Some time ago I added some brackets to the front of the tunnel, so I could secure the rear heater hose. With Control Approach rudder pedals, the hose needs to be secured in the center of the tunnel, clear of the control arms off to each side of the tunnel. I was going to use a 2″ Adel clamp around the scat tube, based on what another RV-10 builder had done.
After assembling this, I didn’t like it because:
It was difficult to install the Adel clamp, while lying on my stomach with the seats removed and reaching in under the panel. The rear heater hose has to be sort-of scrunched against the short front heater hose in order to get it positioned in the middle of the tunnel.
The large Adel clamp, held by a single bolt, was not very secure and could have a tendency to rotate over time
If anything came undone over time, the compacted rear heater hose would push loose items towards the rear, straight into the rudder pedal arms.
I still had to come up with a solution to replace the standard F-1051J Scat tube support, since this support interferes with the internally run rudder cables when the Control Approach rudder pedals are used.
After a few minutes pondering these problems, the solution hit me – design and 3D print a pair of Nylon brackets to retain the scat tube. The brackets then simply slide onto the scat tube from the rear. For the front bracket, I bolted the Nylon piece to the Aluminium angle retainer on the bench, slid it onto the scat tube, lifted the rudder pedal arms, positioned the bracket assembly and screwed it into position. I also drilled a pair of small holes into the Aluminium angle in order to add a safety wire each side, that way if the brackets ever came loose for any reason, the assembly could not fall aft and interfere with the rudder pedal arms.
For the aft bracket, I had already a long time ago drilled and dimpled the holes on the right hand side of the tunnel for the standard F-1051J scat tube bracket. The lower of these two holes is close to the right hand rudder cable. It would have been better to raise this hole by about 1/2″, but that is ancient history. I resolved this by using a low profile (AN364) lock nut and embedding the nut into a hexagonal cutout in the bracket, as shown in the pictures. I used a pair of 0.063″ shims on each side, with the holes countersunk, to complete the assembly.
It all worked great, both brackets can be easily removed and reinstalled, so any future maintenance that requires removing the rear heater hose for better tunnel access will be easy.
A couple of other RV-10 builders have asked me for the models, and one questioned why I elected to use the metal shims on the aft bracket. I used the shims simply because I didn’t think my consumer grade 3D printer could do a good enough job of the countersinks, when printing them in Nylon, vertically. In any case, I added an option to the model to have no shims, which widens the aft bracket to compensate for the missing shims, and adds countersinks to the sides to allow for the #8 dimples in the tunnel walls. I’ve added pictures of this version. The three STL files can be downloaded using the following link:
I originally mounted a bracket in the empennage for the Garmin magnetometer. Years ago. Then I switched to Dynon avionics, so I was going to have to make a new bracket for the Dynon ADAHRS, and wasn’t looking forward to crawling into the tailcone to install it.
Then I came across the Van’s RV-14 ADAHRS bracket, which looks like a clever design. It goes in the left wing, inside the inner access cover. The RV-14 wings are the same as the RV-10 wings, just shorter. I looked at the drawings and the dihedral appears to be the same, so I ordered the following parts from Van’s:
W-00012A W-00012B W-00012C W-00012D W-00012E
With these in hand, I prepared an installation for the left RV-10 wing using the following procedure:
Prepare the parts using the RV-14 instructions on page 20-03 of the RV-14 wing manual.
When fluting the W-00012C parts, do not simply hand hold the part and hit it with the fluting pliers. Mark the distance in common with the W-00012B parts, and securely clamp the W-00012C between a block of wood and the workbench so that this area remains flat. Then, use the fluting pliers only on the exposed part – see the picture.
Cleco the parts together. Position on the LH inner bottom wing skin, and verify you have the correct orientation.
Draw a line between the center of the two wing rib holes, these are the fourth holes down from the J strut. Reposition the bracket to be aligned with the center of the access cover, and match drill/cleco the end two holes in the Z bracket through the bottom skin. I used a #42 drill bit, and once all holes were drilled, match drilled with a #40 reamer.
Remove the W-00012A bracket, drill the remaining holes from the Z bracket through the bottom skin.
Remove the Z bracket, de-burr the holes just drilled in the Z bracket and the skin. Dimple the holes for flush rivets, and reassemble all parts.
Keeping the bracket aligned so it is not “twisted”, match drill #40 from the W-00012A bracket into the J strut, cleco’ing as you drill each hole. Enlarge all holes to #30. Disassemble and de-burr.
That’s it. I’m not going to assemble the bracket until I prime the parts, but with the pieces cleco’d together I checked the position and clearances. You can see from the photos that there is plenty of room for the cables and air connections. The OAT sensors can be mounted in the bottom wing skin, near the access cover – see the RV-14 instructions for a typical hole position (I haven’t drilled these yet).
The RV-14 instructions call for countersinking the W-00012C retaining strips for AN426AD4 rivets. The strips are too thin for this, the countersink would need to continue on into the W-00012B parts. I see no purpose for using countersink rivets here, so I’m going to use regular AN470 rivets instead, obviating the need for countersinking the parts.
I have to mount the OAT sensors, make up a wiring harness with tie downs and re-route the air lines. I’ll do these jobs once I’m ready to close out the wings.
I’ve hung the engine, which took all of 20 minutes once I worked out how best to do it. It’ll have to come off again, so I’m leaving the engine lift set up. It has to come off again for several reasons:
The biggest reason – I have to do something with the sump oil line associated with the Barrett cold air induction scheme. There’s a VAF thread about it – here. This whole topic deserves a complete post, which I’ll do once I decide how to deal with it. Suffice to say, it is a nasty issue but until I have a strategy for this I can’t oil the engine.
With a B&C 90 degree oil filter adapter, the B&C 462-3H vacuum pad mounted alternator requires a 1.25 inch extension, which I mounted after changing to the correct studs. However, the clearance between the field wire connector and the firewall is not adequate. I’m going to modify the connector and bring the wire out the side so that there is adequate clearance. To do this I have to remove the engine.
While the engine is on, I’ve taken the opportunity to get out all the boxes containing everything that gets added to the engine, and verify that it all fits and I have the correct hardware. I found a few things:
The studs that Barrett installed for the PCU-5000X Governor are too short. They are probably the 3C-17 studs that are in the Lycoming parts list. They should be the 3C-19 studs, so I have to order four of these, remove the old studs, and install the longer ones before I can install the propeller governor.
The exhaust pipe for the #3 cylinder looks like it will impinge on the induction pipe for that same cylinder. If so, I’ll have to get that pipe modified.
I don’t have the engine mounting parts for the A/C compressor. I knew about this.
The A/C compressor will get in the way of the left air intake, requiring modification to the intake. I knew about this also.
One job I was able to complete with the engine on – I put a 1″ tie down strap between the front fork and the engine, cranked it down, and was able to easily compress the elastomers enough to get the retaining bolt in – without the engine on to establish the right leverage points, this is just about impossible.
I also made a doubler and drilled the fuselage to install the front ADSB antenna under the passenger seat.
I’m an unusual builder – I’m almost 3,000 hours into an RV-10 slow build, and I’ve never even sat in an RV of any kind, let alone flown one! I spent most of July on holidays in North America, including three days at Osh Kosh, and after the main trip was over I traveled to Vernonia, Oregon, where I flew the Factory RV-10 with Mike Seager.
Mike is a great instructor, and has been doing Van’s RV transition training for a long time. Despite some marginal weather at times, we managed to fit in five flights across the three days of August 7, 8 and 9, for a total of 9.2 hours RV-10 time in my log book. We visited 5 different airports during this time, plus the grass strip at Vernonia where Mike has his hanger.
It took me a few hours to catch up with the RV-10, I was hopelessly behind the thing on the first flight. It accelerates and climbs so quickly compared to the Cessna’s I’m used to flying, and the circuit procedures have a different slant as well. During an evening trip to Astoria airport, I finally “got it”, and in perfect conditions with the airport basically to ourselves, I did about ten “stop and go’s” in the fading light.
I’m a bit early doing this training, but couldn’t resist the opportunity to fly a few hours in the USA with such an experienced instructor. The Factory RV-10 costs U$75 per hour, wet (I think it has now gone up to U$80), which is ridiculously cheap especially by Australian standards. Mike explained to me that it is Van’s policy to actively encourage people to fly the aircraft, firstly in order to promote the sale of kits, and secondly to encourage builders to undertake adequate transition training.
I’ll probably do the same thing again in the Northern summer of 2020, when I hope to be close to first flight.
I had my third technical counselor visit on 25 June 2019. Since there are no counselors currently residing in Tasmania, I’m very fortunate that my TC, Brian, is prepared to fly down from interstate for the day. We had a good session on the Fuselage progress in the morning, went to lunch, and visited a friend’s RV-9A project in the afternoon.
I’ve been on a mission since April to get the fiberglass work on the Cabin Top and Doors behind me rather than in front of me. It’s been a bit of a marathon, the cabin top molding is not famous for its accuracy and everything has to be hand crafted to fit. Here’s the finished product:
I had planned to roll the thing in and out of the workshop to help with this work, but the weather’s been too cold to safely work with the plexi or cure fiberglass, so it’s all been done inside. I’ve had a pair of heaters going in the workshop 24/7 for the past month, and was finally able to turn them off last night. The shop vacuum copped a beating during this time, and I had to regularly clean out the filter.
Here’s all the steps I went through to get this job done. Skip to the end for the pictures.
1. Fit the rear windows
I used Lord Adhesive (available from Aerosport Products) for all windows. The forward surface of the rear windows needs to line up with the aft surface of the doors, which means spacing the windows up from the fuselage molding. I then built up the rear door pillar with a few layers of fiberglass cloth and flox until it matched. There is a flat spot on the left hand door pillar of all RV-10 cabin top moldings, this was the worst place and had to be built up about 5mm – too much for just micro/filler.
I used West Systems G/Flex with some microballoons to fill in any voids not filled with the Lord Adhesive, and trimmed any excess Lord Adhesive with a scalpel. I then taped and scuffed the window (and fuse), and applied 3 layers of fiberglass cloth on the outside. After sanding any high spots, and scuffing, I used regular West Systems epoxy with microballoons and Cabosil to fill and blend the outside surfaces into the cabin top.
2. Paint the inside door sills and cabin top pillars
The lower cabin top pillars had to be blended in, and painted, along with the door sills, to match the rest of the interior. This painting is best done before the front window is installed. Unfortunately, the inside of the cabin top and overhead is already finished, so I had to mask it all off with cardboard and tape. I didn’t want to have a yellow polyurethane primer leak splattered across the ceiling. This all took a fair bit of time, and I wound up spraying each side in sequence rather than together, because I didn’t trust myself leaning across wet paint to get to the other side.
The job took time but went OK, and you can’t tell where the paint transitioned into the existing painted part of the pillars.
3. Install the windscreen
Once again I used Lord Adhesive. It helps to have a second person helping, cleaning up any excess adhesive squeezed out on the inside using Q-tips and white spirit. I used a combination of clecos and weights to hold the plexi in position while the adhesive cured.
3.1 Extend/fill lower edge and prepare for fairing
I scuffed the upper forward fuselage area, acid etched it, and wiped some Alodine over it to prevent the oxide re-forming. I then filled the lower edge of the windscreen using Micro-balloons, with black dye to prevent it being seen from the inside. After the micro cured, I sanded it to align with the outer surface of the windscreen, taped off and scuffed the windscreen. All I used to figure the tape position was a cardboard cutout section with a 7 inch radius.
3.2 Construct the windscreen fairing
Once again using black dye. Preparation is the key to this layup, I cut all of the glass cloth strips, and allowed several hours to do this in one operation. It worked out quite well and a day later I sanded it into the correct shape, using a wooden block cut with a 7″ radius (using the band saw). I used a stick-on flexible perma-grit strip for this operation, which surprised me by staying in place. Gotta be very careful though, not to encroach onto the tape because the coarse perma-grit is a weapon.
After this I switched to 80 grit sandpaper, and finally 120 grit to carefully sand down to the top layer of tape. I used micro to fill low spots. It took a few iterations to get the entire fairing correct, and blend it into the fuselage at each side.
3.3 Glass in windscreen over the top
Fiberglass cloth across the top and down each side, once again fairing it with micro, matching it with the front edge of the door. To do this, I used packing tape on the door as a release agent, slathered micro through a section of the pillar, and closed the door onto it. The following day, a hard yank on the door would release it, and I can sand down any excess.
4 Door edges and cabin top alignment
Whenever I use packing tape as a release agent, I apply it over a layer of masking tape. It is easier to get off, and then any goo left behind simply comes off with the masking tape.
I worked sections of the doors at a time, applying micro to the pillar edges or anywhere that required building up, closing the door with packing tape in place, letting it cure, and then opening the door to release it. This is a good reason to leave the door windows out and fit them last – you’ve got the entire window opening to use rather than the door handle, and in some cases it requires quite a yank to release the door.
4.1 Door gaps, fairing across the top of the door
At this point, the doors closed properly but with basically no gap. Starting at the very top, I used a small piece of 120 grit sandpaper, and worked it from side to side through the gap, closing the door until it jammed, then lifting the door a fraction so I could keep sanding. I mostly sanded the cabin top – since it was micro and easy to sand, but also since the doors already had a nicely formed flat angle which I didn’t want to distort.
Once I could move the sandpaper side to side with the door closed and locked, I moved onto the front and back curves and did the same thing, working my way down each side in turn. Finally I sanded across the bottom and around the bottom corners, getting to the point where I could insert the 120 grit paper, and with a bit of friction still there, slide it all the way around the door.
I measured the 120 grit paper at about 0.01″ thickness. The gap will need to be wider prior to painting, but at this point I left it as is – as long as there is a gap the door is hanging freely, attached by the hinges and the door pins only. Setting up this gap allows the door to drop slightly, maybe a fraction of a mm. This required a bit more fairing work around the top of the doors, to match the door level with the cabin top.
4.2 Bottom of the doors
The bottom of the doors was a close match to the outside of the fuselage, aligned within perhaps 0.5mm across the entire length, but it is a simple matter to match it precisely. Once again, using packing tape as a release agent, I built up the door where required, and the surrounding fuselage area(s) where required, with a thin layer of micro, and then sanded it back to get an exact matchup. This introduces lots of pin-holes which of course have to be filled later.
4.3 Check the seal gap
Since the doors adjusted position a “bit” with the initial gap set, it’s important to go back and ensure that the “seal” gap for the McMaster seal is still correct – between 1/4″ and 5/16″ in my case. I made a few adjustments across the top on each side.
5 Fit the door windows
With the doors an exact match and a 0.01″ gap all the way around the doors, it was finally time to fit the door windows. These are the easiest windows to fit, you can take the doors off and use gravity to your advantage.
6 Optional – prime and fill pin-holes
I elected to spray on some primer and surfacer to seal everything up and fill almost all of the pin holes. I only sprayed two layers of surfacer, sanding most of it off each time. There are still some low spots, it’ll need more work prior to painting, but it’s good enough for now.
All of these operations took two months to complete, and it was with some relief that I took all the masking and protective film off, and wound up with a good result.
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.
My current plan is to get the airframe up on the gear so I can roll it in and out of the workshop to do the remaining fiberglass work outside. I decided to do a trial fit of the Avionics before doing this, just to make sure everything fitted properly after riveting together all of the sub-panel brackets.
The trial installation took about 3 hours, and no adjustments were required. I only did the minimal amount of wiring to get power to the panel, installing a single master switch controlling the primary (left) system master solenoid. Power came from a car battery on the floor next to the baggage door. I left out the Transponder/ADSB system, the Avidyne IFD didn’t have a GPS antenna, and of course with no engine there were no EMS sensors. I taped a COM Antenna, and the Dynon GPS puck, onto a chair outside the workshop. I ran the ADAHRS cable through one of the conduits and connected the primary ADAHRS only, sitting on a shelf in the rear. Didn’t worry about the harness cables much, just crammed them in – a real installation will take a lot longer when it happens.
It all worked at first turn-on, apart from warnings associated with the pieces that were left out / not connected. Nothing calibrated but I was able to use the COMM’s, enter flight plans, wobble the ADAHRS and see the screens update correctly etc. It was a useful exercise and helped firm up how I was going to route some of the wiring.
Now I get to take it all out again (which won’t take long) and get back to the plan – up on the gear and a month or so back in fiberglass hell.
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!
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.