Month: March 2019

Vertical Stabilizer

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Tonight after work I spent a couple hours working on the vertical stab. Before mounting it to the fuselage, the forward spar had to have 5/8th of an inch trimmed off.

Here is the spar after trimming and filing the edges smooth.

I then mounted the stab to the fuselage and clamped it in place.

The height relative to the fuselage is important. I taped an Allan wrench to the rudder hinge to use as my reference line and to ensure everything was aligned.

After measuring the verticality of the stab by measuring from the tip to each end of the horizontal stab, I confirmed it was aligned, And then used my angle drill to drill the rear spar to the elevator stop, then inserted the bolt temporarily.

Here is the aft of the rear spar. I then did the same thing for the second bolt through the elevator stop. I then bolted both sides to hold the stab in place.

Before finalizing the forward spar bracket, the hinges have to be kept perfectly straight. I decided to use the rudder as my straight edge, because it will tell me if there is any change in the play on the rudder.

It worked great, and after ensuring it swung freely, I determined I need to fabricate a shim to go between the front spar and the bracket.

Next step is to fabricate the shim, and drill the front spar for the bracket.

Vertical Stabilizer

Drilled Horizontal Stab

GeorgeLeave a comment

This weekend I spent time getting the elevator horns drilled for the pushrod and the horizontal stab drilled and mounted to the fuselage.

Britney was in town visiting me this weekend so, of course, I asked her to help me work on the plane. She has been very encouraging and really wants to help on the project. So we got started by mounting the elevators to the horizontal stab on the bench.

Once we got the elevators lined up and clamped, we measured which horn was aft, and then removed the left elevator.

I measured and then drilled the hole for the pushrod, and then I fabricated a block to span the gap between the horns, remounted the left elevator and placed the block between the horns. This ensured that the #30 pilot hole was drilled perfectly perpendicular.

Once the pilot hole was drilled, I enlarged it for the AN3 bolt that will eventually hold the pushrod.

The resulting holes are perfectly lined up and perpendicular.

Once this was done, we removed the elevators and then positioned the horizontal stab on the fuselage.

We measured, and then measured, and then measured again. I clamped everything into place and measured one last time.

I then drilled my #30 pilot hole through the stab and then remeasured. After ensuring nothing moved, I final drilled it for the AN3 bolt and then inserted the bolt to prevent anything from shifting.

This is the underside of the outer holes after drilling the pilot holes. Edge distances for the longeron were right on the money.

I then proceeded to drill the remaining two holes, and fabricated the F-798 shims. Everything lined up and I did one final measurement, and it all remained perfectly aligned.

I bolted the forward bolts, used a 3/16th spacer to raise the rear spar to the right height, and then drilled and bolted the four holes to mount the rear spar to the fuselage.

Next up is the vertical stab!

Drilled Horizontal Stab