Saturday, May 19, 2018

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

Thursday, May 17, 2018

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

Sunday, May 13, 2018

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

Saturday, May 12, 2018

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

Thursday, May 10, 2018

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

Tuesday, May 8, 2018

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

Saturday, May 5, 2018

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

Friday, May 4, 2018

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

Thursday, May 3, 2018

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

Monday, April 30, 2018

Header tank mounting bracket

I'm currently working on a V-shaped mounting bracket that will be welded to the top of the header tank.  The piece is more complex than I originally thought it would be, due to the fact that I have to account for the curvature of the tank and also the angles of the tubes that it will be attached to.  two pieces were made from thicker (3/16) aluminum, and then tacked together to get the angle correct.  Hours: 2
Mounting bracket cut and tack welded

Saturday, April 28, 2018

Magnetometer Mount and Leading Edge Cuff

After a few days off, the magnetometer mount was completed.  The supports had to be re-worked due to a miscalculation in placement.  New supports placed and length were finalized and they were attached with solid rivets.
Completed Magnetometer Mount
Work on the leading edge wing cuffs has begun.  For a correct fit the fiberglass cuffs will need to be trimmed around the jury strut mount bracket and the main strut mount bracket.  The area around the jury strut was completed, and the area around the main strut bracket was started, but still needs additional fitting.  Hours: 4

Inboard Leading Edge Wing Cuff fit to Wing

Trimming Cuff for Main Strut Bracket


Friday, April 27, 2018

Header tank progress

Welded the bottom cap to the header tank, as well as the bottom bung for the fuel sump.  This completes all the welding of the bungs and the end caps, so the tank enclosure is complete.  I still have to weld on some mounting tabs, as well as pressure test the tank, so this part of the project isn't done quite yet.  Hours: 1.5

Ed working on the bottom of the header tank
Header tank with all bungs and end caps welded on

Wednesday, April 25, 2018

More header tank work

Over past couple days, I welded the top cap to the header tank, then welded on the three top bungs, two for fuel inlet from the wings, and one for the vent.  Then I started welding the side bungs.  Two of these are for a site tube, and the other two are for fuel inlet/outlet to the engine.  Still need to weld on the bottom plate and the bottom sump bung.  Hours: 3

Welding 3 bungs to top of header tank
Welded bungs for site tubes (front) and engine fuel inlet/outlet (top)

Saturday, April 21, 2018

Rear Baggage Panel and Magnetometer Mount

To make it easier to access area behind the rear baggage bulkhead we decided to cut the existing panel into two pieces. A 1" overlap of the panels at the three middle attach points secures the panels.

Where there was one, Now there are two
We are planning on mounting the Garmin GMU-11 magnetometer in the wing.  A non-magnetic mount needed to be constructed.  A paper pattern was created, which was transferred to aluminum and cut out.  Hours: 2
Paper pattern and Aluminum part

Header Tank

Built a small wooden jig with notches to hold the header tank in a horizontal position during drilling.  Drilled holes for fuel inlet, outlet, and a site gauge tube.  Started welding one fuel inlet bung, and tacked the top lid on the tank for later welding.   Hours: 2.5
Drilling holes in side of header tank

One fuel bung welded, top lid tacked in place