Mark's Most Excellent RV10 Build Site | Building the dream, one rivet at a time

Prime/Paint (1)

18-Oct-2020 14:28 ⋅ Leave a Comment ⋅ Mark

Now that many of the main components have been built, the next steps are prime and paint before final assembly. The tail section and smaller removable parts were the initial targets for this activity. I have been priming interior parts throughout the entire build, but this was my first experience with PPG CA7504 primer. The decision was made to switch to this product, which is specifically designed for airplanes. This primer is formulated with the elastomers, fillers and other ingredients for the flexibility needed to withstand rapid temperature changes, as compared to general automotive paints. This primer used in conjunction with PPG Aerospace topcoats prevents cracking, improves surface adhesion, and helps the mechanical characteristics of the paint layer.

The effort needed for painting takes considerable time, but is really not worthy of new posts. I intend to prime all exterior components, then seek assistance from someone to spray the final topcoats. I can perform the drudge work of preparations due to the time/cost involved, but am not confident enough to shoot a smooth, final surface. We shall see how this strategy goes.

The general steps of surface preparation, mixing and spraying are the same as the previously used on interior parts using automotive PPG DP40LF primer. The new material requires greater attention to mixing ratios, measuring induction time with a Zahn #2 viscosity cup (15-18 seconds) prior to application, and modifying the application technique.

Wing tips, rudder caps, and empennage parts were in the first batch. The outcome of the initial session were very poor, with runs and fisheyes. Subsequent attempts after sanding smooth and more rigorous surface preparations were much better. Additional filters were installed in the pneumatic air lines, and the lines were thoroughly purged of water and debris. Plus using higher quality Techline gun for better atomization and holding the gun further from the surface seemed to help. A few cycles of spray practice on the first batch have improved my technique to eventually yield good results.

Preparation steps include using a maroon (=320 grit) Scotch Brite pad in a palm sander to scuff the surface, clean with degreaser, condition with Prekote, then apply primer.

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The second batch on rudder and trim tabs worked out well with only one application session. Next up are elevators, ailerons, flaps and the horizontal stabilizer. The wings and fuselage will be last. More updates will be forthcoming when significant progress is made.

Rudder (close-up and after second prime)(October)

Ailerons (before and after priming)(October).

Elevators (October)

Oil door opening (November)

Oil door cover (November)

Flaps (November)

Horizontal Stabilizer – tip (November)

Horizontal Stabilizer (November)

COWL HINGES

The upper and lower engine cowlings are attached to the firewall with 1/8″ PIANO HINGE. The initial sides and bottom pieces are shown.

Fabricated parts ready for fitting. The right photo shows the initial layout, then match drilling occurs next.

Hand squeezing the side rivets was not so easy. The angle of the firewall-to-side and interference with the squeezer head was an issue. An number of rivets were later redone with a pneumatic jaw-type squeezer.

Final results were not great, but acceptable.

Posted in: Prime/Paint, RV-10 Build Project, Section 47, Spinner and Cowling

Wing Root Fairings (1) and Seat Brackets

17-Oct-2020 20:37 ⋅ Leave a Comment ⋅ Mark

Bending metal for the wing root fairings and making brackets for the seats were the tasks for this week.

To achieve the correct bend of the fairing attach brackets, they must first be clecoed at one end. Flute pliers are used to align the pre-drilled locations in the fuselage mid-skins with the brackets.

The fluting/bending process continues until all brackets align. The holes are then match drilled to final dimensions. These photos are show the forward brackets.

Here is the rear bracket. Another task prior to wing attachment is relieve the main spars where the bottom skins attach. Note the amount to be removed marked with a black Sharpie. The removal was by hand with Pferd files.

SEAT BRACKETS

The forward seats require additional brackets (not included in the quickbuild kit). The standard process for file, deburr, scotchbrite, brightener, alodine, prime, paint, and rivet was applied.

Posted in: RV-10 Build Project, Section 44, Wing Attachment

Control System (2)

17-Oct-2020 19:59 ⋅ Leave a Comment ⋅ Mark

Previous posts described the rudder cables installation. Here the final tabs were measured and installed.

Here are photos of the rudder pedal linkages and the rudder attachment.

Fairings were added to the cables outlet locations for added strength and a touch of streamlining.

EMPENNAGE FAIRINGS

Experience from other builders indicate the holes tapped in the longeron for the #6 screws holding the empennage fairings will eventually strip out from taking on and off. While the tail section has not been completely sealed and the access was relatively easy, I added Click-Bond nutplates.

Posted in: RV-10 Build Project, Section 12, Empennage Fairings, Section 39, Control System

Transparencies and Miscellaneous

17-Oct-2020 19:20 ⋅ Leave a Comment ⋅ Mark

The Lexan/Plexiglass transparencies used for the rear and door windows were bonded with Lord 7475A/D two-part epoxy adhesive. These parts were trimmed to size and smooth sanded in prior posts.

Electrical tape provided protection on the rear windows during roughing the inner surface with 120 grit sandpaper to enhance adhesion. Then the window frames were taped so excess adhesive could be easily removed.

Shims in the form of AN960-10 and AN960-10L washers were placed to bring the window surface to level to -.010 inch of the canopy. This helps with the physical holding of the window, plus will allow for later blending with filler to a smooth transition.

The bonding process was a bit scary – only one shot to get it right. The reason is the Lord adhesive cures very quickly and is extremely difficult to remove after it sets. Fortunately the rear windows turned out fine.

The same method described above was used on the door windows. Straps and clamps hold the windows tight to the frame while the adhesive cures.

GMU MOUNT BRACKET

Previously a mounting bracket for the Garmin GMU 22 magnetometer was fabricated for placement in the mid-tail section. The angle of the bracket should be as close to zero degrees level with the fuselage waterline during flight as possible. It was determined with a digital protractor that the bracket needed to be adjusted about 1.8 degrees down to meet this requirement.

The bracket was constructed so that brass screws adjust the tilt angle of the magnetometer platform to the flight waterline. More on that adjustment in a later post. Here the GMU bracket is positioned along the plane centerline

The GMU bracket seen from above and below after priming from the hole drilling. Note the use of brass screws and stop nuts. According to vendor specifications, any magnetic components should be at least 2-3 feet from the magnetometer. The location of the bracket in the tail should achieve this goal.

These pictures are the final fit of the GMU bracket to the custom platform.

Posted in: Custom Elements, RV-10 Build Project, Section 43, Cabin Cover, Section 45, Cabin Doors and Transparencies

N190XB 3D Panel

27-Sep-2020 09:54 ⋅ Leave a Comment ⋅ Mark

This page makes available a Blender 2.79b file containing a baseline instrument panel configuration for my airplane. Note: this file and the download page are a work in progress and may be updated/removed at any time.

N190XB 3D Panel v01

1 file(s) 75 MB

Download

Posted in: Downloads

Empennage Attach (6) and Custom Elements

01-Aug-2020 18:56 ⋅ Leave a Comment ⋅ Mark

The latest steps were in completing elements of the empennage attachment sequence. All the actions were of an interim nature, further posts on all elements will follow.

The last hole in the longeron at the rear of the vertical stabilizer required a nutplate install. The rudder had to be off to access the rivets.

Then install the rudder to test fit the cable linkages. The default lengths in the plans of 1″ on for aft pedal and 2.25″ on the forward pedal did not align the rudder to neutral. Further adjustments were required.

FLAP POSITION SENSOR

According to literature, many folks recommend using a Ray Allen POS-12 position sensor instead of the default AirWard configuration. A bracket was made earlier for the sensor, then a provisional lever mounted to a 2-piece collar clamp was used to test the throw length and hinge positions.

STATIC LINES

A custom bulkhead configuration of 3/4 rubber grommet, then a push-to-connect pneumatic fitting connected to NPT-AN4 adapter was made for the forward 1/4″ Verstube termination.

The static tube pulled through the cable runs was aluminum instead of plastic. I wanted to ensure this would never require a replacement after the plane is finished.

A similar fitting configuration was used in the rear for a permanent attachment. A custom mounting bracket uses the existing lighting hole as a pass-through. Standoffs will hold the plastic lines from the external static ports.

The aluminum tube was run up the bulkhead rear. It is fastened with 1/4″ diameter Adel clamps and will be terminated at the push-to-connect tee.

The final configuration still needs to be tested with soapy water for minor leaks. However, once tested, the ‘home run’ of aluminum tube through the mid-fuselage should never require additional maintenance (at least that is the intention).

EMPENNAGE FAIRING

Finally the gaps between the raw empennage fairing and the horizontal stabilizer were removed with SuperFil.

Posted in: Custom Elements, RV-10 Build Project, Section 11, Empennage Attach

Empennage Attach (5) and Empennage Fairings (7)

25-Jul-2020 12:44 ⋅ Leave a Comment ⋅ Mark

Attachment of the horizontal stabilizer enabled the final configuration of the elevator control rods and elevator stops.

Match drilling the forward spar shims and aft bracket were performed to mount the horizontal stabilizer. The UP position of 30 degrees exactly matches specification. The DOWN angle, even after considerable filing of the stop bracket, was finalized about a degree shy of the expected 25 degrees.

These pictures show the vertical stabilizer forward and aft attachments after the elevators were removed. Two mounting shims under each forward HS spar attach pad were also match drilled and bolted on before VS install.

The empennage gap cover under the HS was clecoed into place. The rear section overlaps the inspection port cover. Both are match drilled together through the longeron.

The plans call for only three screws per side to hold the forward section of the empennage fairing. Many pilots have suggested additional fasteners to prevent fiberglass bulging due to air stream pressure over the fuselage. Here intermediate points were drilled midway between the default points. Nutplates for #6 screws will later be added to the upper aft skin.

Front and rear photos of the match drill screw points on the empennage fairing. The aft points require special care when trimming to not interfere with either the elevator horn or the rudder motions.

With the main empennage components staged in place, the whole fuselage begins to look like an airplane.

OCTOBER 2020 UPDATE

Further trimming and edge preparation has been completed on the fiberglass empennage prior to priming.

Edges were measured against a scribe line formed into the part. Enough ‘meat’ needed to remain for the attachment screws to have sufficient structure to hold properly.

Because of the extra holes added, smooth curves based on circular patterns were applied. Since fiberglass always seems to have numerous pinholes from the manufacturing process, a coat of Smooth Prime helps with initial underlayment.

MISCELLANEOUS

The forward and aft NACA air vents were fastened with ProSeal and #4 stainless screws into position. Later SuperFil will be applied to smooth out the backing plate rivets.

Posted in: RV-10 Build Project, Section 11, Empennage Attach, Section 12, Empennage Fairings

Flap System

05-Jul-2020 10:32 ⋅ Leave a Comment ⋅ Mark

Next section was installing the flap levers and Pittman flap motor from Vans.

The UHMW (ultra high molecular weight) guide bearings must be relieved to fit under the kick plates in the rear footwell. The various stages of the trimming process are depicted on the left. The right photo was taken during match drilling AN3 bolt holes in the flap crank and torque tubes.

Proper alignment of the flap crank with the flap horns was achieved by clamping the center crank to the workbench, then using the W-730 Bellcrank Jig to establish the correct angle on the horn. Curiously these call for AN4 bolts, while those for the flap crank are specified for AN3.

Insertion of the torque tubes was supposedly achievable from the inside the footwell, but I found pushing through the exterior access holes to be much easier. The quick build exterior holes first needed to be relieved slightly to prevent binding on the torque tubes.

The flap motor comes without an electrical connection. The left picture shows a Molex 18-24AWG connector crimped into place. The wires near the connector are held together with heat shrink. The flap crank with UHMW bearing are shown on the right.

These photos show the final configuration of the flap motor to flap crank, plus a close-up of safety wire around the pivot point. It was a slow, tricky job to drill a 1/16″ hole in the motor pushrod. The final attachment of the flap horns will be performed after the wing root area is primed and painted.

A custom flap position sensor mount is fabricated for a Ray Allen POS-12 device. More on this later…

Posted in: RV-10 Build Project, Section 40, Flap System

Control System (1)

05-Jul-2020 10:24 ⋅ Leave a Comment ⋅ Mark

The recent activities were dictated by positioning new equipment in the tunnel and forward fuselage. As a result strict adherence to the sequence outlined in the Vans plans were required, otherwise some installations out of order would be extremely difficult, if not impossible).

The elevator idler arm was deburred, primed and riveted together. This piece is located in the tunnel between the rear seats and connects the forward elevator pushrod to the mid-fuselage pushrod.

These are photos of the control and flap system parts before fitting, drilling and deburring. The right picture shows the aileron pushrods which link to the control stick bases.

The control stick bases were reamed for roundness after drilling the control stick itself, then were protected with tape and expandable ear plugs prior to priming the ends. The brass bushings were then driven into the pivot holes for a snug fit.

The control column was installed with finger tight stop nuts, then the control stick bases and pushrod assembly were also loosely attached. After adjusting the length of the pushrod assembly to ensure the control sticks were parallel, all fixtures were tightened and Torque Seal applied.

Though officially part of the rudder controls, the plastic rudder cable guides were drilled. They were then attached to the forward tunnel.

This shows the elevator idler arm in final configuration with pushrods attached. The space was tight for my hands when inserting the bolt, rod end bearing and washers. A rare earth magnet on the bolt end and washer pliers greatly helped during assembly.

This jig was created to align the neutral position of the elevators at the bellcrank position. The final configuration was established with later posts on Empennage Attachment.

Posted in: RV-10 Build Project, Section 39, Control System

Rudder Pedals and Brake System (3)

05-Jul-2020 10:09 ⋅ Leave a Comment ⋅ Mark

Final connections for brake lines were completed this week.

The parking brake connected with heavy duty stainless lines to the master cylinders on the pilot’s pedals. The Bonaco coated, flexible lines were then run through the center lever bracket to the copilot side.

Here are details about the cable lace and rescue tape applied to hold the lines in place.

MISCELLANEOUS

In researching the fuel level sensors, many recommendations were made to replace the regular gasket material with Viton. Here are pictures of the McFarlane product to be installed at a later date. In addition, I also ordered Viton Fluoroelastomer O-rings for the #8 screws which hold the fuel sensor base plate onto the wing tanks. These were obtained from McMaster part number 9464K12.