Bulkheads

This one falls under the QB-F classification but it was not complete when it arrived but darn near.

In the bulkheads chapter, with the elite option (gull wing doors), you only build two bulkheads, the firewall and the main gear bulkhead. The canard bulkhead is pre-molded.

To make the two bulkheads, you would cut them from aircraft grade plywood using templates then cover them and reinforce them with several layers of heavy triax fiberglass cloth.

Since the canard bulkhead is molded the only work to do on it is to install the master cylinder mount/ brake pedal recess and do what appears to many, many reinforcing lay-ups.

There are two fiberglass wire ducts that run under the firewall, all the way down each side of the fuselage and then under the canard bulkhead. These should come in real handy running electrical wire, brake lines and engine controls from the front to the rear of the plane. They also help add longitudinal stiffness to the fuselage as well. So these two wire ducts are laid down in place and each of the bulkheads goes in on top of them.

All this has been done already with the quick build fuselage option.

Here is the Firewall You can see the large reinforcements running up and down on each side. Note the wire ducts come out just below the main gear pivot bolts.

The U shaped former right in front of the firewall is the gear bulkhead. Why it is called that is probably self explanatory since the two light colored posts sticking up (look like 2X4's don't they?) are the main landing gear legs. They pivot on the two large bolts you see running fore and aft through the gear bulkhead and the firewall.

At the far forward end of the keel beam is the canard bulkhead. You can see the heavy reinforcing in each upper corner and note the depression on the left for the brake master cylinders. Also note the 'wire' duct running under the canard bulkhead and aft under the door.

(As you can see, I'm well into the spar installation when I did this part)Here is a good shot of the wire ducts. The only thing left for me to do in chapter five is to mix up some thick microslurry and lay in a bead around the front side of the gear and canard bulkheads creating a nice structural fillet...

and then lay two ply plies of three inch wide BID fiberglass over the radius created on the canard and gear bulkheads wrapping half onto the floor and half onto the bulkhead. This also ties the wire duct to the bulkhead and floor as well.

Next was the canard bulkhead. I laid in the thick microslurry at the same time I did the gear bulkhead but I did not make the lay-ups on it until I had completed chapter 8 (which was the first chapter I did).

I would like to side track briefly to the topic of the RBH. RBH stands for Really Big Hatch. I read about this in the Velocity Newsletter #11. This was a builder tip submitted by Dave Black. The idea behind this is that on the standard door Velocity, removing the canard required a bit of gymnastics.

For those of you not real familiar with the Velocity, the standard door is a small gull wing hatch that does not come down past the strake. This makes entry more like your typical jet fighter- the pilot settles down into the cockpit from the top of the plane. Now, two of the canard bolts are on the inside of the plane down by your feet. So to remove the canard you would slide in head first and put your head where your feet would normally be!

Now, bear in mind that to access the back side of your instrument panel you have to remove the canard! Ouch! So Dave developed the RBH to 1) prevent having to remove the canard to access the panel and 2) if you do have to remove the canard you no longer have to stand on your head.

Well, the head stand part does not apply to the Elite (Full gull wing door) model that I have so I did not intend to implement the RBH on my plane.

Now back to the canard bulkhead... I was sanding the areas on the canard bulkhead to receive the 3 in tapes or I should say I was trying to sand the area. I found that it was very difficult to work in this area through the canard cut out. I kept twisting and turning trying to get a good shot at the work area but it was very awkward.

I was setting and looking at the amount of work I have to do in this area in the future. Nose gear door, its actuator and linkages, the hydraulic pump and a fair amount of plumbing for it, the oil cooler and cabin heat set up, battery tray, landing light and a good deal of wiring.

In the normal kit this is almost all of this is done before the two halfs of the fuselage are joined. Now I am going to do all this through two small cutouts? Hello RBH! In fact I will go so far as to say that on the quick build fuse the RBH is going to be mandatory. Well I got out Volume 11 checked the dimensions as best I could and made the cut out like so. Basically, I stayed an inch or two above the triax that ties the fuse halfs together and went halfway down the existing small hatch. I will complete the work on this area after the canard is mounted. For now though, I have plenty of room to work up in the nose. The sanding and lay-ups in this area now went much smoother. In fact as you can see here I did the best looking lay-ups I have done yet!

Smooth, even radii. Nice straight edges. This has been the first set of lay-ups that I really felt good about. Note the wire ducts.

This completes chapter five for now. The battery tray normally gets done in this area in chapter five but I am going to wait until I mount the engine and see how the CG is doing before I mount it.

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