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Tube Fin Fletching Jig Construction

Tube Fin Fletching Jig
  

The instructions below are to help you to construct a jig for mounting the new tube fins at a consistant angle so that the bolts fly straight and true to the intended target. Please see these instructions for how to assemble the tube fins themselves.

Tools

Supplies

1" Drill bit

1" Dowel

3/4" Drill bit

3/4" Dowel

Chop Saw

2x6

Drill Press

2x2

Ruler

1/2" thick scrap

Cut an 8" piece of 2x6 and mark a line across the center and another 1.25" to each side of center.

Mark the center in the other direction, then above center by 7/16" on one side and below center by 7/16" on the other side.

On the bottom edge of the end of the board measure in 4" from the corner nearest the off center marks made in the last step. Repeat on both ends.

Drill the center 1" diameter hole vertically, but not completely through the board, approximately 1.25" deep.

Place the 1/2" thick scrap under the block so that it is parallel with the long edge of the board. Then drill a 3/4" diameter hole completely through the wood. Reverse the angel for the other side.

Cut a 14" piece of the 1" dowel and two 8" pieces of the 3/4" dowel.

Permanently glue the 1" dowel into the center hole.

 
Using the Jig

As with most things in archery there is no "wrong" way, so long as you can consistantly repeat doing it exactly the same everytime. The goal is to mount the fins at a slight angle, and have the fins on all your bolts have the same slight angle.

Place the fletching jig way off center in a vise and place a ballista bolt shaft over the center peg.

Run a piece of strapping tape through the premade tube fins and push the 3/4" pegs through so the front of the peg is just at the front edge of the short side of the fin.

Push the pegs through the side holes, use the piece of 2x2 as a spacer to keep the fins the same distance from the back of the bolt. Tape around the bolt across the tape sticking out the top end of the fins.

Press the tape sticking out the bottom end of the fins onto the shaft. Then pull the pegs out through the bottom of the jig.

Finally, tape around the bolt across the tape sticking out the bottom end of the fins. Reset and repeat for the rest of your bolts.

If you are looking for how to construct the other end of your ballista bolt here are  two links to articles on ballista tip construction. Any of these instructions will create tips & bolts that will pass the new rules.  LINK A  LINK B

Written by Baron Jonathas Reinisch

(Permission is given to copy as long as credit is given to the author)

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