Dave’s RV-7A Building Log

Adele had a soccer game tonight, so I didn’t get too much done. I shortened the bushings on the fuel selector a little bit. They ended up being 22/32″ long, which looks about right. I also grinded off the pointer on the handle. The handle itself becomes the pointer. It would be very easy to make a nicer handle for the fuel selector.

The ELT and static ports I ordered from SafeAir arrived. Installing the ELT looks pretty straight forward. I just need to find a place to put it. I’m thinking underneath the baggage floor as Dan and others have done.

I previously ordered static ports from Cleaveland, but didn’t like the barbed fittings for the tubing. A few people have lately reported that the tubing splits when forced over those barbs. SafeAir makes a slick static port system, but it costs $80. Instead I ordered their static ports for $25. By buying a couple of Nylo-seal fittings from Aircraft Spruce, I should be able to make use of most of the Vans static kit I already purchased with the SafeAir static ports.

I installed the fuel vents in the floor of the forward fuselage. I contemplated starting the fuel vent runs, but decided to do something easier.

I pulled out the parts for the fuel selector and started assembling them. A few builders have mentioned on their sites that the bushings detailed in the plans are not long enough, so I made mine 1/8″ longer. That may have been too long. I’m not sure if the fuel selector itself needs to rest against the plate. I’ll probably shorten them 1/16″. I also moved the plug and installed the fittings as detailed in the plans with some Loctite thread sealant. I installed a T in the bottom of the selector, since it’s needed for the fuel pump/filter.

I noticed that Walter Tondu powder coated his steps. I decided to try that as well. Express Finishing in Redmond did a terrific job with it. I picked a color they shoot often, matte black, and was able to get the steps back in one day. I think they usually handle much larger jobs, but they didn’t mind including my parts with another customer’s batch. Both parts cost $30. Seems reasonable to me for a coating that should be very tough. And they look great.

I ordered a better tube bender today. I’m going to wait until it arrives before tackling the fuel pump again.

I looked around for something simple to do. I decided to make the fuel vent fittings. They are basically modified fittings. I used the Scotch-brite wheel to remove the threads, cut off the end at an angle with the band saw, cleaned up the cut on the belt sander, and then did a final polish with the Scotch-brite wheel. I picked up some faucet aerators with screens at the Home Depot a few days ago. I was able to use just one screen to cover both openings. I cut the screen to shape with scissors and then used JB Weld to attach them after cleaning everything with MEK. They turned out pretty nice.

I riveted platenuts on all of the various covers for the fuel pump. There are about a dozen of them.

The next step was to fit the filter and pump to the base. As others have pointed out, one fitting on the pump needs to be turned in order to not interfere with the filter. That part wasn’t difficult, but I spent an hour wrangling with the tubing to get it to fit after moving the fitting. And it still wasn’t successful. I ended up crimping the tubing, so I’ll have to start over with a new piece. Frustrating.

I tried using the tubing bender. It works pretty good, but I can’t seem to get a nice smooth 180 degree bend. My bender only does 90 degrees and can’t seem to do two 90 degree bends right next to each other. Time to do some research on the net about tube bending.

Another weird thing is that after removing that tube, I noticed that one of the fittings on the pump was really loose. It’s a brass fitting that connects to a plastic part with an O-ring inside. The fitting was less than hand tight. I’m sure I didn’t loosen it, because I had a wrench on it when I was removing the tubing. I tightened up the fitting by hand and gave it another quarter turn with a wrench. I don’t want fuel leaking out of this thing in the future.

Of course I had to fire up the pump. I briefly touched the leads to a 12v drill battery that I have. I only ran it for a second, as the instructions say not to run it without fuel running through it–probably for cooling. The thing makes an awesome hum, and torques quite a bit when it starts up. Impressive.

Worked more on fitting the fuel pump covers. It’s really nice (not) that all of the fuel pump covers are attached with #6 screws instead of the #8 screws that are used throughout the entire rest of the plane. I don’t have a platenut jig for #6 or the right drill bits. I ended up using a 9/64″ drill from my regular drill bits.

I basically fitted all of the covers together and drilled the required holes. I had a heck of a time getting the pump platform fitted between the floor stiffeners. It was about 1/8″ too wide. I bent the two sides of the platforum inward and was able to jam it in there.

I took everything apart, drilled holes for the platenuts, and deburred all of the holes. I also cut off the front of the fuel selector mounting plate. The forward triangle is used for manual elevator trim, but I’m using electric.

While I was at the hardware store, I picked up a stubby 1 point Phillips screwdriver. I used that to attach the servo for the electric aileron trim. That’s about all I can do on that part until I get the control column mounts installed.

Started working on fuel pump covers by modifying the existing forward cabin covers. I followed that up with lots of deburring of the covers.

I figured out a way to drill the holes in the seat rib for the electric aileron trim servo. I have a left over drill chuck from when I put a Jacobs chuck on the air drill. I put the 9/64″ drill bit in the chuck and then just hand turned it. Since the holes were already drilled to #30, it wasn’t hard to enlarge the hole a little bit. After deburring, I started to attach the servo but couldn’t find my small Phillips screwdriver.

I messed around with a few other things in the cabin, but spent most of the evening on house projects.

It seems like the electric aileron trim is taking forever, but I’ve just been chipping away at it over several sessions for an hour or so each day. Today I installed platenuts on the main plate. The instructions call for countersinking the bracket and plastic block for a #10 screw, but I decided to dimple the bracket and countersink the block for slightly better strength. I assembled everything, and it worked out fine. I also attached the servo to the crank arm via the little connector parts. I had a hard time with the clevis pin at the servo end. The plans call for a washer under the cotter pin, but I couldn’t get it to fit. I wasn’t comfortable leaving the washer out. I was worried the cotter pin would eat into the soft aluminum connector part. I ended up stealing a thin 960-8L washer from the empennage trim parts, which worked out perfectly.

I had a little more time, so I attempted to mount the whole thing in the fuselage. One of the platenuts was off-center from the middle of the hole, making it darn near impossible to get a screw into it. I don’t know how that happens, but it’s frustrating. After I finally got the bracket mounted, I marked some holes that will hold the servo to the seat rib web. Of course I don’t have a #28 angle drill bit that’s needed to drill a hole for the #6 screws. I drilled the holes out to #21, and I’m currently trying to figure out how to get a regular 9/64″ drill bit to work. I used to have a regular chucking angle drill, but I can’t find it anymore.

It would have been a lot easier to install this thing before the center section was riveted together.

Still keeping busy with other things lately, but managed to work on the electric aileron trim a little more. I primed a few of the parts. I also cut the tube of the crank arm, drilled it for the cotter pin, and assembled it in the plastic block.