Saturday, February 17, 2018

Section: 23
Hours: 6

We are having more unseasonable warm weather (70 degrees in the afternoon) so I decided to prep and prime some parts. Here are the aileron push rods and end caps, the GMU-22 magnetometer mounting bracket, wing tip ribs and the elevator gap closure fairings. I also spent some time cleaning up the garage some.

I also spent some time working out more details for the wing wiring. I will be using the Van's provided wiring harnesses since I already have them on hand. From my initial research it looks like I will have to provide additional wiring for several items:

1) The FlyLEDS wingtip LED strobe lights may be electrically noisy so it is recommended that they be wired using a shielded pair of 18-22 ga. wire.

2) I will be installing a GAP-26 regulated pitot heater that requires additional wiring runs for power and the sense line that attaches to a G3X annunciator.

3) I think I'll be mounting the outside air temperature (OAT) in the left wing and it will require extra wiring.

4) I am going to use an Archer nav antenna embedded in the right wing tip and it will require a coax cable run.

Friday, February 16, 2018

Section: 12
Hours: 4

This morning I got out the rivet gun, bucking bar and drove some rivets. It's been a while but it all came back to me - like riding a bicycle at this point in the project.

Section: 23
Hours: 3

This afternoon I started work on the aileron linkage. Here I've installed the aileron bellcrank. The first time I started tightening the end nut the bell crank got tight, so I removed it and lightly sanded the inside of the pivot tube. It now moves freely without any slop.
I had previously started the fabrication of pushrods. Today I cleaned out the inside of the tubes with sandpaper wrapped around a broom stick and then taped off the ends and poured epoxy primer into the tubes. Tomorrow I'll prime the outsides.

Next I fabricated the push rods. I had previously primed the inside of the tubes. The threaded ends are held in with (long) AN470AD4-11 rivets. The manual advises using a hand squeezer on these because it is easy to lean them over. I don't have a hand squeezer so I decided to back rivet them, which worked really well. I placed the back rivet plate on the table, inserted the rivet and then held the rod in one hand so the rivet was vertical to the rivet plate and the rod was parallel to the plate. Then I aligned the rivet gun vertically on the end of the rivet and gently tapped the rivet into the back plate to get the initial set. It was easy to control the rivet using this setup.

I finished up this afternoon by inserting threaded rod ends into the torque tube sub assemblies with pull rivets.

Thursday, February 15, 2018

Section: 12
Hours: 8

After fitting and match drilling the empennage fairing you do a final trim. You must maintain at least 3/16 inch of margin to the center of all the screw holes. A couple holes on one side of my fairing were too close to the edge, so I had to adjust the trim line out about 1/16" in a couple places. That's why you leave a 1/8 inch margin in the initial trim. I used masking tape to mark the required trim line and cut within 1/16" with the dremel. Then I used a long board with sandpaper to sand to the tape line for a nice straight final trim.
After sanding all the edges to the final trim, I rechecked the fit on the airplane and made a few more adjustments in the saddle areas to close all the gaps to less than 1/32 inch all around. Then I applied a half round to all the edges using a sanding block to first apply a 45 degree bevel all around and then I knocked the edges of the 45 bevel off with the sanding block. I did the final rounding using sandpaper held in my fingers. I should mention that I frequently run the shop vac to keep the fiberglass dust from accumulating (did I mention I hate fiberglass dust ?).
The next step is to add nut plates to the h-stab, v-stab and fuselage. I was able to use the squeezer to rivet the nut plates on the h-stab and v-stab. Then, as I was inspecting the fuselage under the horizontal stabilizer, I discovered that I was missing a row of rivets (see felt marker arrows below). I must have mis-read the manual a few chapters back. There was no way I could do all that riveting with the tail feathers in place so I spent the rest of the afternoon removing the elevators, h-stab and v-stab :-( Two steps forward, one step back...

Wednesday, February 14, 2018

Section: 12
Hours: 7

Back to fiberglass work. Today I tackled fitting the empennage fairing. The fairing is provided oversize with a final trim line scribed in the top coat. The trim line is hard to see so I traced over it with black marker.

The fairing is too bulky to run through the bandsaw so I used my dremel tool with an abrasive cutoff wheel. The dremel tool kicks out lots of abrasive fiberglass dust while cutting so I run the shop vac and hold the hose close to the cutoff wheel to catch the dust before it permeates every corner of the garage. There is nothing worse than itchy, abrasive fiberglass dust all over the shop :-(
Since I use one hand for the shop vac hose and the other hand for the dremel, I clamped the fairing to the work table to keep it from moving.
 After doing the initial trim leaving 1/8 inch extra margin you fit the fairing to the empennage. The trick in fitting is to get the saddles on the leading edge of the horizontal stab to have less than 1/16 inch of gap. You do this by trimming back the vertical stab saddle and by thinning some of the thicker spots of the fairing. I had to trim about 1/8 inch inside of the scribe line in the vertical stab saddle area to get a good fit. The fairing is flexible so a good fit is helped by using some body english as well as trimming.

Next you place a light inside of the empennage area to illuminate where the screw holes are and drill #40 holes in the fiberglass to match. It's important to tightly hold the fairing in place to maintain the close fit to the h-stab saddle areas. The manual suggests taping it in place, but I couldn't get the tape to hold securely enough and I wasn't confident it wouldn't shift.
The fit looks really good at this point. Everything is lying down and the saddle gaps are very small. The mold for the fairing is very accurate. I've seen some other RV's that had to use lots of flox and bondo to get a fit this close. I'm very impressed with the quality of the RV-14 fiberglass parts so far.

Tuesday, February 13, 2018

Section: 12
Hours: 5

I cleaned up the v-stab tip and riveted it in place.
Yesterday I inset the end bulkhead about 1/8 inch and applied a flox fillet to allow internal clearance from the rudder through full throw. Here is the result riveted in place.

Next step didn't involve fiberglass!!!! Here is the fairing that attaches below the horizontal stabilizer. I used a couple boards and clamps to hold the fairing and bent the angles called out in the manual.
The fairing attaches with #6 screws. I slightly broke the lower edge of the fairing to generate a tighter fit.
 Here is how those bends transition the fairing from the vertical stab down to the fuselage.

Monday, February 12, 2018

Section: 12
Hours: 4

I made a template for the vertical stab tip end out of 1/16 inch plywood and carefully sanded it to fit. Then I transferred the shape from the template to the fiberglass / balsa sandwich panel and cut it to final shape. I then bonded the panel into the tip with flox thickened epoxy and glass cloth tape.
(sorry no pictures).

Sunday, February 11, 2018

Section: 12
Hours: 5

I made a template and laid up a fiberglass/balsa sandwich panel to close the end of the v-stab tip and set it aside to cure.

Next I sanded and cleaned up the h-stab tips. Yesterday I had glassed in a bulkhead in the noses of the tips to push them to a fuller shape. I also added a fillet of flox thickened epoxy to the round the outside face of the end bulkhead. This will create a shape that allows for good clearance of the elevator through the whole range of throw.

Both tips are now final fit and riveted to the horizontal stabilizer. There are still a few small gaps that will have to be faired with filler, but the final fit is pretty good.