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Joined: 25 Oct 2003
Location: Canada, Nova Scotia, Halifax
|Posted: Fri Feb 13, 2009 5:13 am Post subject: Week 3 - Assembly, Attachment Points, Pockets, Bridles...
|Week 3 - Assembly, Attachment points, Pockets, Bridles and Framing.
This week we will cover assembly, pockets, bridles and framing of the Fled. At this stage you should have the following pieces.
- 1 x Body panel edge bound with longeron restraints and reinforcements attached.
- 2 x Wings edge bound on two sides with 1 corner reinforcement.
- 2 x Keels edge bound on two sides with 1 corner reinforcement.
- 4 x Drogue panels edge bound on the top and bottom.
If you don't have these pieces head over to week 2 to get caught up
Bridle Attachment Points
For the attachment points you will need a 14" piece of 1/2" gross-grain. Fold the it in half length wise and sew it down with a straight stitch or zig zag. You should now have a double thickness 1/4" piece of gross grain. Using half this piece form the tow point loop as shown in the diagram. I have used contrasting colors to help make it more clear. I attach the binding to the keel with a bit of double sided tape, then sew it down with a 3 step zig zag.
Cut a 1/2" x 14" piece of gross-grain
Fold in half lengthwise and sew
Cut it in half
Attach to keel corner folded like so..
This kite has only two seams holding all the layers of fabric together. Since there will be 4 layers of fabric in each seam we will use some double sided tape to hold everything in place until we sew the seam. There are many other ways this can be accomplished, so if this method doesn't suit you then do what ever you are most comfortable with.
The lower half of this diagram shows how the kite is assembled.
The following steps will illustrate how I get the body, keel and wing pieces to stay in that configuration when I head to the sewing machine.
1) Make a pencil mark on the back of the wing 18 9/16" from the top measured along the seam allowance. This will mark the position of the spreader tie-down/loop, and will also aid in pocket placement after the kite is assembled. Do this to both wings.
Measure down 18 9/16" on the seam allowance and mark
Measure from the edge of the fabric inside the edge binding, not the top of the edge binding
2) Lay the body of the kite face down on a flat surface. i.e. the lower dacron tunnel reinforcements should be facing up and the upper velcro and gross-grain restraints should be facing down.
3) Apply a strip of 1/4" double sided tape along the seam allowance at the edge of the kite (or to the inner seam allowance of the kite, I show both in the pictures below.) Make a 7/8" fold along the outside edge of the body to create the longeron tunnel. We are folding our 1-3/4" strip pictured in the longeron detail diagram in half. The 1/4" outside seam allowance should match up with the inner 1/4" seam allowance. (see photos below)
DS tape on the outside seam allowance
DS tape on the inside seam allowance
Fold over to form tunnel
4) Add a strip of 1/4" double sided tape to the folded over raw edge. That is to say it will be applied 3/4" from the newly folded edge. The pictures below should help.
1/4" outline of where DS tape should be placed
5) Place the keel along the DS tape as shown. (the keel in this photo is the black fabric, the blue wing shouldn't be in the shot, it's just trying to steal the spotlight ) Make sure that you consider which keel to use. If you want the reinforcement on the inside of the keel, then make sure that the reinforcement is facing down.
Left hand keel in placed along DS tape
6) Apply another strip of 1/4" double-sided tape to the edge of the keel that you secured in step 5 and attach the wing. The wing tip reinforcements must be facing up.
Left hand wing placed over left keel
7) You should now have the pieces stacked and secured as shown in the diagram below. Now sew all the layers together using a straight stitch. Since we used double-sided tape the seam tag will be stuck to the body on the back of the kite. Add another row of stitches here to keep the tag securely fastened to the kite body.
Assembly with double side tape locations shown
In order to make it easier to sew, I roll the excess fabric and secure with tape or clips.
The right hand wing-keel-body sandwich rolled and ready to sew.
Repeat the process for the other side.
Drogue Attachment points
The following steps will close off the bottom of the longeron tunnels and add our drogue attachment points in one shot.
1) Cut two 1" pieces of Gross-Grain and fold them in half.
2) Insert the open edge of the fold into the bottom of the longeron tunnel, about 1/4" inside the tunnel should suffice.
3) Sew a row of stitches 1/8" from the bottom of the tunnel. This will close the tunnel with the gross-grain sandwiched in the middle.
Cut Two 1" pieces of gross-grain
fold and place inside longeron tunnel, sew closed
Below are two ways of creating loops that attach to the back of the sail to hold the spreader against the skin.
1) Use a 1-1/2" strip of 1/2" folded gross-grain (as we did for the bridle attachment points) and attach it to the seam allowance centering an arch on the 18-9/16" mark we made earlier. It's easiest to use a spar to help get the size of the arch. I usually leave a little slack to make it easier to insert the spreader in the field.
Top down view of gross-grain arch
side view of gross-grain arch
2) Use a 12-14"" piece of bridle line or ribbon and stitch it to the 18-9/16" mark we made earlier. (The photo of this shows the line embedded in the seam but it should be sewn on top) Be sure to add a few stitches to ensure a good hold.
Pockets and Velcro Flap
I use a single folded pocket on one wing tip and a velcro sleeve and flap on the other.
You will need
1 x 4-1/2" piece of 1" wide webbing
1 x 1-3/4" piece of 1" wide webbing
1 x 1-3/4" piece of loop velcro
1 x 1-3/4" piece of hook velcro.
Prepare the pieces for the velcro sleeve and flap
Melt the ends of the webbing to help with fraying
Sew the loop velcro to the 1-3/4" piece of webbing
Sew the hook velcro to one end of the 4.5" webbing
Sew the 4.5" webbing over the reinforcement on the wing. Line up the center of the webbing with the 18-9/16" mark we made earlier.
the point should line up with the center of the webbing
Sew the 1-3/4" velcro loop-webbing sandwich to the 4.5" piece of webbing, Note: Only sew along the long edge as this creates our spreader tunnel
For the other wing tip we create a pocket by folding a 2-1/2" piece of webbing at the 1-1/2" mark. This creates a reasonably easy access pocket to secure the spreader.
1-1/2" of the 2-1/2" long webbing on the reinforcement
1" remainder folded over to form pocket, sew along edges only
Prepare the drogue panels, I usually make a light 1/4" mark down each side
Attach two sections of the drogue good-side to good-side, and sew along 1/4" seam allowance
repeat for the rest of the panels
Sew the last panel to the first panel to close the drogue
Now we need to add the attachment points. Use a 8" piece of 1/2" webbing folded in half length wise and sewn closed. Cut 4 2" pieces to form the raw material for the tabs.
It's the 4 tabs (applause)
Fold each tab in half and position it so 1/2" of the tab wraps around the seam tag
All tabs in place
Turn the drogue shoot right-side-out, and you are done
Each longeron is made from two 32.5" spars ferruled together with an internal .2400 solid ferrule. (if you are using Skyshark P series tubes). Slide them into the longeron tunnels and close the velcro flap. They should fit snuggly.
The spreader is built from three spars of equal length. The center spar has a internal ferrule at each end. This is handy when trying to sort things out on the and get the spreader installed.
To build the 3 spars it's best to measure your finished kite and cut to fit. There will be slight variations in how each person put the kite together. Most of mine work out to be 29-1/2" each. Add end caps to the outer spreaders and you are all set.
Here are the bridle measurements that are pretty much as the plan specifies.
Bridle 5x the height of the kite, I feel this is a bit long but you can experiment to see what feels right.
For the bow line, I use a 80" line with 6" loops at each end. This is attached to the spreader using prussic (sp?) knots. The knot constricts around the spreader and provides enough friction to hold the bow in place. To set the bow, flex the spreader and slide the prussic knots toward the wing tips.
Prussic attached to spreader
Kite guy had a good post on this technique here: http://www.kitebuilder.com/forums/viewtopic.php?t=5717&highlight=prussic
Except I tie the Prussics in hand like this: http://www.kitebuilder.com/forums/viewtopic.php?t=726&highlight=prussic
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