Dave’s RV-7A Building Log

I had a good idea concerning the labels. I decided to try sticking them to something other than the panel. The fuel selector needs to be labeled with left/right/off, so I tried applying some labels to it. The surface is much smoother than the panel, as I just painted it with some flat black Rustoleum. The labels turned out much better. None of them sticked completely, but I verified that I’m using the correct amount of spray glue and that the rough texture of the panel is the source of most of my problems. Now the question is what to do about it.

I also spent a few minutes finishing up some wiring tasks.

November was a crazy month in Seattle with record high and low temps, and a new all-time high monthly total for rain. We also set a record for most hours worked on the plane in one month, mostly due to all Julie’s help with the wing riveting. Also shows that I’m eager to get it finished up.

An evening of little tasks to knock down the to-do list. I was going to finish up the sniffle valve install, but don’t have the right sized adle clamp. I’ll have to wait for my recent Aircraft Spruce order to arrive. The routing of the tube looks good, though. I also debated about how to better secure the crankcase breather tube. I think an adle clamp on the engine mount would be best, which means moving the fuel pump overflow. I might switch that over to adle clamps as well. It seems like I’m going adle clamp crazy, but I’d rather have everything secure than flopping around.

I picked a task at random and decided to drill the weep hole at the bottom of the filtered airbox snorkel. The instructions call for a 1/16″ hole for water to drain out. I was too nervous to drill it before, but had no problems today. I took out the filter, so I could stick the shop vac down there and catch any debris while drilling. Done.

Next was some wiring. I removed several wires from the EMS harness that I don’t need. I can always add them back later. Easy task. Next was routing the coax for the capacitive fuel converters out the side of the plane. I just drilled a hole and put in a snap bushing near where the vent tube exits. Also easy.

It seems like there’s an endless number of little tasks left. If I keep knocking them down, they’ll eventually all get done.

Got a ton of little stuff done today. I put connectors on the serial wires from the P-mag and made a patch cord to the computer in the house. I ran the EICAD software on the PC and was able to connect to the P-mag. I thought the P-mag had to be in setup mode, but it actually has to be in run mode to communicate. Various parameters can be set via the interface including advance angle, run mode starting delay, tach pulses per revolution, and a few others. According to the web site, live manifold pressure, RPM, and advance angle can also be read and the timing can be set, but that doesn’t seem to be available in the current EICAD software.

I finished up the EGT (exhaust gas temp) and CHT (cylinder head temp) probes and crimped on connectors for the fuel flow sensor. I’m pretty sure that’s the last of the sensor wiring. In fact all of the wiring is almost finished. Just a couple more small tasks.

I completed installing the eyeballs for the control cables. The tiny screws are a bit of a hassle, but not impossible.

The last task for the day was to install the sniffle valve. I’ve been putting it off because I though preservative oil would pour out of the engine. After thinking about it some more, I realized there shouldn’t be much oil in there. Maybe just a light spray. I removed the plug and sure enough just a few drops came out. I put in the special Piper sniffle valve that has a 90 degree bend. The normal valve would interfere with the exhaust pipe. I attached a short section of rubber hose and then transitioned to soft aluminum tubing. Ran out of time before securing the tubing to the engine mount.

I checked into the graphics shop with the big UV-curable inkjet printer. Unfortunately, they can’t print white. The best they can offer is white vinyl lettering. I’m not sure that would look very good or be very durable. I’ll have to look into it, though.

After some more advice from Frank at Pulsar, I tried another round of labels. I’m getting really good at all of the steps leading up to applying them to the panel. Out of 5 labels, I only messed up one along the way. However, I still was unable to get a single word of any of the labels to stick successfully. I tried more glue and less glue. The spray glue just doesn’t seem sticky to me. I’m letting it dry and even hit it with the heat gun on low for a few minutes. I’m going to buy a new can of spray glue tomorrow. I know it can work, because I have 3 labels that worked great. I’ve had quite a string of bad luck lately, though.

After that frustrating experience, I did a few random things on the plane to make some small progress. It’s been super cold here in Seattle, so I put a heat lamp on the forward skin hatches overnight to help the Proseal cure. That worked well. I removed the hatches and peeled off the Glad wrap. The homemade seals look good.

Julie helped me dimple the last few holes in the forward skin with the C-frame dimpler. I think that’s the last time I’ll need that thing. I also did the final install on one of the control cable firewall eyeballs.

Julie graciously agreed to help me move the wings down to the airport today. We probably could have made a pick-up truck work, but renting a 16′ covered truck made it much easier. We also moved down some miscellaneous stuff like the seats, interior, and some covers. It was a two step process to get the wings in and out of the truck. We put the wings onto saw horses one at a time and then moved the cradle. Leo rode shotgun.

I took pictures of the wing ends just in case I need them later.

Later in the day, I messed around with the EGT/CHT probe connectors some more, soldering the connectors per the instructions from AFS. I also finished the ignition wires for the right bottom spark plugs. All the ignition wires are now hooked up.

More supplies arrived from Pulsar, so I tried some more labels. The white overlay did a much better job of sticking only to the toner, but I still couldn’t get any of the labels to stick reliably to the panel. Very, very frustrating. I want this process to work, but don’t want to waste any more time on it. One of the guys in the EAA chapter suggested a shop in Redmond that can print directly on any flat surface with a UV-curable ink. Looks like it might be a better approach. I’ll call them Monday to get the details.

I called up Geoff Sharples to come over for one last Technical Counselor visit. He checked out the wings thoroughly and looked over the engine area a bit. Thumbs up all around.

I’d like to get the wiring completely finished (at least until the wings are mounted), so I’ve been concentrating on that lately. I finished the ignition wires for the bottom left plugs and attached connectors for the EGT and CHT probes.

I thought the wings were ready to go, but remembered one more thing I needed to do. Proseal on the access covers since I had to remove them for the service bulletin. I got everything prepped and cleaned including a few other items that have been waiting for Proseal. It was a very easy session.

I prosealed the NACA intakes for cabin air in place and held them there with Duct tape until it set. Some people use rivets as well. After struggling to pry off the fuel tank access covers, I think Proseal is more than enough to hold them. If they ever fall off, I’ll use rivets.

I made some seals for the forward deck hatches. I put some sticky plastic wrap on the covers and scuffed the skins. The idea is that the Proseal will stick to just one side and make a homemade rubbery seal. Before all of that, I had to remove the blue plastic, deburr, and dimple the skin. So sad (not) that it’s the last skin that will need to be prepped.

I also squirted some Proseal into the gap at the bottom of the external steps. Probably wasn’t really needed, but might as well.

I tried another round of panel labels. Zero successful.

I installed the OAT sensor in the left wing in the first full-sized bay. I would have put it further out, but the harness from AFS had a bit of a short OAT wire and I didn’t want to string another.

I also finished installing the flap sensor and attached wires to it. I moved the flap weldment up and down a few times with the motor and it seems like it’ll work well.

EAA 1440 meeting last night. I was elected VP for another year.

Back to the task of getting the wings finished up. I mounted the little circuit board for the pitot tube to one of the wing ribs. This would have been much easier a few weeks ago before the bottom skins were riveted. I bent the very end of the copper tubing from the pitot toward the wing root. I was still able to get the pitot tube in and out through the mast, but the bend made the transition to the plastic tubing easier. One a tip from DanC I used some silicone tubing from Spruce to connect the copper to the plastic. Seems like a very tight connection even without any clamps.

I used an adle clamp to hold the plastic tubing away from the bellcrank.

Got home early after the yearly parent/teacher conference. I did another session with the labels and had one successful out of 3. Not bad. After thinking about it overnight, I decided that the fuser (a.k.a. laminating machine) is getting too hot. That’s why the first session worked well yesterday and the next two didn’t. The lettering is sticking too well to the mylar. I’m going to keep chipping away at the labels in short sessions every day. Hopefully after a week they’ll be done.

I worked on the wing tips some more. I sanded a couple spots down a bit more for a better fit and drilled out to #30. I cleaned up the notch of the cut out for the ailerons. I also fitted and drilled the ribs that reinforce and close off the trailing edge of the tips. The last task was to drill out the holes in the skins to #28, deburr, and dimple. Just a couple more things to do on the wings and I can move them down to the hangar.

And one of those last things is installing the pitot tube. Unfortunately, the Gretz pitot tube does not fit into the Gretz pitot mount. Not a big deal. The instructions suggest grinding it down with a Scotchbrite wheel. The pitot tube is such an odd shape that it’s difficult to get all surface in contact with the wheel. I had to remove the safety cover. Once I finally got them fitting together, I discovered the screw holes don’t line up. Come on. These two parts came from the same guy and they don’t even come close to fitting together. Time to haul out the Dremel.

I also took another look at the fuel flow sensor. I think using a 45 or 90 degree fitting on the outlet will solve the fit problems. I’d prefer the 45, so I’ll try that first. Almost time for another Spruce order.