PLANS DE CONSTRUCTION D'UN CERF VOLANT

DESOLE POUR LES NON ANGLOPHONES !!!!

Copyright

The copyright of the Raaseri plan (except the photographs) is owned by Simo Salanne.

You are granted a permission:

You are not allowed:

Raaseri logo is designed by and copyright of Peter Ulfheden.

Copyright © 1994...1997 Simo Salanne
Version 2.2, 1-Dec-97

Contents

Raaseri is a high performance dual line stunt kite designed for individual precision and ballet flying. It flies rather slow and thus can be used for pair and team flying, too. Raaseri will axel and do some other "radical tricks" but it is not a genuine trick kite.

For more background information read Raaseri Story.

If you are not familiar with basic stunt kite construction techniques, I suggest you to study Stunt Kites to Make & Fly, by Servaas van der Horst and Nop Velthuizen. ISBN 90-6868-052-8 Available from kite shops or Vlieger-Op.

Drawing

The dimensions in the drawing are in meters and from a flat, unassembled kite, when assembled e.g. the wing span is smaller than in drawing.

Materials

The table below lists the materials I have used for different versions of Raaseri. I have not experimented with any other material combinations (except SkyShark 2P and Response Zero for ultra light one:-). You may replace any of the stuff with something else, just don't ask me how it works. I don't know and I don't like to quess.
  Raaseri-L Raaseri-M Raaseri-H
Sail Icarex P31 Icarex P31 Icarex P38
Leading Edge Spars 3P/Res12 RCF-7 RCF-7
Spine RCF-6 Ultra RCF-7 RCF-7
Upper Spreader RCF-6 Strong RCF-7 RCF-7
Lower Spreader RCF-6 Ultra RCF-7 RCF-7
LE tunnel Icarex PL62 Dacron tape Dacron tape
Standoffs CF-2 CF-2 CF-3

Frame

SkyShark 3P was selected for the leading edge (LE) of Raaseri-L because it's wrapped structure takes bending stress without breaking more often than pultruded Exel RCF-6 Ultra. Actually, I have not broke any of 3P in ground work. Even better leading edge spar for light winds is a combination of 3P (nose part) and Response 12 g (wing tip). Tapered Response is more flexible but the thinner end is stronger than 3P.

However, if you have to cut SkyShark spar, you loose the re-enforced end(s). That's why Exel RCF-6 Ultra was used for spine and lower spreaders.

Exel RCF-6 Strong for the upper spreader in Raaseri-L was not selected for strenght reasons, but to move the center of gravity forwards. Same effect can be achieved by inserting some 4 mm carbon or glassfibre rod inside of Exel RCF-6. Originally I had the upper spreader made of Exel RCF-6 Ultra. When I flew Raaseri-L and walked down to gain field, it had tendency to lift it's nose. That's why I had to add some weight. The balance may vary depending on the construction details, e.g. on the weight of cross and LE connectors. If you are lucky, you may need no rebalancing and can use Exel RCF-6 Ultra as upper spreader.

Exel RCF-7 is very nice spar for medium and high wind kites; it's stiff, strong and has attractive price tag. The extra weight - compared to 6 mm sticks - gives more inertia for the kite and e.g. makes Raaseri-M to axel much easier than Raaseri-L. I haven't broke any of Exel RCF-7s in my Raaseris. The leading edge of Raaseri-M and Raaseri-H is made from one piece of 1.65 m long spar; no weakening joint in the middle! If you don't have Exel RCF-7 available, SkyShark 7P will also do well in Raaseri-M and Raaseri-H. Beman Ultra Light 21 is also a very good choice.

If you are not going to build the whole set of Raaseris, Exel Extreme-6 or SkyShark Vp frame will make a good all around kite for 3...8 m/s winds.

Although the drawing gives the lenght of the upper spreader, don't use it! Instead assemble the kite and find the lenght of the spreader by trying a piece of stick in it's place. You may need to adjust the lenght to find optimal tune - it's recommended to start with a longish spreader and going towards a shorter one.

Sail

Construct sail panel templates according to the dimensions in the sail plan.

sail plan

Templates can also be made by printing a postscript file on a postscript viewer/printer:

Mike Emery has converted the templates to KiteFlight/PLOT format, which supports dot-matrix and ink jet printers without postscript.

Postscript file prints multiple A4 (or legal) size sheets, which should be glued together to make 1:1 size templates. There's a 25 x 25 mm grid and page coordinates (0/0 being lower left hand corner, 1/0 right to it and 0/1 above it) to help positioning. Before cutting your fabric check that the spine lenght of your template is about 110 cm as in the drawing. Some people have got "maxi" version templates from their printer (!?). Have a look at the beginning of file template.ps, there's a line:

/mag 9.5 def

which defines the scaling of templates. If your first printing results templates e.g. with spine lenght of 131 cm instead of 110 cm, you should change the ps code to:

/mag 110 131 div 9.5 mul def

If you then want to make a 3/4 version of Raaseri, just change the ps code to:

/mag 3 4 div 110 131 div mul 9.5 mul def

Scaling does not affect to the grid size, it will stay 25 x 25 mm. In the end of template.ps file there is a comment line explaining how to select the pages, which are printed. When you adjust the scaling you may need to play with this part of the postscript if you want to avoid printing a few "empty" pages, having just the grid on them.

Templates are of 'final' size of the panels. You have to add your favourite seam allowance and fabric for the spine tunnel to the templates. "#" like symbols indicate the nonsquare grain/bias direction for Icarex P-31.

I sew first all left side panels together and right side panels together. Then, taking care of the symmetry, sew them together by making the spine tunnel. spine tunnelThe purpose of the spine tunnel is to the keep sail centered and prevent the sliding in tight turns. If you prefer simple solutions, forget the spine tunnel. Next the trailing edge, and then leading edges. One thing in the order is important: you have to sew all the panels together before the trailing edge, otherwise you can't get the tensioning line through the TE hem!

Trailing edge (TE)

When sewing the trailing edge, leave room in the fold for tensioning line. I have used a thin 2 m long piano wire, which is folded at the middle, like a sleeving tool, to pull the tensioning line inside of the trailing edge. 150 kg spectra or 75 kg polyester is suitable line material. Leave small loop at the tail and smooth out the trailing edges towards wing tips. Sew the tensioning line to the sail from tail to the standoff connection point. Leave it floating from standoff to wing tip. At the wing tip attach 3-4 cm long loop of 75 kg Dynacore with Prusik knot to the tensioning line. Prusik knot is used to adjust the tensioning. A rule of thumb is: if the trailing edge makes some noise in straight flight, tension more - if the wing tips start to vibrate, tension less. Raaseri can be tuned to fly silent, except in very tight, inside of wing tip loops, some noise might occur.

Leading edge (LE)

Template dimensions expect you align the LE of the ripstop with the fold on LE re-enforcement tape. As the re-enforcement tape does not stretch, the LE sewing is not an easy task because of the curved shape.

Use zig-zag stitch on LE to sail seam.

If you have problems to get a smooth alignment, make the re-enforcement of four tape pieces as decribed in the following drawings.

The curved part from upper to lower spreader is made from two pieces of tape like this:

Leading edge from nose to upper spreader and from lower spreader to the wing tip are made of one folded piece of tape.

Sail tensioning.

I have two sail tensioners along the spine. One loop of 3 mm bungee cord from the loop of trailing edge tensioning line at tail to the spine end cap. This is tensioned 'lightly', just to keep the lower part of the sail in shape. Above the cutout (for cross connector) an U shaped piece of 150 kg polyester line is sewn to the back side of the sail about 5 cm lenght. The lower part of the U, below the cutout, should be about 10-15 cm long and is not sewn to the sail. The upper part of the sail is tensioned by another loop of 3 mm bungee cord pulling the U towards the spine end. Actually, you can combine the elastic loops just to one loop going from sail tail, over the spine end cap to the "U". Place the U and the knot on the bungee cord inside of the spine tunnel. That makes very neat spine end - no knots where flying lines can get wrapped. This construction avoids stretching the sail around the cutout.

Wing tips are tensioned along the LE by a bungee cord. TE as described in Trailing Edge .

4-leg cross shunt Bridle

Bridle I make the bridle using separate pieces of line for each 4 + 4 bridle legs. (Image size 3 KB) Tow point end has an overhand knot, the frame end has a separate loop connected with Prusik knot. Sliding Prusik knot allows to adjust each leg independent of the others. When locked, Prusik knot takes the load without sliding. The ends with Prusik knot are connected with a lark's head around the frame and the ends with over hand knot will be tied together with a loop of same (or stronger) bridle line. 75 kg Dynacore for Raaseri-L and -M, 150 kg Dynacore for Raaseri-H. I cut 90 cm (for the haul) and 25 cm (for the loop) long pieces of line.

The shunt leg should be tuned so that in lower part of the wind range it is loose. When the wind increases and lower spreaders bend, the shunt leg should get tight and take part of the load before lower spreaders break. Bridle dimensions in the drawing are measured from an assembled kite and can be used as starting point to tune all three Raaseri versions to your taste. When you have found the tune, you can tidy the bridle lines by cutting the extra ends away.

I have Raaseri-L tuned lower (towards tail) than Raaseri-H (toward nose)!

Standoffs

In Raaseri-L and Raaseri-M 2 mm solid carbon rod is used for standoffs (whiskers). Standoffs are so long that they deflect about 20...30 mm from straight line in the middle. In Raaseri-H 3 mm solid carbon rod is used. The standoffs are just long enough to make the sail tight, i.e. no remarkable bending.

Vents

 The purpose of vents is to pass some of the wind pressure through the sail and reduce the pull and speed of the kite. Vents are used only in the heavy wind Raaseri-H.

I was looking for a stronger mesh (gauze) than the one used e.g. in Flexifoil front, and by accident invented to recycle sun screens from my car to the vents in kite! Sun screen mesh is pretty tight and does not stretch at 'diagonal' direction. However it is porous enough to reduce the pull of the kite in high winds. Panel 3 is mesh in Raaseri-H. Connecting mesh and ripstop needs rather wide seam. I have used 20 mm wide flat fell seam with three straight stiches and one 3-sticht zig-zag.

FAQ