Chapter 6: Fuse Assembly

August 16th, 2003

For some reason, the digital Camera disappeared for a while (only to mysteriously turn up again in August), so I don't have any pictures of the Fuselage assembly.  Fortunately, since I used Wayne Hicks' Inverted Table method of jigging, you can find examples on how to do this at Wayne's Website.

So, the pictures in this chapter start with attaching the Landing-Gear Bulkheads.

Instead of the plans 'hot-glue' method, I decided to try strapping the bulkheads in place.  This worked okay, but it took a lot of futzing with the straps and bulkheads to get them lined up correctly.  If I had to do this again, I would probably use pipe-clamps instead.

I also had what I thought was an inspiration in attaching the upper forward landing (remember, I am using the 'inverted' method, so I can't just lay the bulkhead in there.) Instead, I tried 'packing tape' taping the bulkhead in place.  This held the bulkhead in place, but was a royal pain to get off.  

If I had to do it again (a phrase that will be repeated a lot while I build!), I would wait to install the upper bulkhead until I turned the fuselage over (upright position).  This way, no packing tape would be needed to hold the bulkhead in place while curing.

November 25th, 2003

After a few months away from building (mostly due to a new, high-priority GPS design win that I was supporting), I finally got back to building during Thanksgiving week.

After turning the Fuselage over, I decided to fix a problem that I created when I tried BID-taping the seatback-sides while inverted (I thought the BID would stay in place on its own...IT DIDN'T!), so I had to cut out the huge bubble that formed and re-BID-tape the seatback.  

I also took this opportunity to install F28.  After a little 'adjusting', it went in perfectly and I was able to simply block it in place with various scrape from around the workshop.  I also decided to apply the BID-tape while the flox was still wet (why not?)

December 31st, 2003

Happy New Year (almost)!

After a busy December (again due to my GPS support activities), I got back to building on the last day of the year.

I started building the seatback brace, and after having read through the plans on this a couple of times, I could not fathom why the entire brace was glassed BEFORE chiseling out the foam for the birch hard-points for the fuel-selector and speed-brake.  Why not just cut out the foam before glassing (as was done with the hard-points in the landing gear bulkheads), 5-minute epoxy the birch hard-points in place, and then glass? So this is what I did.

I have left the birch hard-points un-cut for now, since I am planning on using a fuel-injected engine and I haven't decided what type of selector I will need.  I also extended the birch hard-points back about 1.5 inches, to better accommodate the electric actuator for the speed-brake (as noted by John Slade).

I plan on duplicating Bob Bittner's nice Fiberglass Speed-Brake Actuator Bracket (used by permission of Bob Bittner).  I will cad up an engineering drawing of this bracket and post it on this web-site in the near future (again with Bob's permission, thanks!)

(Bob's Note: "This is not yet flight proven!")

I'm also planning to implement Bob's Canopy Latch System, but I have a while before I have to get there.

Finally, a quick layout of the Heatduct Foam, and I'm ready to start on the Duct:

January 3rd, 2004

After glassing the Front-seat Triangular Braces, I cut them out and used them as a quick template (with 4-mil plastic underneath) for epoxying the Spacers into their correct orientation.  The Spacers were glassed as a unit (with the Hot Air Duct sides) and then cut out on the Bandsaw.

After the Spacers cured, I then epoxied them to the Seat Brace, and filleted the corners with Flox.  I then weighted down the assembly for cure. 

Using the "Template" method and weights, I was able to avoid the "drill-holes and nails" as called out in the plans.  I will admit that my method requires more "cure-steps".  I used the time between cures to move onto other parts, such as the Air-Duct.

Note the the plans say simply to assemble the Air-duct without much guidance on how to actually do it.  (Maybe drills and nails were assumed?)  I decided to use clamps.  In the first step, I applied flox to the edges, I then clamped the two edges together with the wooden spacers in between (flox on top edge).

After camping the sides of the Air-duct, I then added the top of the Air-duct and clamped it down:

This produced a "mostly square" Air-duct with the front-lower bottom of the Air-duct being narrower than the top.  This was easily corrected when installing on the Instrument-Panel by inserting a temporary spacer at that location while curing.

January 11th, 2004

Between January 3rd, and January 11th, I added the Seat-belt tube, and sanded the fuel-line depression.  I'm still not convinced I will put a fuel selector in this location, but I want the option just in case:

August 14th, 2004

I have been working off an on (mostly off), and by August I was almost ready to put the Seatback Brace in the Fuselage.

Sometime August/September?

I've lost the exact date on this sequence (and the Digital Camera's battery died and reset the date to 1998) so I'll just put this sometime in August/September.

Doing the bottom was fun.  I was not as worried about the angles on the foam as I was when I was doing the sides, so for simplicity and speed I just setup a straight-edge cutting jig and went after the foam with a Hacksaw Blade.  Simple and straightforward.  A little clean up with a sanding block and I was done.

(Note: this was much quicker than the contortions I put myself through to build a dead accurate jig...I am learning...slowly, but still it's learning.)

After all the beveling was done, it was time to attach the spacer-foam to the bottom skin. I used every spring-clamp I had plus a few weights (but that's nothing compared to what I had to do to install this bottom on the fuselage...read on!)

But before I installed the bottom, I needed to drill out the pilot holes on the Landing Gear Bulkheads. For this I needed to accurately place some reference lines.  Remember that with the "Wayne Hicks Inverted Fuselage Jigging" Method, the Upper Longerons are parallel to the work table.  This allows me to true up F-22 and the Landing Gear Bulkheads with some guidelines and then accurately place my pilot holes parallel to the Longitudinal axis.

So, I installed the Guidelines...

And dropped some reference lines (note I used an improvised bob to mark the place of the dropped line and then used the square to draw it in).  The Guidelines have already been removed in this picture because I already had the reference lines marked.

That being done, I then drilled the Landing Gear Bulkheads and mixed up some Flox to get ready for installing the bottom.  Note - I use the "corner-cut sandwich baggy" method of Flox Dispensing.

And then liberally coat the bottom surfaces.  This took several bags...

I've got a "Bow-legged" Plane!

For whatever reason, the bottom was slightly bowed (concave) and had a 1/4" gap in the center.  I have read that other builders had this problem, and the only fix (to get it to seat properly) was to add weight...lots of it.

I grabbed everything that was handy and substantial and piled it all on.  This finally got it to seat properly and it cured fine.

I then taped, and viola! Ready for Chapter 7!
(If the picture looks funny to you, the plane is actually on it side; I rotated the picture for a more friendly presentation).