More Reassembly and New Tailwheel Fork

I finished adjusting the flap pushrods and final torqued them.  I had to open up the holes a bit more to make room for the bolt head when the flap is just about fully up.  I taped the ailerons to the wingtips and the elevator in the neutral position to use as a reference and then adjusted the flap pushrods so that the flaps align with the ailerons.  Finally, I lubricated these rod end bearings.

I swapped out my tailwheel fork for the one from JDAir.  The person I spoke with there claimed I would save about a pound over the Bell fork I had, but the savings was just over 1/2 pound.  I’m still glad I made the switch, but disappointed that the savings wasn’t what they claimed.

I installed the baggage wall and then taped up a ziploc bag as the temporary holder for my registration, airworthiness certificate and phase 1 operating limitations.

With the flaps adjusted, I could now install the flap covers.

Finally, I vacuumed out the inside of the plane and installed all of the forward interior components.  I’m not going to bother installing the interior pieces in the baggage area for phase one (except for the final weight and balance).

Continued Reassembly

My buddy Andre stopped by the hangar this morning to help me remove the canopy one last time.

I inadvertently used the wrong weatherstripping on the flange at the forward edge.  It was too thick, and the canopy skin kept catching on it and was tearing it off.  After Jenn and I reinstalled the canopy the last time, I found the correct weatherstripping in a box, so I decided to swap it before first flight.  Unfortunately, after Andre and I removed the canopy, I could no longer find it, so I have some new weatherstripping on order.

I didn’t get any pictures of it, but I lubricated all of the bearings on the plane.  There are nearly three dozen of them, and many are exposed to the elements.  I’m using a product called DriSlide.  It wicks into the bearing and dries, leaving behind a film of molybdenum disulfide.  This film is extremely slippery, but because it’s dry, it doesn’t attract dust or dirt, is highly resistant to water, and prevents rust and corrosion.  I’m also using it on the sliding pins in the brake calipers to keep dirt from sticking to them.

After wrapping that up, I installed the wingtips.  I used some DriSlide on the hinge pins and they slipped in effortlessly.

I reinstalled the alternator with the washers in front of the pivot shaft.  I checked the alignment, and it looks perfect.  I adjusted the tension so that I could turn the alternator pulley with 13 ft-lbs of torque (with the pulley slipping on the belt), but couldn’t turn the pulley with 11 ft-lbs of torque.

After fully inspecting all of the controls under the seats, I installed the forward center section cover, fuel pump cover, spar covers, seat pans and tunnel cover and screwed everything down.

The DAR mentioned that he doesn’t like Van’s design for the flap pushrod attachment since the rod could come off if the rod end fails.  Every other rod end on the plane is either captured by the surrounding attach point or has an AN970 washer to keep the rod end together in case of bearing failure.  The failure of a rod end can be a catastrophic failure since a split flap condition can cause a violent rolling motion.  Since full flaps are usually used on final approach when low and slow, a failure here could be fatal.  By switching to a regular rod end from the ball joint linkage supplied in the kit, you can prevent the joint from ever coming apart.

Fortunately, my friend Greg had already warned me that the DAR would like the see these parts upgraded, so I had the parts in hand.  I also upgraded the pushrod from the one I made to the one sold by Avery Tools.  I still need to adjust the pushrod length to get the flaps back into alignment with the ailerons, but I’m much happier with this arrangement.

Since my CG ended up farther back than I was hoping, I’ve been looking for ways to move it forward.  I purchased the Bell tailwheel fork a long time ago since I really dislike the Van’s design.  I didn’t realize at the time how much heavier it was though.  While researching other options, I found that the tailwheel fork sold by JDAir was even lighter than Van’s.  I haven’t measured for myself yet, but they told me that I should save about 1 pound from the Bell fork.  This doesn’t sound like much, but with an arm of over 249″, this change alone will move the CG forward by over 0.15″.  The fork comes plain or powder coated in either gloss white or gloss black, but I previously powder coated all of my tailwheel components in matte black, so I ordered it plain so that I could match the finish.  I stopped by the TechShop earlier today and smoothed out all of the edges and then sandblasted the areas that will be powder coated.  That produces a nice textured finish that the powder coat will stick to nicely.

I applied the powder coat and then baked it in the oven for about 20 minutes at 350º.

Airworthy!

I met with the DAR this morning.  After he inspected the plane, we went over the paperwork I submitted and then reviewed my operating limitations.  Finally, he issued my airworthiness certificate, so the plane is officially airworthy.  We spent a little time afterward discussing my preparations for flight testing and covering the test plan for my initial flight.

My airframe logbook also gets an entry stating the plane is airworthy.

With the final inspection done, I started buttoning up the plane to get it ready for flight.  First up, I installed the wing inspection panels (all but one which I’ll discuss below).

I then moved on and installed the wing root fairings.  The adhesive I applied the other day seems to have worked out well.

Before installing the last wing inspection panel, I needed to install the aileron servo stop.  I couldn’t get the bracket in place without enlarging the center slot a bit.  After ensuring it would fit, I shot a fresh coat of paint on to keep this from rusting.

Finally, I installed it on the servo.  Slipping it behind the arm and under the safety wire is a little tricky and it will only go one way.  I installed an AN960-10 washer between the bracket and the servo under each mounting screw to space the bracket away from the servo by the thickness of the servo mounting bracket.

Update: I subsequently caught that the safety wire on the lower bracket bolt was reversed.  This is another issue that I’m surprised wasn’t caught at the builder inspection party.  There wasn’t much room to work in there, but I managed to get the wire reversed.

While doing a thorough pre-flight before buttoning up each panel, I found this missing bolt (you can see the bolt over on the right).  I had removed this a long time ago because I was using it to hold an adel clamp for the servo wires.  When I rerouted the wires, it never occurred to me to check this.  I’m really surprised that this wasn’t found during my builder inspection party.  There were a couple of guys that were doing a pretty thorough inspection with mirrors and flashlights.  Regardless, I had always planned on doing a complete control integrity check from end to end, so I wouldn’t have made it to first flight without catching this.

I installed a new bolt (and way too much torque seal because I couldn’t see it well).

With nothing left to do on top of the engine, I installed the plenum for the last time before first flight.

I also installed the spinner.

Since I need to shift the alternator back by about 3/32″, I pulled the mounting bolts and removed it.

I’ll need to file off the aft end of the pivot shaft (not visible here), I taped up the alternator to ensure no metal filings make their way inside.

This shaft is about 2.992″ long, and I need to take about 0.094 off the right end of this shaft.

I can then use one AN960-616 and one AN960-616L washer to make up the difference.

After grinding down the shaft, you can see that I have the same length when I now include the washers.  I’ll reinstall the alternator tomorrow and re-tension the belt.  This ended up being way easier than I expected.

More Work on Cowling

I ground down the fiberglass filler I applied a couple of days ago.  After a coat of primer, you won’t even be able to tell it was damaged.

I started prepping the cowling for paint by masking off the inside so I don’t get overspray on the white paint, but I ran out of tape.  I’ll pick up some more tape tomorrow so I can wrap this up.

Alternator Pulley Alignment and Wing Root Fairing Seals

I spoke with AeroSport Power today about the alternator pulley misalignment.  Since I’ve never adjusted the alternator since receiving the engine from them, it must have been misaligned from the beginning.  They wanted me to check and make sure the flywheel tracked true, so I used a piece of stainless tubing against the back of the flywheel while rotating the prop.  I also aligned the tubing to the tip of the prop and checked the blade-to-blade tracking.  In both cases, everything looks perfect.

I tried taking pictures from a couple of angles to capture the misalignment, but the perspective of the camera makes it really hard to see.

In the end, I determined that the pulley is 3/32″ forward of the flywheel.  After speaking with AeroSport again, they determined I’m going to have to shift the alternator back by adjusting the spacers in front of and behind the pivot shaft on the alternator.

Afterward, I decided to glue on the wing root fairing seals.  I used 3M Super Weatherstrip Adhesive to glue these on.

Repaired Cowl Damage From Spinner Screws

When I did the first taxi test, I had incorrectly installed the screws that tie the conical section of the spinner backplate halves together.  I forgot that there was a note in the installation manual that the screw heads needed to be on the aft side to provide clearance between the spinner and cowl. I installed the nut on the aft side, and the ends of the screws cut into the cowl flange a bit.  I ground all of the damaged material out of the cowl and then applied a thin layer of raw epoxy to coat the inside of the cut.  In addition to reversing the screws, I switched from AN515 to AN525 screws to further reduce the height of the head.

My flox is down at the hangar, so I cut up a small piece of fiberglass cloth into tiny pieces and mixed it into some epoxy.  I filled the gap with this and left it a little proud of the surface.  I’ll grind this flat once the epoxy cures.

While the epoxy was curing, I sanded both cowl air inlet on the top and bottom.  The cowl is very close to getting the first coat of primer.

Calibrated Fuel Tank Senders

I calibrated the fuel tank senders today.  I’m using the Princeton two-point capacitive senders which are pretty straightforward to calibrate.  Here are the basic steps:

  1. Empty the tank (I had already done this when determining unusable fuel for the W&B).
  2. Power on the sender.
  3. Hit the set button to set the empty point.
  4. Fill the tank.
  5. Hit the set button again to set the full point.

The sender then puts out the full 0-5V range from empty to full.  This is much better than the Dynon capacitive senders which can’t be calibrated and generally put out a small fraction of that voltage range across the whole tank capacity.  The Princeton senders solve the dynamic range problem, but the voltage still doesn’t necessarily follow the fuel volume in a linear way.  The SkyView system solves that by including a separate calibration mechanism where you add fuel 2 gallons at a time.  Each time fuel is added, a button is hit on the SkyView to correlate that particular voltage reading from the sender with that fuel volume.  Unfortunately, this means that I need to start over with an empty tank to do the SkyView calibration.  Since I don’t have any interest in draining that much fuel out of the tanks, I’ll have to wait until I’m flying and can burn down the fuel.

I did this for the left tank by pouring fuel from gas cans into the tank, but it was very time consuming and I ended up spilling some gas.  Since I hadn’t run the engine in a month, I taxied the plane down to the pump to calibrate the right tank.  I used that as an opportunity to break in the brakes a bit more too.

Using the capacitive probes with the Princeton senders should result in a nearly perfectly linear fuel gauge reading across the entire tank capacity.  This is quite a bit better than the resistive senders which read empty when there is still a fair amount of fuel in the tanks and reads full well below the full capacity of the tank…