Roee Kalinsky's RV-7A Project

2007.05.17: (6.0) [this entry covers the past few days] The scoops themselves are molded plastic (ABS, I'm guessing).  I cleaned them up by filing down the burrs and seams and slag.  Then, located and marked their locations on the side skins, making them fit the pre-cut holes as well as possible.  I decided to install my scoops with both adhesive (probably fuel tank sealant) and 1/8" 120° countersunk blind rivets (CS4-4).  Located and drilled rivet holes in the skins, then match-drilled the flanges of the plastic scoops.

Match-drilled and cut some 0.016" aluminum strips that'll go behind the scoops' flanges.  This is so the soft plastic flanges will be sandwiched between aluminum on both sides (the side skins and the 0.016" strips) and will not be damaged by the rivets.

Dimpled the skins and countersunk the scoops for 1/8" 120° countersunk blind rivets (CS4-4).

2008.06.26: (0.0) The eyeball vents that Van's ships in the kit feel like they were made by Fisher-Price.  Van's even acknowledges in the builder's manual that when closed they still leak badly, and they advise a cheesey fix by globbing RTV around the edges of the door...  No thanks.  I bought a pair of machined aluminum vents from SteinAir, p/n AV-1.25C.  These are definitely pricey at $90 a pop, but they're definitely high quality.

These vents from SteinAir mount into a 2" round hole.  They don't have a built-in flange like the plastic ones from Van's.  So I made the flanges from 0.062" 2024-T3 aluminum.  I then mounted that in the same manner as Van's suggested mounting, but I altered the geometry slightly, and added another screw to the instrument panel for a more secure installation.

2009.11.13: (0.0) Trial-fitted the ducting between the NACA scoop and the eyeball vent.  This is 2" diameter ducting supplied by Van's, which appears to be similar to CAT ducting (standard CAT/CEET/SCAT/SCEET ducting should work just as well, but I haven't tried it).  A straight duct length of 15 inches (17 spiral rings) is about right.  Note that the ducting has to curve around the bulkhead and subpanel.  In order to secure it a little bit better and prevent vibration and chafing, I added a nutplate to the bulkhead to secure the ducting there with a cushioned clamp.  An MS21919-34 clamp works well for this.  Note that this is a 2-1/8" diameter clamp, which holds the 2" ducting securely without crushing it (selected empirically by trial and error with different size clamps from 2" to 2-1/4").