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Semroc - Swift BG

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JAL3

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The Swift BG is one of the new kits released by Semroc for NARAM 51. It is a reproduction of an old Centuri design. Although I have had terrible luck with gliders, something prompted me to get started on this one right away. It might be the one to break the jinx.

I ordered mine as soon as it was availible and in typical Semroc Time Warp fashion, it arrived almost immediately, even though Semroc was closed for NARAM. It was also production kit number 10.

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JAL3

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Construction began by locating the wing and gently sanding it in its balsa frame and then releasing it. Although the wing consists of 4 pieces, they are not yet cut apart at this stage. The only thing that marks the discrete pieces is a line.

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JAL3

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With the wing remaining in one piece at this point, the instructions gave two options for shaping. The first was to merely round the edges of the balsa and I was sorely tempted to go this route. The other was to try and sand an airfoil into the wing. Nothing ventured, nothing gained.

In effect, I merely rounded the forward and outside edges but I made an attempt to approximate an airfoil on the trailing edge. I drew a sanding block across the rear edge from one end to the other trying to guide the profile down to a blade. It turned out better than I expected but it is certainly nothing to brag about.

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JAL3

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The wing sections were numbered from left to right for later identification.

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JAL3

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A steel ruler was then used to guide a razor knife along the marked lines and separate the wing into 4 segments.

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JAL3

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The freshly cut edges of the wing segments were then beveled with sandpaper so that when canted, they would fit together better.

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JAL3

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The kit came with the pieces to construct a pair of balsa jigs to aid in getting the correct dihedral angle on the wings. They were removed from their parent material and glued together. They are identical except for one being a bit taller than the other. After use, they are discarded so there are no extra points for style here.

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JAL3

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A piece of wax paper was taped down to the working surface and then the inner right wing segment was taped flat to it. The tip of the outer right wing segment was then taped to the taller of the two jigs. With that done, a bead of white glue was run against the beveled edge and the two segments were pressed into place, allowing the jig to hold the pieces at the correct angle.

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JAL3

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A day later, the jig was removed and the end piece did not fall off. I took that as a good sign.

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JAL3

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The process was then repeated with the left side of the wing with similar encouraging results.

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JAL3

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The two wing halves were then joined together in a similar manner. One side was taped down flat and the other was glued into place using the shorter of the jigs positioned under the outer joint of the untaped wing.

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JAL3

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After another day to dry, the jig was removed and things were still looking encouraging.

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TheAviator

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Looking good there! Gliders are a lot of fun, and this one looks like a real performer. I suggest you go with a 1/2A3 or 1/2A6 if you want to be sure to get it back.
 

JAL3

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Looking good there! Gliders are a lot of fun, and this one looks like a real performer. I suggest you go with a 1/2A3 or 1/2A6 if you want to be sure to get it back.
Thanks.

Its going better so far than I expected. Of course it is a Semroc so I should have expected that.

The only recommended motors are the 1/2A6-2 and the B6-2. They skipped right over the A.

I'm not into the competition stuff and walking + arthritis + lazy middle aged fat guy = 1/2A most likely.

I just want to get one glider that sorta glides. Right now I'm 0 for 3 and I don't really hold out much hope for the Cosmos Mariner in progress.
 

TheAviator

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Thanks.

Its going better so far than I expected. Of course it is a Semroc so I should have expected that.

The only recommended motors are the 1/2A6-2 and the B6-2. They skipped right over the A.

I'm not into the competition stuff and walking + arthritis + lazy middle aged fat guy = 1/2A most likely.

I just want to get one glider that sorta glides. Right now I'm 0 for 3 and I don't really hold out much hope for the Cosmos Mariner in progress.
The reason (I believe) that they skipped over the A's is because all of the A's have too long of a delay (A3-4/A6-4) or too high average thrust (A8-3/A10-3). The 1/2A3-2 would be a perfect motor if you make an 18-13 adapter.

Oh, and you should expect a walk. One good thermal, and this thing could be in the air for several minutes.
 
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JAL3

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The reason (I believe) that they skipped over the A's is because all of the A's have too long of a delay (A3-4/A6-4) or too high average thrust (A8-3/A10-3). The 1/2A3-2 would be a perfect motor if you make an 18-13 adapter.

Oh, and you should expect a walk. One good thermal, and this thing could be in the air for several minutes.
That's a definite possibility assuming the initial flights go well.
 

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The tail boom comes in two main pieces. They were removed from the parent material and test fitted together. The fit was good and no sanding was needed.

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Some white glue was then put into the keyed joint and the two pieces put together and laid flat on the wax paper. A steel ruler was used to make sure the boom was straight.

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The next day, the boom was ready to be peeled up and looked fine. The jinx, if not gone, had certainly gone into hiding.

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There are two balsa strips, rounded at one end, intended to be applied on either side of the forward end of the boom. They provide some support on the side for the booster pod.

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A light layer of glue was applied to the boom and spread out for the length of the facing. A facing was then pressed into place so that it was even with the front edge and the top and bottom surfaces. It was allowed to dry like that for about 30 minutes. Some cheap plastic clams were used to keep it in place.

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When dry, the opposite facing was placed in the same manner, clamped and set aside to dry.

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The horizontal stabilizer was removed from its sheet. Sandpaper was used to round all the edges.

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The vertically stabilizer was similarly removed and sanded on all edges except for the bottom, which was left flat.

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With the tail pieces sanded and test fitted, a line of glue was applied to the base of the vertical stabilizer and it was fit onto the horizontal. The assembly was then set flat on the wax paper and a steel ruler was used to insure a right angle.

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After drying for a day, the boom was unclamped and examined. It seemed in good shape and the pieces were mostly in alignment. A bit of light sanding took care of evening up the edges.

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JAL3

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With the edges even, I then needed to taper the leading and trailing edges of the facings on each side. I used a sanding block and tried to gently take the material down to a knife edge.

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The tail assembly was placed at the end of the boom on the flat side. I had a sinking feeling about this because no jig or template was provided, only an admonition to make sure it was placed straight. I used white glue and eyeballed it the best I could and checking the angle with a steel ruler. I tried to make sure that it was straight and level. The feeling of impending doom was palpable.

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The next day, it was time to place the wing. A mark was made 1/2" back from the side pieced and the wing was glued into place with white glue. The trepidation factor was even higher than with the tail because I know from experience these things just never turn out, especially when there is an angled surface involved. The feeling of impending doom returned with a vengeance.

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JAL3

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Even though I knew I was doomed by this point, I figured I had gone too far to back out now and I got to work on the pod hook. It was in two pieces which needed only to be glued together. I used white glue and clamped it.

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