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Cabin Top Cosmetics

The cabin top has been fit to the fuselage for some time, but all the work wasn’t finished.  The outside of the cabin top was in a fiberglass mold, so its surface looks pretty good.  The inside is a different story, though.  There are some uneven areas visible from the inside, and unfortunately, not all of it will be covered by our interior, namely the area around the doors and windscreen.  Because of this, we’ve been filling some of the areas with an epoxy/microballoon mix, which requires quite a bit of sanding.  Here are some pictures of Kelly sanding (and no, I wasn’t just watching; I was working on something else).

Finished fitting the doors

As I mentioned before, the doors are probably the most notoriously difficult/tedious part of the RV-10 build.  Though we’re not completely done with the doors, I’m happy to report we’re done with the fitting.  Both doors have the latches and door blocks installed, and both doors close and latch relatively easily and fit the fuselage fairly well.  We still need to build up the cabin cover (big pink thing) in some areas to match the level of the doors, but that’s not a big deal.

Still remaining on the doors: installing the windows and finishing/priming/painting the parts of the doors that won’t be covered by the interior.

Cabin Door Blocks

These aluminum blocks aren’t part of the kit–they’re one of the many aftermarket “mods” (modifications) that are available.  These give the door pins extra engagement, which provides greater assurance that the door will stay closed.

Riveting the last skin!

The upper forward tailcone skin is left open for a while, because it provides good access to the stuff installed in the tailcone: an elevator bellcrank, pitch servo, ELT, ELT antenna, GPS antenna, strobe ballast, master relay, and battery box.  With all these things done and wired, we wanted to attach the skin so we could work on the transition to the cabin top, so it was time to rivet again.

Here it is partially done.

Here I am sitting in the tailcone.  I had to do a lot of leaning to get at all the rivets.  I won’t miss doing this.

Here’s Kelly doing the last row of rivets.  These are pulled rivets that go through the skin and fiberglass cabin top, so she was able to do these herself.

Gluing the Rear Windows

Time to start attaching the windows.  There are 5 windows (or “transparencies” as the plans say): one rear window on each side, one window in each door, and a windscreen (a.k.a. windshield).  The process before gluing is basically:

  • Rough trim the window to the hole in the cabin top
  • Keep trimming/sanding until it fits well
  • Check the fit of the window in the hole, and use shims as required to make the outside of the window flush with the cabin top
  • Mask the window where you don’t want glue
  • Scuff up (sand) the area of the window where it will attach to the cabin top, so the glue actually sticks to it

Here I am doing some test fitting.

After that, it’s time for the gluing.  The plans recommend using something called Weld-on 10.  Several builders have experienced crazing (tiny cracks) using that, and the theory is that it’s because people use too much pressure to hold the window while the glue is curing.  Because of that, there are many different methods people use to attach the windows, but we decided to go per-plans and use the Weld-on.  To hold the window in, we drilled holes in the cabin top and used clecos and popsickle sticks to hold it in place with slight pressure.  We also thickened the Weld-on with cabosil, which also created more volume.

How were the results?  Not bad.  The window required significant shimming to make it flush with the cabin top, so that created a big area for the glue to fill.  There wasn’t quite enough, so there were some voids when the glue dried.  Nothing too major; the glue will be sufficient to hold it on.

Here’s what it looks like in place.

Here’s the biggest glue void.  You can also see I’ve filled in the gaps with epoxy.

Mounting the remote compass

Did this a while ago, but just getting around to documenting it.

All the sensors for the flight instruments are in the same box as the display (on the instrument panel), with the exception of the remote compass, the little box that tells you which direction the airplane is pointed.

This one is separate because it needs to be installed away from any ferrous metal and electrical currents, including the mounting hardware (so you need to use brass or aluminum screws/washers/nuts). I mounted it in the tailcone, by the bulkhead aft of the baggage wall, on this little “shelf” I designed and built myself out of aluminum sheet and angle. As you can see, it’s far from everything here. Later on there will be seatbelt anchor cables running near here, but that should be acceptable. Note also that the box is tilted slightly–its tilt needs to match that of the instrument panel, which is tilted about 8 degrees so the panel is pointed slightly “up.” Anyone see anything wrong with the picture above?

Answer: the compass is tilted the wrong direction. Oops–will need to fix that.

Door latch pins

These pictures are of the left door, but I’ve completed this step on both doors.  The pins, extend out of the bottom of the forward and aft sides of the door and into the door frame, keeping the door closed.  The Van’s stock design is unsightly and is easy to do in such a way that you don’t get good engagement of the pins.  Instead, I opted to use the aftermarket pins tips from iflyrv10.com.  You basically cut off the angled end of the pin, then tap the inside and screw on the pins.  I had to cut a little extra of the pins to make everything fit right.  Basically, when the door handle is all the way in the open position, the pins should retract just barely all the way into the door.  This ensures there’s enough clearance in the door frame to shut the door, but when the door handle is closed, you get sufficient engagement of the door pins.

Here’s what the pins look like when the handle is in the open position.

Here’s what they look like when the handle is in the closed position.

This is the hole in the door frame that the forward pin goes in.  There will also be an aluminum block attached to the frame to give the pin extra engagement.  These doors aren’t going anywhere.

Working on the right door

I did the right door initial trim after gluing, and am very pleased with how it matches the contour of the cabin top.

Now that the door fit well *on* the cabin top, it was time to trim it to make it sit *in* the cabin top.  I got it to fit reasonably well, so then it was time to attach the hinges.  Kelly got a couple shots of me doing that.

Once the door fit well enough to shut completely, I installed the latch mechanism.  No pics of me building it, but here’s what it looks like installed.

Note the exterior handle is missing.  We’ll do that later.

Here’s a picture of the worst fitting part of either door.  On the aft side of the right door, the door sits as much as 3/32″ above the canopy top in one place.  We’ll definitely need some epoxy/micro to make that look decent.

More work on the left door, gluing the right door, more FWF

In the last week, I continued fitting the left door, getting it to the point that it’s mounted to the hinges and can open and close reasonably well.  I’m waiting until I have the door seals (from McMaster-Carr) before doing the final fit.

In the mean time, I trimmed and we glued the halves of the right door.

We also continued working on the hinges that mount the cowl to the fuselage.  These are aviation versions of regular piano hinges.  One side is riveted to the fuselage, the other side to the cowl (the big pieces of fiberglass that cover the engine).  To remove the cowl, just pull out the hinge pin.

We also finished riveting the oil cooler box to the firewall.  The flanges didn’t end up completely flush, but it really doesn’t matter.  I’m glad i don’t have to climb back under the instrument panel for a while.

Next up: more fitting of the left door and finishing the cowl hinges.

Starting the doors and FWF

Last weekend, Kelly and I started two major tasks: doors and firewall forward (FWF).

The doors on the RV-10 are notoriously difficult and frustrating to get right.  You have to fit them just right on the cabin top, which involves a lot of sanding, fitting, sanding, fitting, sanding, filling, sanding, more sanding, etc.

Each door comes in two parts, an inside and an outside.  The first step is to rough trim each part.  Then, you mix up some epoxy and thickener and spread it between the two sides, then cleco and clamp it to the fuselage while it cures.  This ensures the curves of the door at least approximately match those of the fuselage.

After that, you cut the edges to fit in the door frame, then start sanding to get things to fit just right.  It’s not perfect yet, but it’s close enough to mount the hinges to the doors the next time I work on it.

I also started working on the door handles and latches (not pictured).

While I was doing this, Kelly started on the firewall forward section.  This is basically everything that goes in front of the firewall: engine mount, fuel and oil systems, engine, etc.  The first steps involve mounting a few of the accessories to the firewall.  Kelly mounted the fuel and oil pressure sensors (top center in picture below), oil cooler (lower right), and brake fluid reservoir (not pictured).  We’d previously installed the heater boxes (left in the picture), which control the amount of heat in the cabin.

Next up: more sanding!  Kelly has started working on the hinges that attach the cowl to the fuselage.