We have completed the five bottom wing skins and are now ready to finish assembling the top wing skin mold's leading edge. Here is a picture of me (Darryl) standing in front of our hanger at Livermore Airport (LVK) and the 5 bottom wing skins laid out behind me.


You can begin to appreciate the size of the wing for our little airplane! Without the wingtips, the
wing is about 30 feet long.

This coming week Chuck and I will be finishing the top wing skin mold.

We have just finished our third bottom wing skin! We are now able to make one part a week.


Here are our first bottom skins for our wings. This is the outside (or bottom) surface. There are two layers of fiberglass on the outside, next is a 1/4" last-a-foam layer, followed by a layer of fiberglass on the inside surface, for a total of 3 layers of glass. All three parts have been post cured at 130+ degrees for two hours.

Next week we will make bottom skin number 4, that will become the first outboard half of the outer wing. It will differ from the first three because it will have a removable inspection cover/window for to allow visual inspection and removal of the aileron belcrank and linkage. The following week we will make wing skin number 5 that is a mirror image of number 4. After that we will finish the top skin mold and begin to make the 5 top skins.

Our First Wing Skin!



The picture above shows the first of 10 wing skin parts we will be making in order to build our wings. Here is what went into making this part....

Plugs, molds and wing skins

Since October, we have been working on making molds for our wing skins. We decided to create a "plug" of the wing cross section and use that to make an upper and a lower wing skin mold. The plug is about 6 feet long and is a very accurate representation of our wing's airfoil. We got help from our fellow EAA 663 member Jack Burke and his homemade CNC machine. His machine accurately cut 8 ribs matching Chuck's design. In early October, about the time we moved into the new hanger, we glued together the ribs and spars to form the plug's skeleton.

   
Three views of the framework for the wing plug. The 8 ribs were cut on Jack Burke's CNC machine. We then glued and nailed wood spars onto the notches in the ribs. The plug is now ready for us to glue on a plywood skin. (October 19-21, 2009)

Next we glued a thin birch plywood skin over the framework. In order to get the plywood to bend around the leading edge without cracking, we soaked about 12 inches of the plywood in an ammonia and water mixture to soften the wood fibers. Other than a small mishap in which Darryl's wood, cardboard and polyethylene sheet trough decided to come apart, the set up worked pretty well.

    
 Our makeshift water trough        Getting ready to glue the plywood onto the plug frame. (Oct. 22, 2009)
containing ammonia and water.
(Oct 21, 2009)



Part way there! (October 22, 2009).



The plug with top plywood skin drying with strap clamps keeping it on tight (October 22, 2009).


Bottom plywood skin glued in place (October 29, 2009).


 
Here is the plug after we have put a layer of
fiberglass over the plywood skin. February 2-10, 2010)

After fiberglassing the plywood skins on the plug, we found that the surface was not nearly as perfect as we had hoped! There were lots of peaks and valleys which we needed to fixed. We first tried a plaster-like product called "ProForm". We figured that it would be easy to apply and sand down. Unfortunately, the plaster did not stick to the fiberglass. When we started sanding, the plaster just chipped off. So we removed all of the ProForm and went to "plan B" which was to cover the entire plug with epoxy and glass microspheres (also known as "micro").

 
Chuck squeegeeing on ProForm plaster and Darryl inspecting the dried plaster (February 10-11, 2010).


Because of the cold weather and other outside activities (like the holidays and Darryl and Renee buying a new house) we did not accomplish a lot on the plug between November and February. We did, however make the seat back bulkhead for the fuselage (see below).

 
Seat back bulkhead, forward facing side.              Seat back bulkhead, aft facing side.


Completed seat back bulkhead with cutouts (November
24, 2009).


Completed seat back bulkhead with one luggage cover
in place (November 30, 2009).

Getting back to the wing skin plug, we spent most of the month of February coating the plug with micro and carefully sanding to get as smooth a surface as possible.



Here is the plug after we have covered it with a slurry of micro. We spay painted
the micro surface with green paint so that we could see where the low spots
were as we sanded it down. Note the 7 foot long aluminum extrusion that we
used to sand the surface.

We did several coats of micro, followed by a lot of sanding. After a few cycles of this, we got smarter and began to use bondo get the final low spots filled in. By the middle of March we were pretty happy with the overall shape of the plug, so we began applying a "high fill" primer on the surface and carefully sanded to get the final surface we wanted. This did this step several times for both the top and the bottom sides of the plug.  Here is what the plug looked like at this stage:
 
Plug with surface primed and sanded (Mar 18, 2010).   Plug ready to be waxed (Mar 26, 2010).


Here is Chuck looking pretty pleased with the wing plug. We are
now ready to make the top and bottom molds for the wing skins
(March 29, 2010).

On March 29th, we made the bottom mold. First we clamped  a very straight piece of wood onto the leading edge of the plug. The wood allowed us to create a flange on the leading edge of the bottom mold. When we make the top wing skin mold we will make a matching flange on it so that the two skins will mate precisely when we put the wings together. I will go into this later on in more detail.



Wood strip clamped to the leading edge. This will create a flange on the mold.


In order to make the bottom wing skin mold, we started by covering the bottom surface of the plug with a gel coat layer, which is made up of resin, Cab-O-Sil (a powdered glass material) and pigment. The Cab-O-Sil makes the gel coat layer very stiff, so that it doesn't drip or flow. We let the gel coat cure for about 2.5 hours and then covered it with seven layers of fiberglass.


Chuck spreading the gel coat layer with a squegee (March 29, 2010).



Bottom wing skin mold after the seven layers of fiberglass had
been applied on top of the gel coat. Note that we used a straight
piece of wood to create a flange on the leading edge. The flange
will be important later on when we make the upper wing skin
mold March 29, 2010).



Here is a picture of the mold after it has been trimmed and placed
back onto the plug (March 31, 2010).

The next step took some thought on our part. Basically we needed to put a backing on the flange and also make sure that the flange edge had a clean and sharp corner with no gaps or pockets. To do this we attached the mold to the plug by inserting screws all around the side and back edges to make sure it would not shift. We then applied strips of fiberglass onto the back side of the leading edge flange.


Next we clamped the wood backing on top of the wet fiberglass and then filled in the gaps with a mixture of cotton fibers and resin (also known as flox)..
 
Wood backing clamped onto back of      Adding more flox to fill in the gaps on
flange.                                                 the wood backing.


Since the mold was still pretty flexible, the next step was to make it as rigid as possible. We did this by adding foam stiffeners going lengthwise and chordwise while the mold was still attached to the plug. We fiberglassed over the foam which resulted in a very stiff and inflexible mold. Here are a couple of pictures of this process:

 

At this point, we were able to start making the top wing skin mold. Basically, leaving the bottom wing skin mold attached to the plug, we turned over the plug and then fabricated the top wing skin mold the same way we did the bottom.



Here is a picture of the top wing skin mold. The leading edge is towards the
left and the trailing edge is on the right side of the photo. There is a flange
on the leading edge that was created by presence of the flange on the lower
wing skin mold which we left in place when we made the top mold. Notice the
bottom wing skin mold in the background (April 28, 2010).

After finishing the layup of the top skin mold. we removed both molds from the plug. We now concentrated on the finishing of the bottom wing skin mold. First we needed to attach a wood extension to the leading edge flange. This would allow the fiberglass of the leading edge to be supported. We would then trim most of that away. Here is what the extension looks like:

Here is the mold with the wooden extension screwed into place. The mold has been coated
with 3 layers of wax.


Before we tried to make our first lower wing skin, we made two test parts that were only 10" wide. From the tests, we concluded that we would do the skin in two separate vacuum bagged layups. The first would consist of the two outer layers of fiberglass and the 1/4 foam core. After curing, we would then do a second layup in which we apply the single inside layer of glass. It would be a bit more work and would use more materials (peel-ply, release/cauls and polyester fiberfill bleeder), but would give us more consistant results.



Vacuum bagging the first bottom wing skin. This was actually the second lay-up
where we have applied the inside glass layer over the foam. The wet fiber glass
is then covered with Dacron polyester cloth (peel-ply) followed by perforated butcher
paper ("release/caul"). Polyester fiberfill ("bleeder") is then added on top in order to
absorb the excess resin. The entire mold was then enclosed in a polyethylene bag
and vacuum applied. You can see some of the resin being squeesed out along the
edge nearest you in this picture.



The first look at our wing skin!  The release/caul and polyester fiberfill bleeder have been
peeled back to expose the peel-ply and inner skin. The peel-ply is fairly easy to remove
leaving a nice clean surface which is ready to be bonded to the ribs and spars (June 8, 2010).



Here is the first lower wing skin sitting on its mold. It is starting to look like a wing!
(June 8, 2010)

All moved into the Hangar and building our airplane!
Since the mid-October we have been in our new Hanger at Livermore Airport (KLVK). Our first order of business was to get everything stowed away and organized. Here is a picture of our hanger now that we are all moved in.


Our hanger is located on the extreme northeast corner of the airport. Right
now it is pretty noisy since there is a lot of construction going on with the
building of a new freeway on ramp for Hwy 84!

As you can see above, we have done a pretty good job of filling the hanger. It is hard to believe that most of that stuff was in my garage. The big work table is set up on the left side of the picture just behind the Harley. The hangar came with a nice loft which we are using to store our completed parts, foam blocks and molds.

Now we are working on making the wings. We completed the main wing spars earlier this year (see the July 31st entry below) and last month our friend and fellow EAA 663 member Jack Burke used his home made computer controlled mill to cut out a bunch of wooden ribs for making a wing section plug. Chuck designed the parts and sent the drawing files to Jack. He then used the drawings to program his mill. Here is a picture of the mill in action:
(need pic of mill IMG_4774)

Within a day or two of moving in we got to work gluing the plug's ribs and longerons together.
 

The plug is glued together and ready to have thin plywood skins added.

On October 22 we took the plywood skin for the top surface and soaked a 10" wide leading edge in water and ammonia to make it soft enough to bend around the leading edge. Other than a small mishap where the trough had a major leak, the technique worked out pretty well. Here is a picture of the plywood soaking in the water/ammonia trough.


Top plywood skin for the plug soaking overnight in water and ammonia to
make it bend better for the leading edge.

The next day we bonded the top plywood skin to the plug frame.


Straps holding wooden top skin in place while the epoxy sets.

We discovered afterward that we might have been better off if we had done the top skin in two stages. Trying to bend the leading edge and entire top surface was a handful, and there were some small bulges in the top surface. We ended up making two length-wise cuts in the top skin so that we could re glue the high spots.


Reworking the top skin. We turned the plug over and added 3/4 x 3/4 strips
of wood to the underside skin and clamped the skin down well.

By November 12th we had finished reworking and sanding the top skin and were now ready to glue on the bottom skin.


The plug is upside-down with the bottom skin glued into place.

The next step on the plug will be to add one or two layers of fiberglass. We will need to sand the skin to a very smooth surface so that we can make molds for the top and bottom wing skins.

In the meantime, we fabricated the seatback bulkhead this week. Here are a couple of pictures of that assembly.



Seatback bulkhead foam. Two areas have been machined down and will
be where openings will be cut out for access to the luggage area.


The front surface had been wetted with resin and micro and the first layer
of bi-directional fiberglass is being applied.


The second layer of bi-directional fiberglass has been applied and squeegeed.

Our slight detour: more work on Walter Treadwell's Sikorsky S-38 project. 

Last month we made some new parts for Walter Treadwell's Sikorsky S-38 amphibian project. As you may remember, we made four fuel tanks back in the beginning of the year. This time we made  engine nacelles which form a streamlined area behind each radial engine.  Walter provided us with a nacelle "plug" for us to make a mold. Since he has two engines, his project requires 4 nacelle halves. Chuck and I made a few minor modifications to his plug and made a trim fixture and a mold from it. 




Here is a picture of the engine nacelle plug. This is formed into the shape
of the final part. The plug is used to make the mold for making more parts.

In order to make a mold from a plug, you first have to apply 3 or 4 layers of wax to its surface. I use Minwax, which is easy to apply and buff out by hand. After the wax has been buffed, a smooth and even coating of PVA (polyvinyl alcohol) is sprayed onto the plug surface. The PVA is a mold releasing agent, which makes it easier to remove the mold from the plug, after the part has fully cured.

While forming the mold off the plug , we learned how to make a "gel coat" surface. We made our own gel coat by mixing  a type of glass powder called "cab-o-sil" into the epoxy resin. The resulting mixture makes a very thick slurry of resin which does not run or drip when applied to the plug. After the gel coat had a chance to "set up" and thicken for a couple of hours, we then began adding pieces of fiberglass cloth. We used quite a few layers and several different types of cloth that we had on hand so that a fairly thick and stiff mold was produced. After allowing it to completely cure, I was able to pop it off the plug fairly easily. Here is a picture of the new mold:



Brand new mold mounted on sawhorses. Note the smooth shiny gel coat
surface.

We also made a trimming fixture which was formed off the plug as well, but unlike the mold, we did not need to use a gel coat.


This is the trim fixture. As you may be able to see, it still needs to be trimmed.


As of the week ending Friday, September 18, we have completed 3 of the four nacelle halves. Two of them were trimmed and delivered to Walter. After test fitting he determined that the trim line needed to moved 1/2 to 5/8" on each longitudinal edge. Because of this 3 more nacelle halves were made (total of 6 parts made).



Here is one of the 6 completed nacelle halves.




Here is a picture of one nacelle being test fitted onto the Sikorsky.

On October 12th, the last part was molded for the Sikorsky engine nacelles. We are now ready to move to the new hanger and start working on our project 100 percent!

RB Aero is moving!


After 3 and a half years on a waiting list, we have a hangar!  We will begin
renting a hangar at Livermore Airport on September 26th. Needless to say,
both Chuck and I are pretty excited.


Future home of RB Aero!

This represents a new stage for us and the timing is pretty good. We are assembling
a 6 foot long wooden wing section which  will serve as a "plug" for making the wing molds.


This 6 foot long wing section will be covered with a thin birch plywood skin. It will be
covered with a single layer of fiberglass and then finshed to mirror smoothness (well almost!).
This part will serve as a "plug" from which the top and bottom wing skin molds will be created.

My garage, "Center Street Hangar" was getting a bit tight since the parts we are now
making are getting bigger and pretty soon we were going to have to put the pieces
together. We figured that we could complete the wings in my garage, but after that we
were going to have problems. Now we will be able to make the wings and forward
fuselage in a real hanger. 

Another advantage will be having the help and expertise from our hanger neighbors,
most of which are  EAA 663 (Livermore's local Experimental Aircraft Association
chapter) members. So we think that the timing couldn't be much better!

Chuck and Darryl's
Experimental
Aircraft Project



Welcome to RB Aero's blog. This project is a partnership
between two brothers: Chuck and Darryl Ray.  We are
building a prototype composite airplane to meet the FAA's
Light Sport Aircraft specifications. Chuck has designed the
aircraft and the two of us are building it.

Here is what our design looks like (excuse the missing nose wheel
and right side landing gear!)

We hope that you will enjoy our building blog. Here is our most
recent update:

Welcome back

July 31, 2009

Here is an update on our aircraft building project. I have been a bit delayed getting this report out because my hard drive on my laptop died last week. Luckily, a local computer tech was able to retrieve (I hope) all my files and pictures!

Flash!  My new laptop arrived today! I will miss my trusty old Dell Latitude but it was over 10 years old and couldn't handle high speed internet very well. I am very relieved that I can now go online without using a dial-up modem.


So here is what has been happening:
 
I am happy to say that we have been very productive over the past few months. As of last week we have completed the 4 main wing spars for our project.

We made two outer main spars (one for the port wing and one for the starboard wing), and two center main spars. The reason we have two center main spars is because the two spars will be bonded together to make an extra strong double spar for mounting the two wings. These parts have been the most challenging and complex layups of our entire project.

Here is a diagram of what the main outer spar looks like. Note that it has a
"C" shape. The two bent sides facing away from you are the spar caps containing
carbon fiber pultrusions which make the spar extremely stiff and strong.




In this picture, you can see where the port main spar goes in the wing.

We had to make two molds to make these parts. One 12 foot mold was created for making the two outer main spars. This mold was made using two aluminum L-brackets for the sides (spar caps) mounted to a smooth fiberboard base. The mold, and the resulting outer spars are very straight. We used carbon fiber pultrusions in the spar caps to make the resulting spars very stiff and strong. Since the forces become less as you go out towards the wing tip, the carbon pultrusions were cut to various lengths so as to reduce the amount of carbon the farther out you go.  Over 6 layers of glass cloth were used on the inner 1/3rd of each outer spar and 3 layers on the outer 2/3rds.



Here is a picture of the mold for the outer spars. Note the aluminum rails which
form the spar caps.




Here I am (Darryl) holding the first outer spar for the whole world to see. (No one noticed)





Here is a picture of the port and starboard spars on the living room floor.
This type of storage requires a very patient wife!

Next we made a mold for the two center main spars. The mold is curved so that the center spars would bend upwards at a three degree angle, producing dihedral wings. Putting dihedral into our wings makes the aircraft more stable. Because of the curve in these parts, we decided to bend and epoxy-coat our carbon pultrusions into bundles before doing the actual spar layup. We used a flat board and inserted nails to make a bend jig.



Here is a picture of the carbon pultrusion bundles in the bending jig.

Unlike the outer spars, the carbon pultrusions in the center spars run the full length of the parts.The top carbon pultrusions were about 1/2" shorter than the bottom ones however. The bundles turned out great, holding their shape and turning out to be very stiff. After fabricating the 4 bundles, we then used them to make the spar caps for the front and rear main spars. After trimming, Darryl cut out matching holes so that the aileron, elevator and flap linkages can pass through the spars.



Here is a picture of Chuck standing behind the two center main spars. Note the
upward curve which produces the 3 degree dihedral in the wings.

Finally, Chuck has been using a friend's mill to machine the aluminum brackets that will be used to attach the outer spars to the center spars. This will be the main point for attaching the wings to the airplane.



Here is Chuck at the mill machining a mounting bracket.

Well, that is a quick overview of our progress on the four main wing spars. We hope to make more wing parts in the next few months. I hope to be a bit more timely in my reports since things are beginning to move much more quickly now. Please feel free to comment on our blog.

6 Month Overview
It has been over 6 months since I last updated the RB Aero blog. After giving an
advance composite workshop with Zeke Smith at the GoldenWest Fly-in (which
was in mid-June) progress on our project has been pretty slow. Chuck did a lot
of design and stress analysis work on the area of the fuselage where the wing
and landing gear are attached as well as on the engine mount. We also have
been working on some fuel tanks for another airplane builder in our Experimental
Aircraft Association Chapter group (EAA Chapter 663). In October, our nephew
Brian Ray paid us a visit. Now that the new year is here Chuck and I are both very
anxious to get going on our project.

Project highlights for the second half of 2008:

• We did complete the fabrication of one important set of
  parts after our GoldenWest trip: We made our two ailerons.
• Chuck made a lot of progress in analysis and design
  details for the engine mount, the nose gear and the
  fuselage where the wing and main landing gear attach.
• We have settled on a new design for our ruddar pedals.

 

Brian and Chuck standing in my garage, aka "Center Street Hangar".

Ailerons
In the last week of June we cut out the two aileron foam cores. There is something very
satisfying in a creating a completed core out of a block of foam in less than one minute!
Below is a series of images documenting the use of  the large hot wire tool to cut out
one of the ailerons:


In the series of photos above, Chuck (in the background) and Darryl (in the foreground)
work together to cut the foam with a hot wire tool. Note that the wire follows a white
template that determines the shape of the part. Once we have cut all around the template,
we can slide out the completed core (last large image).



We took the month of July off, but got back to work finishing the ailerons in August. Here are
some pictures of the ailerons being built:


We used the Dremel tool to inlet  areas where each backing plate will go. Next we used
5-minute epoxy to attach the two ailerons to the sides of our work table. We embedded
the long steel rod counterweights to each leading edge using microspheres and epoxy
("micro"). We also embedded the 6 backing plates.


First layer applied to the lower surface of starboard aileron. The fiberglass cloth started from
the trailing edge, around and over the counter weights,leading edge and ending about 1 inch
past the hinge backing plates on the top surface.




Starboard and port ailerons looking at the inboard ends.

Rudder Pedal Design Change
One day in early August we were visiting another builder's hanger and liked the way his rudder pedals were designed. Chuck realized that it was a better configuration than he had been planning so he went back home and redesigned our pedals. Here are before and after views.

             
              OLD DESIGN                                   NEW DESIGN

With the old design on the left, the assembly is mounted to the floor while the new design on the right has the pedal assembly hanging down from the side. This new design is lighter and can handle the forces better.

Engine Mount and Nose Gear
Chuck has worked on the details for our engine mount as well as a new design for the nose gear. Here is a view of the front fuselage showing how the nose gear and engine mount attach to the firewall:


On the left is the nose gear which will mount directly onto the firewall. The yellow tubing in a
star-like pattern is the new engine mount.


Stress Analysis of Fuselage where Landing Gear and Wing Mount.
As I mentioned before, Chuck has also been working on the design and stresses of the area where the wing and main gear attach to the fuselage. This has to be the strongest part of the aircraft because some pretty strong forces interact here.



This is an example of what one of Chuck's stress analysis or finite element analysis (F.E.A.) outputs look like. This image is a cutaway view from the right rear looking forward towards the pilot's seatback. The reddish areas are zones of the higher stress. From this type of analysis, Chuck was able to modify the design to reduce the stresses on the fuselage to acceptable levels.

Sikorsky S-38 Fuel Tanks
Chuck and I volunteered to help out another EAA Chapter 663 builder on his project. We fabricated 3 fuel tanks for Walter Treadwell's Sikorsky S-38 flying boat project.


This is a painting of a Sikorsky S-38 flying boat as it would look in the late 1930s. The project that we are building the fuel tanks for is a 65% scale replica. It will be a two seat aircraft powered by two 150 horsepower radial engines. We began work on the Sikorsky fuel tanks in September. First off we needed to make some modifications to the mold for the lower tank half. The main modification was to improve the draft of the lower mold's short ends. We did this to make it easier to pull the cured part out of the mold.

 
Adding inserts to the ends of the mold. In the first image, the inserts are in foreground and mold in the back. The second picture shows Chuck fitting one foam insert in preparation for bonding and covering with fiberglass.


The two foam inserts were bonded into place and covered with a layer of fiberglass. After curing, the inside surface of the mold was sanded smooth. We finally made our first tank-half on October 2nd. We waxed the inside of the mold first and then sprayed on a good coat of mold-release. Next we applied 4 layers of fiberglass to the mold and finished by  vacuum bagging the part.



Vacuum bagging our first tank half.

After fully curing the parts, we removed the mold from the vacuum bag and peeled off the release-caul and bleeder. With a bit of effort we were able to pull the part out of the mold.



Our first fuel tank half!

By the end of the second week in November, We finished making the 6 fuel tank halves.

  
This picture shows the three pairs of fuel tank halves sitting on a work table.

There is still more work to be done on the fuel tanks. We will need to trim them, add internal baffle/stiffeners, add vents and fuel line connectors, and last but not least, bond the two halves together. We hope to accomplish these tasks before the end of January. (Famous last words!).

For those who want to see what we accomplished each week, below is my weekly summary:

Week ending Friday, January 2, 2009
Chuck came over this past Wednesday. We worked a bit on the Sikorsky fuel tanks. We also discussed our game plan for the next couple of weeks. We are ready to really make progress in 2009!

Week ending Friday, December 26, 2008
No physical work performed on the project  this week.

Week ending Friday, December 19, 2008
No physical work performed on the project  this week.

Week ending Friday, December 12, 2008
On Saturday the 6th, Darryl cut out the fuel tank rib/baffles. Began to dremel bevels in the foam. Next step is to put dry micro in the scalloped cutouts.

Week ending Friday, December 5, 2008
No physical work performed on the project  this week.

Week ending, Friday, November 28, 2008
Walter had given us the internal ribs/baffles to go inside the fuel tanks. Most of the parts had not been cut out and needed to be glassed on one side. Darryl did a vacuum bag layup to apply glass to the blank part.

Week ending Friday, November 21, 2008
Did not get together to work on project. Chuck trying to finish Jack Burke' engine mount FEA. Chuck updated our schedule. If we work like mad, we might start flight test in mid 2010.

Week ending Friday, November 14, 2008
On Tuesday Darryl cut glass and prepped for making 2 top fuel tank halves. Wednesday, Chuck came over and we made top half number 2. The next morning we molded the last top half. We now have finished forming the parts for 3 Sikorsky fuel tanks! Chuck trimmed one pair to the proper dimensions.

Week ending Friday, November 7, 2008
Did not get together to work on project. Chuck began to revisit the wing spar design. We are approaching the point when we will begin making the wing spars and need to finalize the spar/fuselage mounting, landing gear mounting, flap and aileron actuation designs.

Week ending Friday October 31, 2008
Sanded and prepped the top mold. I ended up grinding out a air void in one corner and filling it with micro. On Thursday, we molded our first top part. Chuck studying our design's expected electrical demands. Day VFR --4.7amps, Night VFR --7.0 amp with 13.75 when landing lights on (not use often). Chuck is thinking that we will use an Odyssey 680 battery which weighs 15.4 lbs, with day VFR could run 3 hours and night VFR for 2 hours without a generator. That should give a reasonable safety margin if lost the generator.

Week ending Friday October 24, 2008
On Thursday we molded our 3rd (and last) bottom fuel tank part. Chuck continued on nose gear design. Did weight comparison of several design concepts. The Zenith design (mounted to firewall) with shock cord looks promising with a 6 lbs savings over our original design.

Week ending Friday October 17, 2008
Saturday (October 11) Chuck and I flew N9396Hotel Cessna 172 to Cloverdale for the Zenith open house. Bruce Cruishank and his wife were there, and Bob Farnam flew in with his wife as well. Great flight going and returning. We were both glad that we practiced the crosswind takeoffs and landings the day before. Chuck had cataract surgery this week so we did not get together. Chuck worked on nose gear design.

Week ending Friday October 10, 2008
Tuesday Chuck was here. We went to Livermore airport to show Walter our first part. On Wednesday we prepped and molded our second part. Another success! Friday Chuck and I rented Niner six Hotel and did some touch & gos at Byron and Livermore. Since the weather report was for gusty winds both today and tomorrow we wanted to get some cross wind practice for our flight up to Cloverdale. It was fun and we both felt much more comfortable after the practice.

Week ending Friday October 3, 2008
On Saturday Chuck and I went to the EAA663 barbecue at the Livermore airport. Earlier in the day we picked up two compressors and a paint sprayer from Ken Coe. Ken gave us one of the compressors which was an old one that he had found while "dumpster diving" at the airport. Ken says he has found a lot of great stuff that way!  While the tank had a leak, the compressor worked great. We will probably buy a new tank from Granger, but with a free compressor we got a great deal.

On Thursday, Chuck measured the engine to document it so that he can design the engine mount. We filled some depressions in the lower mold as well as the cut line with micro and used a hot box to cure. On Friday we prepared and vacuum bagged the  first part. Came out great.

Week ending Friday September 26, 2008
Went to Livermore airport open house. Chuck volunteered to help out the EAA663 group and Darryl loaned them his portable awning. It was a fun event. Chuck worked on Jack Burke's engine mount FEA. Chuck started to worked on engine ring mount design.

Week ending, Friday September 19, 2008
Sanded entire lower mold surface and micro filled corners of new ends. Finished gluing and shaping foam between outside wooden mold stiffeners.

Week ending, Friday September 12, 2008
This week we modified both short ends of the lower mold to improve the draft of the mold sides. We used a pieces of blue foam, dry micro and one layer of glass.

Week ending, Friday September 6, 2008
We began working on a new project for another experimental aircraft project. Walter Treadwell is a member of our EAA group at Livermore Airport. He is building a 65% scale amphibian aircraft based on the Sikorsky S-38 flying boat originally built in 1928. See August 1st entry. We agreed to fabricate 3 fuel tanks for him. Walter already made the molds for the top and bottom halves of the fuel tank and had made one set earlier, but because of a epoxy allergy that he has developed, he was looking for someone else to make the rest of the tanks. We picked up Walter's molds and his first fuel tank halves. Chuck and I spent several hours inspecting the molds and discussing how we would tackle the project. We rounded and smoothed the edges and corners so that when we vacuum bagged the molds, we would not puncture the plastic bag. Darryl added foam to the outside of the lower mold.

Week ending, Friday August 29, 2008
Worked on Ailerons. Trimmed and sanded the trailing edges and cut them to their final (66.25") length.

Week ending, Friday August 22, 2008
in July, Chuck and I started to get back in the groove. Actually, Chuck has been pretty busy doing his stress analysis on the fuselage area where the wing spars and landing gear attach.

Week ending, Friday August 15, 2008
This week we made a lot of progress on the ailerons. On Monday, I worked on the aileron pushrod brackets. These two aluminum brackets will be riveted to the inboard end of each aileron.

Tuesday I worked on the 6 hinges for the ailerons.

Wednesday, Chuck came over and we worked on finishing the pushrod brackets and removing foam on the inboard ends of the ailerons where the brackets will be attached. We sanded all surfaces. We again attached the two ailerons to the side of the table. We took special care to make sure that the starboard aileron was straight as we attached it to the table with several dabs of 5-minute epoxy. The first layer we applied covered the lower surface from the trailing edge, around and over the counter weights, over the leading edge and ending about 1 inch past the hinge backing plates on the top surface.

Thursday morning, we came out early and inspected yesterday's work. Looked great. We removed the parts from the work table and laid them bottom-side-up on the table. We trimmed the trailing edges with the Fein Multitool. Next, we then painted the trough on the trailing edge with resin, then filled with a fairly dry micro. We finished this step at 10:00AM. We took a two hour break and then wrapped the ailerons in black polyethylene sheets and put in the sun to heat cure for one hour. This made the micro on the trailing edge hard enough to sand. We also carved off the excess foam from the top side of the tailing edge and also removed the peel ply so that we would get a good bond. Finally, we sanded the top foam surface flat.Next we added some dry micro to patch some of the areas where foam had been lost such as where the 5-minute epoxy was attached and also near the trim lines.  After that, we put the ailerons in black bags to heat treat. After the micro was cured, we attached the ailerons to the table with 5-minute epoxy, and made sure that the starbord aileron had no twist. We applied one layer of fiberglass to the top surface. We were done by 7:30PM (about a 10 hour day!). We ended up doing 3 separate resin operations on the same part. This is the advantage of a long, warm summer day.

On Friday we removed the ailerons from the table and razor blade trimmed the trailing edges. The parts looked very nice. There were a few bubbles which we filled with dry micro. One bubble we pressed down with a weight. Again we heat treated the parts for about an hour and a half. We carved out the inside end of the starboard aileron and checked the fit of the pushrod brackets.

Week ending Friday, August 8, 2008
I worked alone this week. Sanded the aileron surfaces and cleaned up the micro residue. Also drilled out the holes on the backing plates so that we can add flox when we put the fiberglass skins on. Chuck has been working on finite element analysis and design modifications on the area where the landing gear, wing spars and fuselage all come together. He is considering the stresses created when the plane lands on both main gear as well as on only one wheel. It is the second case that puts the most strain on the aircraft. Chuck has had to make a few, relatively minor changes and now feels confident in the strength of the design.

Week ending Friday, August 1, 2008
This was the first time since we started our project that we did not attend Oshkosh. We were both pretty sad about it, but we both agreed that we couldn't afford it this year. Tuesday, Chuck and I met with another experimental homebuilder, Walter Treadwell at his hanger at Livermore Airport. Walter is building a 55% scale replica based on the Sikorsly S-38 amphibian. Chuck and I have volunteered to make 3 fuel tanks for his project. He has already made the molds and fabricated one tank. We will vacuum bag the rest of the tanks. We are looking forward to using our vacuum bag skills again, our only concern is that this will take some time away from our project. One great benefit of visiting Walter's project was seeing his rudder pedals. It turns out that they are made by Van's for several of their aircraft including the RV-6. The best news is that we can buy them complete from Vans!The price is reasonable so we won't have to make our own.

On Wednesday we worked on the backing plates for the two ailerons. We used the dremel tool to inlet the areas where each backing plates will go. Next we used 5-minute epoxy to attach the two ailerons to the sides of our work table. We embeded the long steel rod counterweights to each leading edge using microspheres and epoxy ("micro"). We also embedded the 6 backing plates.

Week ending Friday July 25, 2008
No physical work performed on the project  this week.

Week ending Friday, July 18, 2008
No physical work performed on the project  this week.

Week ending Friday, July 11, 2008
Chuck and Sharon on vacation. No activity

Week ending Friday, July 4, 2008
No physical work performed on the project  this week.

Week ending Friday, June 27, 2008
This week I did some practice tig welding steel. Also worked on the 8 number CS132 and the two CS135 elevator hinge brackets. Chuck and I cut out the two Ailerons using the hot wire. The starboard aileron foam core ended up with a twist. We will be able to staighten it out when we put the skins on.

Chuck has been the busy one this week. He has been working out the details on all the metal parts needed to finish and mount the elevators to the horizontal stabilizer. Mechanically, this is our most complex assembly to date.

This figure shows the left (port) stabilizer on top with the two mounting brackets and the center bearing assembly in place. The parts are shown separate with arrows to give a clearer view. Finally, on the bottom are larger models so that you can get a better view of each part. A mounting bracket is on the left and the center bearing assembly is on the right.

Chuck also worked on a list of parts to order from Aircraft Spruce as well as finalizing the aileron design so that we can begin cutting them next week.