Lets prepare the final Part that is attached to the main Body...
the rear vertical Fin (Stabilizer).
This part is different in that it has a central mountain fold and two valley folds.
The mounting (glue) tabs must be folded outwards (valley fold).
So, score all fold lines in preparation.
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After assembling the Tail Fin, we will need to prepare the main Body to receive it.
This should be done sometime before you cut out the main Body part.
A slot has to be cut in the rear of the body, to receive the Fin from underneath.
But before we can do that, we have to finish the tail Fin.
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...cut out the Tail Fin part using a straight edge.
Its important that you cut it accurately.
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Edge colour the part...and then fold into the correct shape.
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Its important that the trailing edges line up neatly.
How everything lines up will be controlled by how accurately you cut out the part
and how accurately you scored and folded the part.
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Glue the two sides flat, lining up the trailing edges.
If there is a slight misalignment of the trailing edges, you may be forced to trim with a straight edge.
Once the glue is dry, you can fold the mounting tabs outwards at right angles.
Crease the fold to make it as sharp as possible.
Touch up your edge colouring if necessary.
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The Tail Fin slot must be cut wide enough to allow the Fin to fit freely,
but not so wide as to allow any extra space.
The slot is roughly .5mm wide...about the thickness of two layers of 65lb cardstock.
Use a metal straight edge to cut the sides of the slotted opening.
Cut the narrow ends of the slot using the pointed end of a sharp Hobby Knife.
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You can check the slot with the assembled Fin, to make sure it fits.
Insert the Fin from the back side of the model sheet.
If its too tight, you can cut open the slot a little more by carefully using a knife and straight edge.
Check the fit again...make sure it fits snugly, but not too tight (or too loose).
It is best to make sure the Tail Fin fits properly before you remove the main Body Part from the model sheet.
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