro, surfacer, primer, topcoat
  • f31z
    Ready for attachment to fuselage

Lots of odd jobs and painting [135.5 hours]

I’ve continued with various cabin and door jobs over the past month. Mounted the door struts, and was quite surprised when the doors “worked” properly. Open the door, let it go, and the door goes up by itself. I filled over the door hinge gap covers with micro, and sanded it back to shape (no photo, but it worked out well). I also glued the Aerosport overhead on permanently, using Lord adhesive. Started doing some filling work, but then elected to put it aside for a while and catch up with fuselage work – that was the work I put aside a few months ago in order to use the last of the warmer weather before winter on the cabin top, doors and windows.

I drilled the fuselage for the engine mount, to get this out of the way before painting the interior. It is apparently quite normal for the holes in the firewall to NOT line up properly with the engine mount. I didn’t pay enough attention to this, and decided to simply follow the Van’s instructions and drill one of the top holes to size (3/8″). This turned out to be a mistake, because it established an arbitrary fixed point for that corner of the engine mount and what I SHOULD have done was to establish where the engine mount had to go with respect to ALL of the pilot holes in order to (a) take out all the pilot holes, and (b) keep the mount exactly centred. Why (b)? Because on the end of the engine on that mount there will be a hole in the cowling, and a spinner that is supposed to line up with that hole.

I should have “worked” that top holeĀ  to move the centre of the 3/8″ bolt hole about one mm toward the middle, but I didn’t. I had to stretch the mount a bit with a clamp (not much, just a bit) in order to fully cover the opposite hole. The bottom middle holes were right on the edge of the 3/8″ guide on the engine mount, so much so that I could drill a #30 hole in the centre point and not actually break into the pilot hole. I was a bit concerned about how to drill these holes without having the off-centre pilot holes “pull” the drill away from where it needed to go and start scraping material off the engine mount tubing.

To resolve this, I 3D printed a bunch of drill guides. They were just cylinders with a 3/8″ outside diameter, and a #30 hole through the middle. Using plenty of cutting fluid, I drilled #30 holes in the places where I could, and “pinned” the mount in place using the shank of long #30 drill bits. In the places that couldn’t be pinned because the pilot hole already overlapped the centre, I used “other” 3D printed drill guides of various size internal holes, and stepped up the drill size in successive operations before consuming the pilot hole. The final step was to use a 3/8″ reamer to final drill the hole, and then put the 3/8″ engine mount bolt, washer and nut in place.

By the time I got to the worst two holes – which had #30 drill bits holding the mount in location, the other bolts around the mount held it in place so well that I simply ran through the same series of drill guides, stepping up the drill sizes. The mount simply could not move, so the fact that I was breaking through the very off centre pilot hole didn’t matter at all. I was able to consume those (badly off centre) pilot holes without dragging the drills off centre, again finally finishing up with the 3/8″ reamer.

At the end I had a handful of wrecked 3D printed drill guides, but they had done the job!

I found that I had installed the incorrect sized nutplates on the Antenna inspection covers, #8 rather than #6. It was a nuisance but fairly easy to drill them all out and replace them with the correct part.

Then it was on to painting. I primed and painted all the detachable interior panels, primed assembled and painted the rear seat frames, plus the remaining control rods, rod ends and some other miscellaneous bits. After that I prepared the fuselage and painted the internal floors and baggage area. Most of these areas will be covered by an Aerosport carpet set.

Once that cures, I’ll be able to go back and mount the seat rails, rudder pedals, brake lines, fuel valve and lines, and control system so quite a lot of parts I have lying around here will go into the airframe for good.

  • f30a
    Drilling cabin top for the door strut bracket
  • f30b
    Drilling out incorrect #8 nutplates
  • f30c
    Incorrect #8 nutplates removed
  • f30d
    Drilling strut bracket into door
  • f30e
    Door strut brackets fitted
  • f30f
    Door strut brackets fitted
  • f30g
    Filling over the hinge gaps and strut bracket rivets
  • f30h
    Filling over the hinge gaps and strut bracket rivets
  • f30i
    Ready to glue on the overhead with Lord adhesive
  • f30j
    Lord adhesive applied, overhead clamped/weighted in place
  • f30k
    Starting to do a bit of filling
  • f30l
    3D printing disposable drill guides
  • f30m
    Using #30 drills in guides to locate engine mount
  • f30n
    Stretching engine mount just a little
  • f30o
    Engine mount drill guides did their job
  • f30p
    Engine mount in place
  • f30q
    Backing plate to fill in rudder cable hole
  • f30s
    Filling rudder cable hole with micro
  • f30t
    Priming various internal panels
  • f30u
    Topcoat on various internal panels
  • f30v
    Priming rear seat frames and some control bits
  • f30w
    Riveting seat frames
  • f30x
    Helping paint to dry during a cold Tassie winter
  • f30y
    Top coat on seat frames
  • f30za
    Ready to paint interior floors, sides
  • f30zb
    Painting interior baggage area
  • f30zc
    Interior after painting
  • f30zd
    Compressor outdoors, cheer squad in the background


Windows, Conduits, overhead etc. [63.0 hours]

I’ve continued to chip away at the never ending cabin top work. This is clearly the character building part of the RV-10 build. It’s hard to separate activities because the doors, cabin top, windows, etc. are all interdependent. There’s a notorious flat spot on the pillars between the doors and rear windows in the cabin moulding, for instance, which has to be built up to match the door. The front side of the window also has to be spaced out so there isn’t a sudden transition between the door, pillar and window. Can’t do this until the door is fully fitted though. The inside surface where the window is raised will need to be sanded back, so it isn’t different than the rest of the window interior. All of this could have been avoided if the cabin top moulding was fixed up, but Van’s won’t do this, hence the character building.

I trimmed all the windows down to size, using the last of the warm days so I didn’t risk cracking anything by trying to work it in cold weather. I used a dremel tool with a Permagrit wheel for all of the rough trimming, followed by a belt sander with 60, 80, 120 grit belts. When the windows were all trimmed to size I ran around the edge with a 240 grit belt just to be paranoid about removing any scratches. Cutting the windows causes sharp material to fly everywhere, like shrapnel, and it clings to everything. Glad I was able to do all this work outside.

I wanted to run electrical conduits up the front window pillars, but the problem is how to transition them into the Aerosport overhead. I didn’t want to build a front assembly that jutted out, restricting the view forward and upwards from the cockpit. So I 3D printed transition pieces in Nylon that go from the 16mm conduit into a fairly flat channel, and some corresponding channel pieces which when laid together continue the Nylon wiring channel back to the point of accessibility near the forward edge of the front overhead panel. Cut some slits in the front of the overhead, it’s all fairly unobtrusive. A few anchor points inside the roof for Adel clamps completes the wiring capability, so I now have a 16mm conduit from each side up into the overhead space.

With the conduits clamped, I tacked them in place with some dobs of epoxy. Once that cured, I sprayed fireproof expanding foam into each pillar, around the conduits. I then cut the cured foam down to form the shape I wanted on the inside of each pillar. Once the rest of the overhead and door work is done, I’ll do fiberglass layups over this shape. The foam is a bit rough in parts but it’ll be fine as a base to do the layups.

I have a set of Rosen front/side adjustable visors. At one point when the cabin and overhead were on I established the position I wanted the visor mounts, so that the visors just missed the front strut by about 1/4″ when pushed forward. I made an oval metal mount out of 0.025″ Alclad, with two 10-32 nyloc nutplates in the position of the visor mount screws. I oriented these so that they were minimally invasive in the front pillar, which forms part of the rollover protection and shouldn’t be drilled. These were tacked in place with flox, and the way they are positioned I’ll be able to make them merge in when I do the front pillar inside layups, with a bit of filling and sanding.

I drilled the overhead and installed nutplates for the metal inserts. Also did the cutouts for the vents. The carbon fiber is incredibly hard, I completely wrecked a 2″ consumer grade hole saw after just the four holes.

I 3D printed a drill guide for drilling the four holes in the front strut up through the cabin top. The guide worked great.

At one point when I was sick of fiberglass work, I modified the front seat rails, installing AN4 nutplates so that the seats can be removed easily by undoing two bolts, rather than having to take the rail lock off. This is a well known modification that means the seats can be removed in 2 minutes rather than 10-20 minutes of cussing.

Next step is to fit the door struts, and then take the cabin top out, install the overhead, and start on the layups and filling/sanding I need to do in order to finish the interior surfaces.

  • f26h
    Drilling for seat rack modification
  • f26i
    AN4 nutplates fitted for seat rail modification
  • f26j
    Bolts now go in from the top, making seats easy to remove
  • f26k
    3D printed drill guide for cabin top strut
  • f26e
    Trimming left side door window
  • f26f
    Trimming windshield
  • f26g
    Fitting windshield
  • f26l
    Windshield trimmed, retaining clips in place
  • f26c
    Drilling #6 screw holes in overhead
  • f26d
    Drilling out overhead vent holes, ruining a hole saw.
  • f27a
    3D printing overhead wiring conduit
  • complete
    Conduit to cabin overhead adapter
  • cutaway
    Cutaway view of overhead conduit adapter
  • f27c
    3D printed overhead conduit adapter
  • f27d
    Overhead conduits, visor mounts in place
  • f27j
    Wires will come out of channels and be secured with Adel clamps
  • f27f
    Overhead conduit channels
  • f27i
    Overhead conduit channels tacked in place, plus nutplates for wiring clamps
  • f27e
    Overhead conduits, visor mounts in place
  • f27b
    Tacking overhead conduits and 3D printed adapters in place
  • f27g
    Filled out with fireproof spray on foam
  • f27h
    Foam cut to shape, ready for fiberglass layups