The big day! Dolly and I have been building this RV-7 for almost two years. Each has had a significant milepost. In 2015 it was the test fitting of the wings to the fuselage. This year it’s the airport move.
Dalton Airport (3DA) is a small private/public airport located on one of the main streets in Flushing, Michigan. Pole barn hangars with electric doors line the sides of both the sod and the 3500′ hard surface runway. EAA Chapter 77 owns a cavernous main hangar and one of the smaller hangars where I rent space. That’s where we are going.
The move was blissfully uneventful. I had arranged for a tilt-bed automobile hauler from Norm’s Towing in Montrose. Norm showed up on time; the plane was winched up the ramp and strapped down. It was threatening rain, but we were prepared with a tarp. Twelve miles and $100 later we were ensconced in our new home.
Please forgive the misleading headline of this post. “Installing a motor mount and adding landing gear legs, wheels and brakes” just doesn’t work as a title.
Master and starter solenoids, the battery box and cabin heat valve were installed on the firewall. Then the motor mount was added.
Four ratchet straps were hung over a pole barn truss to lift the fuselage.
Notice the recessed cover had been riveted into the center of the firewall.
After a little excess powder coating was removed from the gear legs they slipped nicely into the mount tubes. The retainer holes were reamed to 0.3115 inches for the close fit bolts which slid in with taps from a plastic hammer. Nuts were torqued to 190 in-lb, including 50 in-lb turning drag.
Beringer brake caliper mount holes were drilled to the axles and reamed to 0.3115″. Hubs/tires were mounted with brake discs safetied on the hubs with 0.40″ wire.
There was almost as much masking, sanding and fitting of the rear window as for the tip-up canopy. The rear window fits over the top of the roll bar and under the fuselage skin. The sides and aft edge of the window are trimmed to about an inch beyond the edge of the skin.
The front edge of the window is cut and sanded to match the aft end of the closed canopy. With the tip-up closed and the window removed, a fine line is drawn across the roll bar just behind the tip-up to guide glue application.
Gluing was done after moving the project to the Dalton Airport. SIKA glue application was similar to that used for the tip-up canopy. The rear window was braced against the clecoed skin using thin battens and a board resting on the baggage compartment top longerons.
The rear skin was riveted, and the Inner and outer protective plastic film replaced with food wrap on the outside of the window.
This post is not meant to be a step by step guide as to gluing the window. Adjusting the window placement during gluing is difficult. There were many opening and closings of the tip-up during the process.
July 12, 2016 through October 8, 2016
Vans calls constructing the canopy, whether tip-up or slider, one of the most challenging aspects of the build. Vans is always right.
Our “tipper” began with drilling the HDPE blocks that are bolted to the fuselage and serve as hinge supports for the front of the canopy. These blocks support retractable pins that hold the front of the canopy in place. The retraction mechanism is controlled by a tee handle that may be pulled to release the canopy. Builders who plan on doing aerobatics while wearing parachutes will place the tee handle on the instrument panel. Not having those aspirations, our handle is on the sub-panel where it is accessible on the ground by first opening the canopy.
The standard Vans RV Canopy Latch Handle protrudes from the fuselage out into the air stream. I purchased a JDAir system that is flush to the fuselage, sitting in rectangular slots cut in the skin. The mechanism consists of a latch that is pushed in to release a handle that pops out of the skin. The handle can then be pulled to open the canopy.
The handles are fitted and bolted to doublers that will later be riveted to the skin. Then, a metal template is cut and fitted to the handles. The template shown above best positions the slot pattern that is transferred to the skin.
The slots are cut, and the latch mechanism is bolted to the doublers and riveted to the skin. The above photo shows the completed flush latch handles at a later stage of the build.
This last photo, taken from the JDAir website, shows the cockpit side of the handles.
Dolly’s 20 gal compressor failed in July. I replaced it with this oil-less 150 psi unit from Harbor Freight. It works as advertised. I learned however that a lower-pressure higher-volume pump might have been a better choice. Our air tools don’t need pressures above 60 psi, and this pump can’t keep up with our die grinder or finger sander. It also runs longer reaching it’s non-adjustable cutoff pressure of 150 psi. Fortunately it fits under the weather cover built for it’s horizontal tank predecessor.
For the RV-7 we purchased an ACK-04 ELT. It transmits on 406 as well as 121.5 MHz. and connects to Garmin G3X providing NEMA 0183 GPS position data. The installation manual requires the ELT be mounted parallel to the aircraft forward axis; and also recommends it be near the rear of the aircraft. Unfortunately a rear mount would make the transmitter inaccessible to CFIT survivors.
I have chosen to mount the ELT on the tunnel cover forward of the seats. While this may increase the risk of ELT damage in a CFIT, an impact of that magnitude would likely eliminate survivors.
Another recommendation is that the mounting provide deflection stiffness so spatial movement is no more than 0.1 inch under a pressure of 100 pounds. The pictured reinforcing channels do that.
The electric fuel boost pump is mounted on a separate section of tunnel cover. An additional cover over the pump & filter will separate them from the ELT.
The Garmin autopilot pitch servo is furnished with a mounting plate and specific instructions for installation in a Vans RV-7. The plate becomes riveted to the center floor rib behind the baggage bulkhead. The servo moves the elevator push-rod via its connection to the bellcrank.
Care is given to adjusting the length of the servo to pitch bellcrank connecting rod so that no over-center lockup can occur.
Wires from the db15 socket connect the servo to both the instrument panel autopilot controller and to the pitch trim servo located in the left elevator. Torque sensors in the pictured servo generate signals fed to the pitch trim servo.
The flap position sensor is a Ray Allen POS-12. The long arm slides in and out of the body changing the electrical resistance of the unit. A linkage to the motor driven flap actuating arm controls its position. The flap position may be displayed on the G3X screens.