Ch 12.1: Canard Mounting

Mounting the canard to the fuselage - Alignment Pins

Yay!...I get to add the first flying surface to the fuselage.  I guess technically it would be the second since I've already fabricated the main gear fairings, which are also airfoils, but this one is more exciting.

Editorial Note:  I know some people following this don't know one part from the next and it's sometimes hard to tell what's going on in my pictures.  So, going forward, I'll try to include a small pic like the one to the right that highlights the part I'm talking about.  Hope that helps.

Ch 9.5: MLG Access Close-Out

Thinking Ahead for Access

The last thing to do is close-out the top of the MLG area.  The plans have you leave two small diameter holes for inspection access to the MLG.  Since I routed the brake lines on top of the MLG, I needed slightly bigger holes to ensure I could get to the brake lines if needed.

Trace out the round corner rectangles using a template

So, rather than the plans round inspection holes, I built rectangular holes to give me more room.  I also wanted to build access hole covers to help muffle any noise coming from there.  With these, I can access any of the adel clamps holding the brake lines if I needed.

After following the plans to glass one side of the PVC foam, cut it to shape, and fit the pieces to the MLG bulkhead area, I traced rectangular panels symetrically on the port and starboard side of the horizontal panel.

View of bottom of panel with inspection panels cut out
at a roughly 45 degree angle before installation in fuselage.

These covers were then cut out with an angle inward from the top such that they would be self supporting when laid in place.  The top and side panels were then floxed in place in the fuselage.  Then, with the covers laid in place, I glassed the entire thing per plans.  Before it cures solid, I was sure to cut the inspection panel covers lose...it would have been much harder after cure.

After the the full panel is fitted and floxed in place and
inspection holes are taped up with box tape. 

After the MLG close-out was cured, I removed the panel covers that I had already cut lose and did some clean up work to make sure the openings for the inspection panel covers were nice an symetrical. Then I placed box tape all around the area were the inspection panel covers will go.

Glassed 2xBID over the inpection panel covers in place.

I placed the inpection panels in place with dry micro around the edges to help create a nice clean and gapless seal.  After cleaning up the excess micro that squeezed out the top, I glassed over the panesl with 2xBID extending past the edges of the panels approx 1".  I peel ply'd and allowed it to cure.

Inspection Panels, one trimmed up, one not, after being
removed after cure.

After cure, I popped them lose and trimmed the edges of the covers to approx 1/2" wide and cleaned up the excess micro.  I think the only thing I'll do to secure them is maybe use a dab of clear silicone sealent in a few spots.  That should keep them in place with no rattles.  In theory, I'll only need to remove them every once in a while to inspect the top of the gear or brake lines.

Inspection panels fit nicely !

Finished !  Nice MLG inspection panels that provide access while helping keep out unecessary noise.

Chapter 9 Complete...On to the first airfoil !

Ch 9.5: MLG / Fuselage Intersection Fairing

Now that the MLG fairing is done, there needs to be an intersection fairing that makes a smooth transition between the fuselage and the MLG.  The key here is that it has to allow for movement between the two.  With weight on the gear and on landings, the gear strut will flex up so the fairing has to allow that without breaking anything.

I really liked Wayne Hick's solution.  See his instructions here for details.  I will only summarize my attempt at it below.

 For starters, I crafted the fuselage side of the fairing out of left over 3/8" PVC foam.  This will form the curvature to the fuselage.  I used the large end of the Eureka CNC MLG fairing I had trimmed off as the template for the airfoil shape.  In the pic, you can see the before and after shaping the contour.




I glued the top side of the fuselage faring to the fuselage using scrap pieces of 3/8" foam to ensure the necessary clearance between the fairing and the MLG.  Afterward, glue the bottom portion to the underside including the MLG cover.  Don't worry, this will become a permanent part of the cover but it will stoll be removable when done.



Now I used other scrap Last-A-Foam approximately 2" wide to serve as the transition from the fuselage-side fairing to the MLG fairing.

I glued it to the MLG fairing butted up against the fuselage-side fairing.  I used expansion foam to fill in the gaps and began sanding to match the fuselage fairing and gently fair it into the MLG fairing.





Here you can see the both starboard (left pic) and port (right pic) from the nose looking back after being sanded to shape.  I'm not sure how I did it but I seemed to be able to shape them almost identical without the use of any templates.

Not shown (sorry) is the shaping of the back edges curving into the fuselage.  See pics below after glassing.

Once I was happy with the shape, I glassed the bottom of each fairing with 2xBID.  I wrapped the leading edge up past the center point and left an overhang at the back supported with card stock.


Here you can see the back edge after glassing the bottom and some trimming and sanding to blend into the existing MLG fairing.  Once I had it the way I liked it, I used a piece of card stock to form a template so I could get the other side to match.

I removed foam from the aft edge and used micro to fill the wedge where the top glass would meet the back edge.  It worked pretty well.



After all the glassing was done, I used an xacto saw and a Dremel with a small saw to carefully cut along line separating the PVC foam from the white Last-A-Foam.  I used a sharpie to help mark it.







After cutting the fairing loose from the fuselage, I used folded over sand paper to clean up the cut line for a nice look.  I also removed the gear and painted the exposed foam inside the fairing with micro to protect against water intrusion.  I also wanted to ensure water could not get trapped anywhere in the gap so the smooth micro finish helps ensure the water drains out the bottom cut line.

MLG Cover on the bottom with
Intersection Fairing mods

I uncovered a problem after separating the MLG cover on the bottom.  I found that I would need to make a few adjustments to accommodate where the corner screws landed for my cover.  I didn't see that coming.  I couldn't move the fasteners without causing a conflict with getting the gear in and out when needed.  So I made adjustments to the intersection fairing on the bottom.  I think it turned out fine.

Main Gear Fairings & MLG Cover Complete!

Ch 9.5: Gear Strut Fairings

Pick'in up Some Knots

Top View of Eureka CNC Fairings

Side View of
Eureka CNC Fairings

Although the MLG strut has an airfoil shape to it, it's formed in way that puts it out of alignment with the air stream when it's in cruise.  That creates unnecessary drag which reduces speed and fuel efficiency.  Several builders (Wayne Hicks, Kevin Walsh, and others) have formed fairings over the strut to realign the aerodynamic shape which reduces drag and increases speed. Kevin and Wayne did it slightly different but the result is very similar.  Kevin worked to have his made available through Eureka CNC.  These are what I used.

The fairings come in two long straight pieces that won't bend around the curvature of the strut so you have to cut it into pieces.  I cut it into 8 pieces, larger widths toward the top and thinner widths where the strut curves sharper.  I positioned the top piece about 3/8" gap from the fuselage side and went down to about the top of the brake heat shield.  I'm assuming that some of this will end up being trimmed off when the wheel pants are built and installed.

Test Fitting

Then I tested the fit by taping the pieces on each leg.  I numbered each one to ensure I put them on in the proper order.  Note that the closer to the bottom you get, the foam get's very thin and hard to keep from breaking.

Vacuum Bagging

To the left is my poor man's vacuum bagging technique with a small shop vac.  It worked well enough to keep the pieces all together and aligned while they cured.

To the right...taken after the foam has been micro'd and glassed with 2xBID. Notice the white trailing edge.  I glassed the bottom side first and then removed foam from about a 1/4" or so on the top at the trailing edge, filled the gap with micro, and glassed 2xBID on top.  This gave it a nice solid sharp edge that should be able to survive a minor hit without permanent damage.

The bottom was trimmed off to be level while sitting on the ground.  Next there needs to be a fairing built for the intersection of the MLG fairing and the fuselage side.

Onward, cab

Ch 9.4: Main Gear Cover (2 of 2)

When last we left our MLG Cover...

Now that the gear strut is in place, I can complete the removable cover for the bottom access to the "hell hole" where the main gear is mounted.  Other than the gear mountings themselves, the only thing that will be in this area is brake line connections I think.

Taped off ready
for layups

The cover has been fabricated but it has no way to be mounted.  As mentioned, I followed Wayne Hicks method of fabricating the cover.  This continues into the mounting flange and fasteners for it.  I first taped off the edges of the inside of the cover with packing tape to prevent epoxy from sticking.  Then I bondo'd craft sticks to the cover so it would sit flush over the access hole.

Looking down (inside) the
cover while layups cure

Then I set the cover in place and bondo'd the craft sticks to the fuselage.  After turning the fuselage right side up, I then laid up BID tapes from the side of the LG bulkheads down and about 1" onto the MLG cover.

Flange cured, trimmed,
with fastener holes
located and drilled.

After cure, I cleaned up the flange and located the holes for the fasteners.  Also, some clearance cuts had to be made to allow the main gear attach tabs to fit down between the flanges.  Everything is a fairly tight fit but works out great.

Installing nut plates
under the flange

I ordered Click-Bond floating nut plates (#CN614CR3P) and Click-Bond adhesive from The Flight Shop to attach them to the underside of the flange.  The rubber installation aid made this very EZ and the nut plates seem to be holding very well.  Using countersink screws make is all nice and clean for airflow.

Clean lines !

Once complete with the install, I went ahead and did some finish work with micro to create a nice clean 1/16" gap between the cover edges and the fuselage.

Onward to the Wheels and Brakes!

Ch 9.6: Landing Brake

The landing brake (LB) helps provide some needed drag during landing approach to make a steeper decent and a better view of the runway for the pilot.  It is a hinged flat board that deploys from the belly just behind the front seats.  The plans call for a mechanical mechanism to deploy it however most builders today convert this to an electric actuator.

Building the Brake
The building of the landing brake started in an earlier chapter when the brake was cut out but then re-glassed back into the fuselage bottom until Ch 9.  So the completion of the brake starts with cutting it lose.

I decided early that I wanted the hinge for the brake to go almost the full width instead of just 10" per the plans.  I'm hoping this will keep it from warping the way several builders have reported.  To do this, all I really had to do is adjust the number of attach points/screws.  I'm also widening the wooden support the actuator connects to to provide a little more crosswise support.  My hinge runs ~22" of the ~24" width of the LB.

Installing the Brake Hinge Support
I used 7 screws to attach the hinge to the fuselage and 8 screws attaching the hinge to the LB.  Other than the added number of screws/slugs to the hinge line, everything else pretty much followed plans.







Preparing the LB Cavity in the Fuselage
After securing the LB-23 hinge support into the fuselage, I routed out the interior of the landing brake cavity using a dremel routing tool to make room for the glass to be added.

I then located where the actuator would come through the bottom and beveled the foam to that area. The cavity was then glassed per plans.  At this point, each slug buried into the foam of the fuselage was drilled and tapped for 10-32 screws and the brake was test fit.  In order for the brake to hide nicely under the fuselage, micro must be used to fill the remaining depression.  I taped off the brake edges and the hinge to ensure release and filled the edges and the surrounding depression with micro. Then I closed the brake flush with the bottom of the fuselage to let cure.  TIP: I would recommend putting some kind of release agent on the tape. I almost epoxied my LB closed :-) .  This process essentially makes a mold of the inside edges and perimeter of the brake in the fuselage bottom so that when it closes it basically disappears nice and neat.  See video at the end.

Glassing the cavity

Routing out the fuselage cavity

Micro curing in the depression
surrounding the landing brake.  The
boards ensure the brake sits flush
with the bottom of the fuselage.

Installation of the Actuator
I'm using a Firgelli actuator, model FA-PO-150-12-4.  It has a 4" stroke, 150lbs of static force, and a feedback potentiometer in case you want to wire it up to an electronic indicator.  I made glass brackets similar to Wayne Hicks however I only ended up using the larger one to attach the actuator to the back of the seat. 

The brackets were made similar to Wayne Hicks brackets, with 8 ply of BID...4 running along the bottom, 4 running from the bottom and up the side on each side, with another 4 layers forming a U-shape in between the sides.  A picture would be good here, but at any point on the bracket there are 8 layers of BID.  I used a scrap piece of foam to form around which was cut the width of the actuator attachment.  I let it cure, cut it to shape, put adjustment holes in it to allow me to adjust the closure of the LB once installed.

Assessing where to mount the bracket
on the seat back.

Installed Actuator
with homemade
bracket

The fuselage side bracket is mounted in the back of seat on the passengers side close to the center seat support.  I glassed an oversized piece of birch plywood on the back of the seat.

Between the seat and the birch, I embedded two EZ-point locking nuts  vertically where two bolts hold the bracket in place.  The actuator is then attached to the bracket with an AN Pin and castle nut to secure it.  For the LB bracket, I simply used the aluminum brackets, part no. CZLB-18 available from the Cozy Girrls.

Voila !...My first moving part...Onward.

Ch 9.4: Main Gear Cover (1 of 2)

While I'm waiting for the main gear mounting parts to arrive from the Cozy Girrls, I decided to keep moving and work on the main gear access cover.

I did not follow the plans method for this.  Instead I followed Wayne Hicks method which I highly recommend.  Earlier when prepping the bottom for glassing, I did not make the joggles with the foam at the front main gear bulkhead because I new I was going to use this method.  With this method, you don't need those joggles, you don't need the aluminum slugs installed into the edges of the bulkheads, it's much easier, and will be form fitting when your done.

The first step was to stuff the area between the bulkheads with foam.  I found enough urethane foam scraps around so I didn't have to buy any.

Once the foam is stuffed, I sanded it down to the shape of the fuselage bottom and NACA scoop.  The picture to the left is in the middle of this process.


Once sanded to shape, I glassed the NACA scoop with 2 ply BID and then the rest of the bottom of the cover with 2 ply BID as well.

After the glass cured, but BEFORE I removed it, I attached two straight supports with Bondo across the NACA scoop.  These served to keep the cover in the proper shape while I work on the underside.  The picture at the left is just after I removed the entire foam plug with the top completely glassed.

After sanding the forward/aft edges of the cover to fit, I removed all but approximately 1/4" to 1/2" of foam all over the other side of the cover and all the foam around the perimeter of the cover about 1" wide.

There needs to be room for the gear so, as recommended by Wayne, I sanded some indentations under the NACA portion to ensure the cover would fit over the gear without rubbing.  Then I glassed the underside with 2 ply BID and shaped.

After that, I installed 2 ply tape along the forward and aft edges to reinforce the bare edges for the fasteners.

The only thing left to finish this up is to install the ledge and fasteners along the bulkheads that will hold the cover in place.  That will have to wait until I get the gear mounted because it would be harder to work on the installation of the gear after the cover mounting flanges are in place.

cab

Ch 8.1 - 8.5: Headrest - Part 2/2

Return to the Headrests
Ok...back to finish the first 5 steps in Ch 8.  Note it's been 9 mths since part 1 of this post.  Mostly because I wasn't working on the Cozy for about 6 months while involved in some other projects, retiring from the USAF, securing a new job, honey-dos, etc.

Since I'm not using the plans version of headrests, I can skip part of step 1 and all of step 4 but of course that work will be replaced with other work to install custom headrests.  At the beginning of Ch 8, I already cut the shoulder support.  I also ordered and received my Saab headrests and the adjustable headrest guides from a Saab dealer.  Now it's time to get it all together.

First I located where the birch hard points for the shoulder harness attachments would go.  The plans call for 8.5" apart.  This was a change made in Newsletter #50 which reduced the spacing from 11.5" based on a European safety study that gave 8.5" as the max safest distance for shoulder harnesses.  I ended up adding 1/2" and making them 9" apart.  At 8.5" they were just a hair too close to my neck...and I don't have a big neck.  Researching the archives, I found that many builders questioned the change since there was no accident evidence to really drive it.  Some chose to leave them at 11.5" and use an "H" cross piece to ensure the harness stays on the shoulders in an accident.

Shoulder Brace, inverted,
w/ birch hard points curing with 1 ply BID

With that decision made, I cut the birch hard points and glued them in with 5-min epoxy.  Then I glued the two halves of the shoulder brace together.  I decided to go ahead and glass the inside...but not leave an overhang since I'm not installing it on the seat back yet.  This allowed me to have a more solid structure to work with while I figured out how to support the headrest.  (Post build note:  as it turned out, waiting to do this after I designed my headrest supports would have been better and saved me a little weight.)

Deviation Time...
At this point I had to start doing things a tad different.  I couldn't install the shoulder brace onto the seat back until I designed the support structure for the headrests.

After some thought, I decided to install aluminum tubing for the headrest guides to slide into.  This will provide more support than just gluing the headrest guides in place.  My fear is that someone will grab the headrest and lean on it while getting into the plane so I want to make sure there's enough support in case that happens.

After ordering tubing with the wrong wall thickness twice, I finally got the right size to fit the headrest guides...3/4" OD w/ .049" wall.  I located the holes for the tubes in the shoulder brace and drilled and glassed receiving holes for the tubes into the seat back w/ 1 BID to provide a more solid hold at the bottom.  The holes aligned with the front inside edge of the shoulder brace.  Later in the build, I'll adjust the length of the tubes if needed based on where I want the center of the adjustment travel to be...then they will be floxed in place.

Pilot side holes for
headrest support tubes

Tubes used to form glass
 down into the holes

Next I cut some leftover 1/4" birch to provide support structure for the tubes on the inside of the shoulder brace.  These support the top of the tubes while the holes in the seat back support the bottoms.  The tubes go through the birch right up against the front of the shoulder brace.  The back is cut to match the angle of the seat back so it will flox to the seat back just like the rest of the brace.

Birch supports for top of headrest
guide tubes

Checking everything before glassing
in the birch supports in place w/1 BID

Next I prepared the nut plates for the harness bolts.  I followed the recommendation in the FAQs to flox/screw the aluminum squares with the nut plate permanently to the bottom of the harness hard points instead of the hokey way the plans directs you to do it.  Each nut plate is secured to the aluminum with rivets.  Holes were then drilled in the opposite corners from the rivets for #4 screws to secure them (with Flox) to the underside of the birch hard points installed earlier.

Inside of the shoulder brace.  Headrest supports glassed
in place, ready to secure the 4 nutplates with
flox & #4 screws before installing in the plane

The shoulder brace was then installed per plans and taped at the adjoining sides.  Next I sanded a the sharp back corner of the seat back round to allow the 3 ply UNI reinforcements to take the corner properly.  They were installed longer than plans at 17" instead of the plans 13".  Since these are "reinforcements", I felt I wanted a little more than a couple of inches overlapping the seat back and behind the seat.

And here is the result with headrests temporarily installed and showing different adjustment heights. What you can't see in the pic are the black plastic adjusters at the top of the tubes.  During the finishing process, I'll flox in the support tubes and hide them in a small contour of some sort on top to make it look nice.  All you'll see then is the adjusters on top.


 Another chapter down...on to chapter 9 and the main landing gear.