Fairleads and some filler work

Found one fabric attach plate where we had not yet added filler to smooth over some of the rivet heads, so some lightweight filler was added, and then sanded smooth once dried.

Filler added to fabric attach plate on left wing

Also, 6 plastic fairleads were installed in the tail section which are guides for the rudder and elevator cables.  Had some difficulty installing the metal clips at first, but then discovered a trick that helped which was to use a C-Clamp to hold the metal clip right against plastic fairlead, and then pop the clip in place with a small screwdriver.  I learned my lesson after fighting with the first few clips while just trying to use a pair of needle-nose pliers.  I was able to get them on with the pliers, but it was a fight.  The trick with the C-clamp seemed to work well, though.  Hours: 1.5

Plastic fairlead installed with metal retaining clip

Trim Servo cont.

Today we made some adjustments to the connection between the servo motor and the trim tab to get it working with the right range of motion. We get about 30 degrees of motion in one direction, and 40 in the other which is plenty.  The stainless steel connecting rod was shortened, and we drilled a new 1/8 hole in the connecting tab at a spot that was a little lower than the original hole to get more motion.  We also reshaped the connecting tab  to eliminate any interference with the attaching clevis. Below was a test of the servo motor using a small 9V battery.  Hours: 2.0

Trim Servo Mount Plate

The CCC-44 rivets arrived from Aircraft Spruce.  Before riveting the part in place, four nutplates were installed that matched the hole pattern in the Ray Allen trim servo.  Once completed the mount plate was riveted in place.  A temporary rod was installed to mount the the trim tab and a 9V battery was used to check the movement of the servo.  We still need to calculate the correct attach point of the servo clevis pin to get the range of motion we need, but it was nice seeing the time tab move.

Trim Servo Mount Plate Installed

We also started looking at possible mounting positions for the transponder and ADS/B antenna below the baggage area.  We have a couple of ideas we are exploring.  Hours: 1.5

Pitot and Trim

The new pitot tube stalk was completed.  The base that Ed had welded on needed to be cut down to the correct size.  Four edge nutplates were installed on the base.  Then the length of the part needed to be cut down.  All surfaces were then deburred and the four holes needed to mount the Garmin Pitot tube were drilled.

The biggest benefit was that we cut the weight of the part by 1/2.  The original mount weighed in at 5.7 oz and the new part weighed in  at 2.1 oz.  

2.1oz (new) vs. 5.7 oz (old)

Pitot Tube complete

Started working on the trim servo mount and found that the mounting plate needed to be raised up about 0.09" to be flush with the fabric surface.  Two spacers were made from 0.09" aluminum stock.   Everything is cleco'd in place awaiting riveting.  CCC-44 rivets will need to be ordered.  Hours: 2.5

Pitot tube modifications

We noticed that once mounted, the pitot mount is not angled straight down. We're making two changes, one is to fix the angle, and the other is to change from a steel to an aluminum mount to save weight.  Michael determined the correct angle and positioned the mounting plate correctly on new aluminum material we purchased.  Then I welded it to secure it in place (see picture below).  Hours: 1.0

New pitot mount welded

Leading Edge Cuff and Trim Servo

To finish off the leading edge cuff, the cuff kit included epoxy end pieces.  We plan to affix them to the windshield/wing root fairing as shown in the picture.

Wing Cuff at Wing Root

Moved on to the Ray Allen trim servo mounting.  In order to align the servo arm with the trim tab arm it looks like a mount plate will be needed.  A plate was made out of 0.032" aluminum and cleco's in place using the factory weld attach points.  Hours: 1

Aligning the servo arm

Servo Attach Mounting Plate

Pressure test of header tank

Ran a pressure test on the newly minted header tank.  I did this by first capping off all inlets/outlets except for one, and attaching a schrader valve plus low-pressure gauge to the single open port.  I pressurized the tank to 5 PSI, and noticed a slight drop in pressure over time.  I then got out a spray bottle with soapy water and sprayed it all around the welds and fittings to find the leak.  Actually found two issues.  One was a small pinhole leak around one of the welds for a bung on the side of the tank.  The second was a tiny leak along an inner seam where the V-bracket was welded to the tank.

I removed all the fittings, then ground down some of the original weld material at the leak locations. I cleaned the surfaces and touched up those spots with the TIG machine by remelting the area and adding a little more aluminum filler material. The V-bracket inner seam was difficult to weld because of the corner that was formed by all the angles, so I changed to a smaller TIG torch and electrode prior to rewelding to get better access into the corner.

Once it was all touched up, I re-ran the pressure test.  I didn't see any drop in pressure, and I also gave it the soapy water treatment to see if I could find any bubbles.  Everything looks good.  I'm going to leave it pressurized for a day just to make sure there are no other slight leaks that I haven't found, but so far it's looking good. Hours: 2.5

Adding air to the tank to pressurize it

Tank with all fittings attached during pressure test

Wing Cuff and Pitot Tube

Completed the modifications to the outboard left wing cuff and taped it in place for later installation.

Left Outboard Leading Edge Wing Cuff

Also installed the pitot tube and AOA tube into the wing.  This involved drilling a 1/4" hole into the rear spar tube.  The hole was drilling into the Hysol epoxy where one of the wing ribs was installed.  Adel clamps were used to to secure the tubes to a support member.  Hours 2.5

Pitot and AOA tube installation

Header tank brackets welded

Welded both mounting brackets onto the tank.  The welds aren't the prettiest in the world, but they are plenty strong and will do the job.  The top bracket is shaped like a V because it fits in a nook where two fuselage tubes are joined.  The other bracket is a simple plate welded at the bottom of the tank.  The large hose clamp around the middle of the tank is only there to provide a nice grounding point for welding.  Hours: 1.0

Mounting brackets welded

Mounting brackets welded

Leading Edge Cuff

After a little thought, we realized the main windshield needed to be installed in order to correctly locate the fiberglass wing root fairing.  That fairing locates the beginning of the wing leading edge cuff.  Good thing we checked.  The cuff was about 1/2" to 3/4" misplaced.  So after correctly locating everything a small tweaking was needed on the inboard wing cuff around the jury strut attach bracket.

Windshield Temporarily Installed

Wing Root Fairing, notice the misplacement

The outboard wing cuff is needing a lot of "tweaking" to get it to fit around the main strut attach bracket.  It is getting close, but more work will be needed to get a correct fit.  Hours: 2

Modification to the outboard Leading Edge Cuff

Cuff Modifications around the Main Strut attach Bracket