#KITE SHAPE GEOMETRY SERIES#

It's no longer a standard delta wing, no longer a single isosceles triangle, no longer standard, and to relate experimental non-standard designs to other known designs meaningfully, the towing points must be expressed in such a way that they can be compared and duplicated. What if the center spine is extended beyond the baseline, or the wing tip is raised a short distance above it? That is, bits are either tacked on or chopped off the true delta wing. They might have fringed, flapped, straight and scalloped trailing edges, depending on their size - the smaller the kite, the more they need trailing edge drag and vice-versa.

#KITE SHAPE GEOMETRY SERIES#

For example, imagine a series of kites, all the same design with identical frame proportions, but each one is a different size. The towing points are trickier to calculate for scalloped trailing edges, but, in general, trailing edges don't present any major problems. Thus a standard delta with a scallop is still a standard delta - the end of the spine and the wing tips are on the baseline. Using proportions enables easy scaling.īetween the end of the spine and the wing tip the fabric can be cut in a straight line, but it could also be scalloped or have extra material as a flap or apron (as they're sometimes called). It is based on spar length, which is a proportion of the leading edge. The spreader attachment point is measured up from the wing tip along the leading edge. This defines the 'standard delta' wing (with straight trailing edge, a true delta wing), and the fin is based on a few simple proportions. The baseline is at a right angle to the end of the centerline. Working on one wing half, I mark the end of the centerline, and then measure perpendicularly to the wing tip along a baseline using a pair of sufficiently long straight-edges and a large set square. Whether doing a scale drawing of a new design on paper or a full-sized kite on fabric, I begin by marking it out along the centerline, starting from the nose.

That is, if it didn't fly the first time. One only needs this way of looking at a delta, as distinct from the clipped wing tip version, if the materials at hand require it.

The spars would be a different length and the spreader pockets located differently. As a result, they are usually good over the widest wind range of all deltas.Įxtending the center spine achieves the same wing as clipping the tips, but with subtle differences. Their wing spars need to be stronger, and therefore heavier, thanks to the extra mass of flapping fabric and the associated drag. The wing spars are thinner and lighter because there is lower load from drag for them to handle.Ĭlipped wingtips add a flap of fabric on the trailing edges that increases stability over a better wind range at the expense of a few degrees of flying angle. Scalloped trailing edges reduce drag and lead to steeper flying angles, but they also reduce stability and require a high level of precision in both design and execution. It is possible to improve on one or another aspect of the basic delta's flying qualities by clipping the wingtips, extending the wing at the spine, and scalloping the trailing edges. The kite flies very well without excessive flexing.Īfter learning the process of perfecting a design, the next step might be to look for small ways to improve on the basic delta, or at least try something different. Taping the wings has controlled stretch, and the frame is ideally suited to the wings. Note how smooth the 13 footer in the photo is. An earlier version may become a favorite light wind kite as well. Usually the previous version (about 2% larger) is the best all round flyer.

Follow with smaller and smaller versions, in stronger and stronger winds, until they're unflyable. After a series of test flights in as wide a range of winds as possible, make a smaller one, scaled down about 2%. The process starts with a light wind prototype, or test kite, with fairly long, bendy wing spars - in other words a light frame. It's not necessary to go beyond the basic delta, either, for the performance and handling of a perfected standard delta is beyond reproach and definitely worth striving for. It's not even necessary to calculate the wing's area.

For this the mathematics are equally uncomlicated. The first task is to perfect the basic delta, the pure triangular shaped kite with the simplest geometry: an isosceles triangle. Starting with a blank sheet of paper and a pencil, the quest begins. Home - Contents - Catalogs - Line & winders - Falconers section Basic Delta Types Designing, scaling, comparing and evaluating experimental delta designs Perfecting a delta design

Kite shape geometry