The Return of the TigerKitten (7)

Every bit of structure that will part of the surface of the finished airplane...this includes everything that serves as a support to fabric covering... must be sanded absolutely flat and true or it will show up as BAD CRAFTSMANSHIP on the finished airplane. These stringers and the upper and lower longeron caps on the rear fuselage are an excellent example of places that are easy to forget about until it's too late. I'm using 80-grit production paper on my favorite LONG sanding block to dress off the outer surfaces of all these components so that the covering will lie dead flat across them. We're going to be adding the tail surfaces shortly and it is a lot easier to do this particular sanding job now than to work around extra structure.

With all the surface sanding on the fuselage done, it's time to go ahead and install the horizontal stabilizer. The incidence angle (which happens to be zero degrees) is determined by the rear portion of the upper longeron,and if you have built everything straight and true so far, this is a default setting. Alignment is the critical deal here. I have pinned the fuselage assembly in place over the plan in order to make the drawing of the stabilizer relative to the fuselage valid as an alignment reference. If the fuselage is set up square on the board, and the stabilizer is squared off as I have it here, everything will be where it belongs. What you can't see in this shot is that I have already used a ruler to check that the distance of each stab tip off the board is tha same. With a couple of pins and a final check, a generous shot of thin ZAP locks the assembly in place.

After the horizontal stabilizer goes in, the vertical tail (the fin) is next. I squared that assembly up just the same way before glueing anything. What comes next is this little balsa sheet covering base, which is necessary because we're going to cover the entire fuselage side and fin together to create what is called a fabric fillet. In order to make this work we need a piece of structure that will function as if it were part of the fuselage side, to serve as a covering attachment base.

This is the covering base insert in place. I have tapered it to fit smoothly against the vertical fin trailing edge and sanded it to blend with the contour defined by the fin, the top longeron, and the stringers. When we get to the covering job you'll see exactly why we need this insert and how it functions.

The main landing gear base plate (F-2) is backed up on the inside by a couple of reinforcing blocks. I have drilled through F-2 and the blocks and am using a 10-32 tap to cut threads for 10-32 nylon bolts that will hold the landing gear in place. Rather than use blind nuts, which can pull loose and rattle around inside the airplane when you want to work on it, I reinforced these threads with thin ZAP and re-tapped them to provide a secure attachment.

This is the pre-formed landing gear held in place with two hex-head 10-32 x 2" nylon wing bolts (DuBro Cat. No. 164) When you are mounting the landing gear be sure that the taper in the legs, as seen from the side, appears to sweep TO THE REAR, not to the front. I meant it to be that way. This puts the main axles closer to the leading edge of the wing, with the result that the airplane is less likely to swerve under power on takeoff and also less likely to bounce on landing if you come in a bit too fast.

Here I have drilled each leg of the landing gear for installation of a pair of DuBro axle shafts (No. 247) . In order to get a dependable, secure mounting base for the wheel pants I elected to add a rectangular bracket about 1.5" long to each axle. I cut these from some scrap .030" aluminum sheet I had lying around. G-10 epoxy board or even good quality 1/16" plywood would also work. The brackets are trapped between the axle shaft assembly and the gear leg...when the wheel pants are ready to mount I will drill screw holes in each to match the openings already in the plates.

This is the left main gear leg with the wheel pant mounting bracket as seen from the outside. The broad hex nut fitting is part of the axle assembly.

With the landing gear temporarily installed, my next job was to cut, fit and glue the 1/8" balsa sheet on the chin (the lower front cowl) Note that this balsa is fitted with the grain running across the fuselage for extra stiffness.

F-10 is a laser cut 1/4" balsa sheet filler/spacer that forms the forward portion of the fairing between the landing gear mount and the bottom of the wing. Here you can see that I have trimmed and beveled it to rest squarely against F-3 and fit the curvature of the wing leading edge.

Both F-9's get trimmed as necesssary to fill out the base of the fairing and provide a solid glueing base for the balsa sheet surface.

With the wing removed from the fuselage we get a clear shot at sanding the F-9/F-10 assembly to permit the outer sheet to fit tight against the wing surface.

I used a piece of 1/8" balsa sheet sanded to a taper under the rear edge to allow it to fit snugly against the wing center sheeting. I used ZAP A GAP for this assembly because the slower setting speed gave me time to press the outer sheet firmly into place.

I have used masking tape all around the outer edges of the fairing to protect the wing center section skin as I use the sanding block with 80-grit paper to smooth and radius the fairing assembly.

I used a semi circular balsa sheet insert to provide some reinforcement along with a smooth transition for the fabric covering where the underside of the wing trailing edge meets the rear fuselage. This will probably be presented as a laser cut part in the production version of the kit.

I'm back to the sanding block to radius the edges of the insert assembly AND to blend the bottom surface of the sheet into the bottom of the longerons.

This is the front/top deck assembly all shaped and sanded, in place on the fuselage and ready for the nose cowl to be fitted.