Mail Me if you like to add a tip here.
- Kite Parts and where to get
- Joining Plastics
- Kite Repairs
- Plastic (Vinal) Tubing
- Sail Materials
- General Plastics
- Kite Line
- Types of Kite Line
- On Field
- Kite Height
- Line Winders
- Tie Down Stakes
- Line Laundary Connectors
- Scientific Principles
Where do you get your kite making materials?
I get the fiberglass and carbon fiber spars from a local factory that makes fishing rods! They get the straight rods from their sister factorys that handle those aspects.
For Ripstop sails, I usually use a LOT of ripstop offcuts curtisy of a number of sail makers in the area. Usally these consiste of long thin triangles about 50cm wide at the base. I also buy larger lengths (couple of meters or so) off their rolls. Warning, take off your shoes before proceeding on their work floor!
For larger projects (like beach balls, or a lifting parafoil, the later I have yet to attempt) I mail order from a supply warehouse, who deliveres the next day!
Other bits and pieces I get as needed, and often use alturnatives. Clear vinal tubing from the local hardware, which I also use for dowel, braided nylon builders line (for replacable kite bridles, this part is most commonly damaged in regular use), and contact cement (for home made ripstop repair tape in special colors); plastic bags and Bamboo BBQ skewers (smaller kites) from the supermarket; Ripstop repair tape, and double sided tape from a marine chandlers; Nylon line (fish netting line) from one rope place or a fishing tackle warehouse; spectral core line (for large kites) from another; dacron line (mid-range kites) from a kiteshop; solid brass rings whenever opportunity presents itself; hotglue, white wood/craft glue, photo-mount spray glue (for applique), ribbons (for spar tie points), eyelets, and sewing thread from a fabric/craft shop. Lastly I also use fiberglass washers from a automotive shop for use as axil bearings on my UFO kites.
The list of bits and pieces I now use regularly has become huge. Often I just happen appon something and thing.. "hmm that could be useful" and get a few for my toolbox. Some things (like lighters for cutting nylon line) I just seem to find thrown away with lots of gas left in them (only ever bought one once, and I currently have 5 working lighters!)
I think that should about do it! :-)
Here is how I hem...
The kite skin is cut to the exact size required (no hem allowence added.
I cut off a strip of ripstop (I don't bother with any fabric bias) in the desired color (usally black) about an inch (25mm) wide. I then straight stitch it to the kite skin along the edge less than 1/4 inch (5mm) from the edge (does not need to be exact).
hemming strip main kite skin ___________ ___ =============================!=== ^---- sew straight stich here
_______ (______ '. ====================!==== | ,------ | '-------' ^._.^-------zigzag stich to lock in place
If you increase the width strip of material (bias tape or otherwise) you could then probably insert a dowel into the edge. For delta kites you should use a dacron strip for the dowel pockets to prevent wear and tear on the leading edge. Particularly on stunt kites.
If you would like other hemming details using bias (or un-bias) tape have a look at the plan for Art&Fly Nasa Parawing, which uses variations on this technique extensivally for kite building.
Another is to use small pieces of double-stick tape to hold the layers together in the center. These are easily removed latter.
I myself prefer to spary one side (the back) with a light photo mount. This sticks the pieces together but still allows you to reposition them before you start sewing.
The solutions are usally either some sort of tape, or heat sealing.
See Plastics below for more general discussion of the various sorts of platic and their properties.
All Mylar kites I've seen have been taped with 3M / Scotch tape (the matt finish stuff)
I used 2' wide clear package sealing tape. It held nicely for 3 years. I don't know beyond that because the mylar finally ripped and I had to throw it out. BTW, the same tape did well for repairs until there got to be too many of them.
I have found that 6mm wide double sided tape which you can get from the marine shops great. This has a paper backing so you can lay out the tape put the edge of the myler or plastic to attach over the tape, then pull off the paper backing. Only the glue is then left behind.
I have now made two circoflex rings, each in under 24 hours of total work, using this method. The leading edge spar (already taped into a very large loop), and trailing edge leech line, can be inserted into the pockets as you are folding the mylar edge and pulling off the paper backing of the tape from between the material, sticking the two parts immediately and closing the edge pocket.
The result is a clean neat finish, and after the leach line is pulled 10cm or so shorter, both edge pockets are completely closed, leaving no outside openings for dirt and grim to get in. It also seals the mylar edge stopping any chance at rips, the bain of mylar!
For holes to attach bridle lines, I use thick all weather tape which I apply to the holes position on BOTH sides of the mylar, which prevents rips. I then use a paper or leather punch to make a nice neat hole though both the plastic tape and mylar. This hole is large enough and smooth enough to prevent rips starting, and tearing accross the mylar. These holes are also a good idea to the ends of any slits (such as required for UFO construction) or sharp internal corners.
-- Anthony Thyssen
I use a fibreglass fabric (as used for car repair) for heat protection and a 100W iron to "melt" the sheets together. A 100 Watt+ iron is perfect because the fiberglass is very "heat consumptive". After a while the welding time should be reduced due to the fact that the glass heats up.
The fibreglass spreads the heat so that there are no problems with burning the material. No rips since 3 years! Because of tension problems - wind can be very powerfull ;) - the seam of a kite should be made as dottet line. I recieved the best results with approx 3 welding points per inch. Double seams are better for high power kites. That is two rows of dots..
o o o o - o o o o o _1/2" |1" |
The connection is even suitable for gas-baloons (H2 gas)! I weld blimps in one continous seam and seal them with a Polyurethane spray afterwards. That works on kites too.
A Friend suggested ripstop tape, of which he only has black! (the torn panel is purple) He said if I cut out a nice pattern from the tape and stick it on back and front, no one will know theres a tear and it will look like a deliberate modification!
Apply sellotape to one side as a temporary holding measure.
Now, seal the join with Superglue.
When dry, remove the sellotape, admire the invisible repair and pay homage to Mr Benson.
Create a patch with the same ripstop material and contact cement. See Puppet_Kite_Cemetery #190
PS: Small toothpaste-size tubes, of contact cement is available at any hardware store.
I've successfully used white ripstop tape on the back. The repair still holds up after kite has seen a lot of beating.
OK you can see it when it's up close, but is near as damded clear then flying, so your original colour shows. I only carry white for this reason.
I made one of these (four corner kites), using the proportions in Jim Rowlands's "Big Book of Kites", and I could never get the thing to fly well. It was always very unstable.
Anthony Thyssen replies...
I had trouble until I figured out one small detail. The front of the kite is far back compared to the side bracing, as such the bridle attachments are on different levels, unlike most other 'flat' or 'box' kites. This makes bridling very awkward and weird.
You have to bridle it so that the center spar (in the spar pocket) is almost but not quite perdendicular to both the bridle line and the flying line. IE: the bridle line to the front point of the kite is much longer than to the side cross spars. (See the photo)
HINT: The flying line will, if you continue it though the bridle point, pass though the exact center of the kite, and if bridled correctly it should make make an angle of about 70 degrees (110 degrees) to the center spar itself, at that center point.
This is basically true of almost ALL flat surface kites including box, dihedral angle kites etc. Of course finding the center point (which is surface and weight related) for some kites can be difficult. Delta kites springs to mind as one example.
Cable ties, 19 cm, 100 per package are sold at wamlmart. They are very light and extremly strong. I use them on my kites instead of key rings or beer can tabs. My "blu max" delta has three loops to alter the center of lift if necessary. I use "eagle claw" barrel swivel safty snaps to secure the kite line.How do you determine the center of lift on varity if sail configuration besides guessing and dorking a kite? Anthony's Reply...
I thought I'd give you a tip on working with plastic (vinyl) tubing: The easiest way to put holes in it is with a short piece of brass *tubing* just like you would a drill bit. Various diameter tubing is available at most hobby or hardware stores. Just cut a piece about 2 inches long (... errrr this is Australia, make that 5cm long ;-). Put it in a drill and spin the 'cutting' end against some sandpaper to give it a sharp edge. Using it like you would a drill bit you can cut perfect circles through vinyl tubing without distortion. It's quick too. I made 36 connectors for a multicell box kite last weekend in about 10 minutes. I use this method on all my stunt kite fittings. Give it a try....
Thanks for the tip, though 3mm fibreglass does not really need this technique (for the fibreglass tetrahedral kite) as you do want a good tight fit. However for larger spars such as 6mm dowel (... err for americans 1/4 inch dowel ;-) a 5mm hole maker such as this would be a great help. Thanks for the tip.
Alturnative: A leather punch which has a dial to select hole size is even easier for making holes in plastic tubing!However cutting a hole in just one side of a plactic tube is not as easy. For that you should fold the tube in half, and then slice a hole using a shapr crafting knife. this can take a bit of practise to get the desired hole size.
Just built a 10 ft. gusett delta. We were positive it was extreamly well balanced...but it turned out to be very much a left handed leaner. We already finished off the trailing edge & didn't want to tear it apart.
What we did to correct this was to simply put an adjustable balance on the spreader bar. A piece of metal tubing that fit very well & held in place with surgical tubing, adjusted out to the right side till it came into balance.
Verlin Martin -- Delirious Delusion Kites
When someone tells me to go fly a kite I say
Giving the sails of a kite a 'angle' is not required in a kite, but it does improve the kites performance greatly. Even airplanes have a slight upward 'angle' to their wings. The following are some of the ways this can be achieved...
By breaking a kites cross spar in two in the center, and putting the ends in a angled tube, the spar is permanently angled (such as used on small airplanes). See El-Cheapo Diamond Plan for links and methods.
Alternatively you can either give a cross spar a permanent curve (EG: letting soaked wet dowel, dry in a vice), or by strecthing a string from one end of the spar to the other (like a bow and arrow). This is very typical for 'rokakkaku kites' for example.
When a kite sail fills with wind, it billows naturally into a 'diahedral'. Of course this only works if there is wind in the kites sails, if the wind drops or is too light a kite can loose its 'billow' and become unstable.
Indian fighter kites uses sail billow to achieve their manoverability. When the string is pulled, the sail billows and the kite flys straight in the direction it is pointing. When the line is loosened, the 'billow' disappears, the kite becomes flat, and it spins around radipidly on the spot.
Part of the Design...
Some kites have the wing angle set as part of the kites design. For example a "Cody Manlifter" is a very stable (for manlifting at the turn of the 19th centery) as it has some very very large angled wings built into the design of the kite.
Crease in sail...
For miniture/micro kites, where forces as ultra low, a crease in the sail is often all that is required to make the sails angle very nicely. But this would only work in larger kite if you could fly sheet aluminium in cyclonic winds. So is not practical in 'normal' kites.
The only cheap or local source I know is to ask at 'sailmakers' (look in the phone book) and see if they will sell you some off the roll (Make sure it is 3/4 oz ripstop).
Also if buying some ripstop they will usally allow you to 'dive' into their ripstop scrap bags. Here they have pieces of ripstop from a meter square or long LONG triangles cut from the edge of their sails. These are too small to be useful to them, and thay get lots of such off cuts, but for kite makers they can be ideal.
The long triangles are great for applique and if cut accross the long strip and pieced together, interesting designs can be created such as in my Mini-Circoflex Kites...
Use Waterproofing to stiffen soft ripstop!
Waterproofing is a product I fell upon very accidently. When you by a inexpensive (cheap) tent they generally have a ripstop nylon bottom and t will sweat water at night when water gets on the ground. To solve this problem, head out to your local (large) sporting goods store. The stuff comes in a small paint can and looks like varnish in the can just a little bit thicker.
Take a paint brush and paint material on rip stop backside. The stuff drys to a fairly stiff finish, does not let water thru of any type, and makes the material very stiff. It dosn't add hardly any weight, and closes all the poors in the material. The material does wrinkle a bit, but a very quick hot iron takes care of this problem. It also shrinks just a bit (not enough to hurt anything) but this does go away. Look at a camping sporting goods store in the tent section, also very good for seams and zippers.
One of my favorite tricks is using mens and womens suit lining for sailcloth. I get this material from $2 Fabric stores, selling bolt ends and remnants. Once sewn and sprayed with polyurethane, 50 cents a running yard at 54" wide can be pretty affordable when one loves bigger kites!!!
The polyurethane I use to seal the nylon is nothing more than plastic spray (99 cents a can at times) applied to the finished product (kite) and let dry. Be sure to test a patch of your material first!! Sometimes it takes more than one coat, (I help seal the pores along by using a 4" paint brush) but it's not needed very often. I also hit the backside of all seams to help seal and prevent loosening of stitching. Just apply and let it dry for a full day.
Hope this makes bigger kites more affordable for more people.
-- Bill Painter
Tyvek or 'Spun and Woven Olifin', is amazing material for kite building. This is a paper like plastic. You can Sew, Glue, Cut with a knife or Scissors, Paint, Applique ripstop on it, and lots more. But the material will not rip very easilly (more like near impossible!), has absolutely no bias (stretch) at all, and doesn't fray either.
The only disadvantage I have ever found is that it is heavier than ripstop, and generally only comes in plain white. Also as it is a plastic it does NOT dye very well (a dark red dye only comes out as a light pink).
Best way to decorate is to paint it. The paint does not have to be anything special, just cheap poster paints from the local news agents will be fine and you can be very creative. For example the photo to the right is my kite messager sail (ferry) on which I painted a dragon. The tubes of poster paints 'cromacril' can also be seen.
Ordinary wood glue also works very well. particularly for edges hemming, enclosing a leech line such as for Rokakkus. For spar pockets of deltas, sewing the pocket is better so you can still add and remove the side spars.
As the material has no bias, you can cut it to any shape and in any orientation that is convenent, and you only need a single fold, glue or sewn down as a hem. Actually you don't even need that as the material doesn't fray, but it still looks neater, wears with time better, and reinforces the edge from the small amout of stretch that can occur.
As the material doesn't fray, loose flapping sails can be created without problems, things like feet, tenticals, streamers, frills, or a fringe is not a problem as all. Just cut out the desired shape when cutting the main sail, or glue extra peices to the kite later.
For a simple example look this photo of a FedEx Tyvek Envelope Diamond Kite, by Audrey & Whye Keet.
I thought tape or glue was the only way to fuse the plastic, however I tried a battery operated ($5.00) plastic bag heat sealer which worked fine. It looks like a stapler; the sides of the bag are fan-folded to get to the center of the bag. It takes some practice to get it right. I did try it on mylar, which does not seen to like heat and tends to rip.
Anthony I have found that while scotch or magic tape will join polyethelene plastic (shopping/garbage bag plastic), the strechy nature of the material will still tend to work the tape loose if a spar of somthing is underneath. Scotch/Magic tape however retains their stick so a quick re-seal with your fingers before launching is all that is nessary. Tape used to along the loose edges of the kite does not have this problem and prevents the plastic streching here.
Note that heat sealing only seems to work for nylon and polyethelene plastic. Mylar (polyester) with or without the silver aluminised coating will not heat seal, but tape (doublesided or scotch) will stick to it even better. Also as the material does not streach (though will easilly tear) so tape will not work loose as it does for shopping bags.
The biggest problem I have is that sand, dirt and dust, will work its way into tape and eventually break the join. Of course that is not a probelm with a hot join or welded plastic.
You can tack shopping bags to plastic straws with a soldering iron with practise.
I use a 50 watt iron (with a pointed tip), but don't drag the tip.... I tap it very quickly to the surface of the film steached over the plastic straw, making small dots 2-3mm apart. If you drag the tip of most any iron, the sheet melts and separates from the work surface. Pracitise a bit with some scrap and you'll see what I mean.
I made a 4-cell tetra using 24 straws, (6 per sail) and the sealing method above. No separation as yet.
Anthony I have tried this with my 24 Watt soldering iron. and never got a good join. Probably it is not hot enough for 'taps' and too hot to hold on the material to get more heat.
Addendum: From the later emails added to this page, it seems that to do ANY form of heat seal it is vital that you use some sort of non-stick, heat resistant material between your hot surface and your join. Without this the method will just NOT work. Oven cooking paper should be ideal for this. It is probably what I was doing wrong.
About a plastic heat sealer...
The unit was purchased in some discount store, possibly Bradlees, or some other store I cannot decipher from the price tag. Anyway it is like a stapler; uses 4 AA batteries; and has fiberglass ribbon covering a single wire as a contact surface that is a quarter inch by one half inch in size.
If still interested in finding one, the Company is Emson, item #2307BL, made in China for E. Mishan & Sons Inc. Distributor, 230 5th Ave., NY NY 10001. The small contact area requires a sliding action over the areas to be fused. We found it difficult to control the speed to pass the unit over the kite material and would suggest spending the effort building a unit that is more adaptable to various materials and applications.
You can use the same set up to weld plastic garbo bag together, just use a oven bag over the plastic to stop the tip of the soldering iron perforating the plastic your trying to weld. Good luck!
Malcolm Dick, Kite Flyers of Tasmania
Made another "discovery"!!!" Paint stores (Dunn-Edwards in this case) carry a plastic drop cloth for painters to cover floors and furnature. It is a translucent plastic with a waxly like feel, and a consistancy , like shopping bags used at grocery stores.
It is VERY TOUGH STUFF!! Not quite the shopping bag thickness, but at .7 mil, it is VERY usable as sail material. The roll has the plastic folded on it a few times, which after unrolling and unfolding creates very very wide plastic sheets. It is available in rolls 6 feet wide by just over 100' long at only about $15.00 (US) per roll after taxes here in Phoenix, That equates to 2.5 cents per square foot!
2 ea. 4 foot x 1/8" dowels made a sled kite that flew in nearly dead calm air. It will fly at walking speed, and so did a little 12" sled I made the next evening....
One tip- if you are making multiple or larger kites with this film, it is a bit sticky with static electricity. Use this to your advantage and literally "hang it on a wall" to do the drawing, tracing, or even cutting if you can. The old half view (folded in two) works well as both sides can be cut at once for a perfectly even and balanced sail. Leave it on the wall to add the filament tape, dowels, and reinforcement!! Lot easier than bending over a table or on the floor..
-- Bill Painter 8O)
Anthony's Reply... The above was modified by me after further talks with Bill. It looks like the material is high density polyethelene sheets (shopping bags are low density polyethelene). This will streach slightly, but the material is tough, the streach will slowly recover. It does tear but only after lots of strain but does not easilly rip, that is tears do not progress.
All weather repair tape also uses the same material as the tape backing, comes in a wide rolls, with a glue which stick well to the plastic, does not age, is just as clear as the original sheeting, and is water proof! The perfect tape for bonding this material.
Unfortunately while very very strong the material has an annoying habit of ripping right across the kite in a split second, from a small puncture or edge nick. Mylar is also used for 'potato crisp' packets for this reason, it is tough, but easy to rip open, from the 'nicks' added along the edge.
Because of this anything built with mylar MUST be sealed allong all the edges. either with a tape, or better still folded over (hem-like).
See Plastic Joining above for some construction hints and tips.
Where to buy mylar...
Silver (aluminised) mylar is used by flower sellers to make a bunch of flowers more interesting. You can buy either pre-cut sheets or 250 meter or even 500 meter rolls of the stuff from large florist supply warehouses (their soulkd be one of these in every city). One roll would be enough to supply all your circoflex and other silver kiting (tetrahedral?) needs for a very long time and works out to less than 10 cents a meter!
You can also try a local florist too, though they may not have the range, or be willing to part with the amount you want, and will generally mark up the price.
An alternative source is thin mylar outdoor survival blankets from camping or climbing shops. As a bonus you can not only get silver but a gold look as well (good to fly at weddings :-). This material is probably not actually mylar, but Polyimide (see below), but everything mentioned for mylar applies for this plstic too.
It has come to my attention that some kitebuilders are using aluminized polyester film (Mylar) on their kites. I remember Mylar cobra kites from my youth and wondered why they are off of the market, so I searched the Consumer Product Safety Commission's web site for pertinent information and here is what I found.
BE CAREFUL with aluminized Mylar!!!!!!!!!!!!!!!
The consumer product safety commission made it ILLEGAL to fly kites made of the stuff. After pressure from the insurance industry and the power companies, that is why you don't see them on the shelves of Wal-Mart anymore.
You see, it is conductive.... If you get it across a power line it will complete the circuit between the wires. The aluminum can go into a plasma state that is so hot that it can cut power lines, and the flash is BIG so it can cause retinal damage, that is why welders wear very dark lenses in those hoods when they are making small arcs.
Aluminized Mylar does look wonderful in the sky and I love about a 2 inch wide tail that is hundreds of feet long, but I will not fly it if there is ANY power line anywhere in sight..... You never know where your kite may end up....
Here is a link to the federal law:
Here is the pertinent excerpt:
Two documented incidents...[Code of Federal Regulations] [Title 16, Volume 2] [Revised as of January 1, 2002] [Page 426-431] Sec. 1500.18 Banned toys and other banned articles intended for use by children. (1) Any kite 10 inches or greater in any dimension constructed of aluminized polyester film or any kite having a tail or other component consisting of a piece of aluminized polyester film 10 inches or greater in any dimension presents an electrical hazard and is a banned hazardous substance because its design (specifically its size and electrical conductivity) presents a risk of personal injury from electric shock due to its ability to conduct electricity and to become entangled in or otherwise contact high voltage electric power lines.
It is worth the read if you enjoy flying kites made of Mylar.
Forewarned is forearmed.
"Kapton" is a trade mark (from Dupond de Nemours, I think). The real generic name is "Polyimide". It is not mylar which is polyester. It looks like a survival blanket but more solid. It has one golden side and the other silver, very nice for on a kite! Very very light weight material.
I built my trick-tac mostly with aluminized-kapton and adhesive (3M adhesive kapton and 3M thin double-face glue ...) and with a piece of ripstop for the leading edges and the nose. I only sewed the ripstop where it stands contraint (at the end of the spars : near the nose and for the elastics at the other ends).
My main problem is that kapton seems strong enougth if you tear it, but if you have any begining of rip, it will fall in pieces !!! So it seems to be ok for the leading edges with the ripstop glued on the film.
---- adhesive kapton ----------- 1st pannel ----------- 2nd pannel ---- adhesive kapton
What do you think of Cellophane as a kite material? It seems to be thicker than mylar, but only a little heavier, and does not seem to tear as easily, and it seems to take magic Marker well, yet I don't see anyone in kiting singing its praises, Any idea what makes it non-ideal?
The basic problem with cellophane is that it shrinks with either heat or time. It is a great material for a short term use but it self-destructs after about a month. Because of this kiteflyers usally give up using it after a period of time looking for better materials.
Also beware of cellophane based tapes. I have a fellow kite flyer who used a sticky tape basied on cellophane to repair a mylar UFO kite. A week later, with the heat of his car, the tape had shrunk, and while it remained well stuck to the mylar, the mylar was pulled into a rippled and puckered pattern around the tape. Lucky for him the kite still flys, and the ripples in the silver mylar makes it reflect sunlight in more directions. Look great in the sky but horible up close!
The same is true with using the bamboo barbecue skewers I use for my ''El-cheapo'' kite plans, and tetrahedrals. Though as the quality is usally higher thay can be very strong for their size. However they also become brittle with age (breaking instead of bending) and can easily break in a crash, or when stood on by accident.
However the bamboo, as used by the asian kite makers, is very very strong and flexiable. The reason for the difference is that bamboo blinds and skewers are often made from the weak internal fibres for the bamboo. It is the tough skin of the bamboo however where the bamboos strength is.
The Asian Kite makers when cutting spars for their kites, shave away the the bulk of the internal fibres of the bamboo strip until the desired thickness and width of bamboo skin has been reached. They do not care much about the internal fibres for the plant. By doing this, they can achieve anything from very stiff main spars, to very wispy fighter kite cross spars.
What do you use for the spars on your 1.5 meter Genkis?
As for the main spar in my 1.5 meter wide genki...
I originally to used two 4.5mm fibreglass spars (1.5m) and tape them together to for a stiff but very flexiable rod. This works great for medium to high winds though a turbo tail is recomended. The weigth of that spar tended to give the kite a lot of moment (radial inertia), which ment it tended to keep spinning in loops once it starts. The turbo tail fixed that.
For light winds I now use a 8mm (posibably 6mm) dowel 1.5 meters long with the ends thinned a little and rounded, to fit into the spar pocket. This worked just as well as the fibreglass spar above, is much lighter, and stiffer and will still bows well. The lighness means the kite will fly well in a light wind, but will also take a strong wind too.
For my 2.4 meter wide ultra light genki...
I was using a 9.5 mm wooden dowel 2.4 meter long but have now replaced that with a carbon fibre tube (5.5mm diameter, 3mm internal) feruled in the middle to allow it to be broken down for easy transport.
For a cheap line use a twisted nylon fish netting line, this is good for small cheap "kiddy" kites (about 40cm or less). As it has some stretch it is a must for UFO rotor kite which relay on some kite line stretch to fly properly.
For heavier kites (1/2 to one meter/yard square) a cheap solution is a braded nylon builders line or a light braded dacron line. Dacron is a very soft line which is very easy on the hands and the kite line I use most. For a kite of moderate size (about a yard or meter in size) I would suggest you go to at least a 80 pound dacron.
For Larger kites (2 meter Rokkakus or Cody Box kites) I'd use, nylon venetian bind cord, motor mower starter cord, or a line called spectra core. The later is my preferance as it is light, very strong, almost zero stretch and the polyester braid coating makes it easy on the hands and wear resistant.
Anything larger and you are looking at actual mountain climbing ropes as used for a giant Octopus, Trilobyte and other "show" kites.
For Sports, multi-string controlable kites, you really have only two options. The cheap option is dacron, particulary a very heavy grade when flying very large power kites.
The other is spectra, which is very strong (10 time that of steel), very light, and practically zero stretch. That later means that when you pull you actually pull on the kite and NOT just stretch the kite line. Its drawbacks however is that it is expensive, knots tend to cut the line (dacron sleving is thus required at the line ends), and a low melting point, whcih mean that the cheapest nylon kite line will cut the expensive specrta lines like butter.
Michael Olsen <MDavidO@aol.com> adds...
Also, I found that 100% Nylon (LEIGH brand) mason line (#18) works well for bigger kites. I use it in light winds on my 44 square foot genki.
You can very quickly work out a kites height without mathematics on a standard bit of graph paper. You put the distance between the two observers in the field corners along the base of the graph paper, and then at those points plot the sighting angle from thouse points, where the lines cross you can then read off the height of the rocket, kite or whatever directly.
This assumes that the kite is actually somewhere on the line between the observers but will not be too far wrong if it wasn't.
K /' \ / ' \ / ' \ / ' \ Plot angle from both observers to kite / ' \ / ' \ Flyer is somewhere roughtly between / ' \ __O______F_______________O___ Known Distance between Observers
If you must use mathematics instead of graph paper you can calculate the height from the two observation angles using this formula...
Height = Base × sin(A) × sin(B) / sin(A + B)
Baseis the Base distance between observers
Bare the observed angles from ground.
A Mathemetical method for this is detailed given on Reed Design, Calculating Kite Altitude
Michael Sharon, <email@example.com> on 8 June 1997, wrote...
If you know 2 sides of a triangle, you can always find the 3rd side. If you know you have so much length line out on your kite, that is your hypotenuse. The base, (side b) is the distance from where you anchor your kite to where you walk till your standing directly under the kite when you look straight up.
Now you have the 2 sides of the triangle. Using the basic pythoras's theorem, you can now determine the kites height.
Anthony Thyssen's Reply...
The problem with the above is that humans (us) are not very good at finding the exact point under the kite. Nature just did not design us to know when something is exactly vertically overhead.
Also -- Why walk?
With a calculator, the angle of the kite and the length of line (assuming it does not dip too much due to wind and gravity) you can just punch in the angle get its Cosine and multiple that by the length of line. 2 seceonds work.
Height = Cos( Angle ) × Line_Length
Of course few kite flyers I know know exactly what length of line they have the kite flying on, unless thye have the full length for line on a reel let out. Then kite lines are not straight, but dip into a curve!
I find the easiest method for storing and carrying heavy kite lines is in a bag. Packs easy, comes out clean if you put it in clean, and doesn't take too much room in the kite bag.
This knot will tighten so it will NOT slip like a noose (single larks head) on a large reel, but can if needed still be untied (such as when you swap the end you use for flying from).
Many good parks have a fence to tie the kites to. But too often you don't get that luxury.
I get a coat hanger (with the thick wire) and cut off the hook. I then straighten this out, and cut it in half.
Using one half I bend it into a rectanguler and long U shape...
_________________________ | |_________________________
_ // /(_____________________ '----------------------
----> Wind /\ ______\___________
Note, none of the above methods is really good for kite line reels only the new plastic kite handles, which I used for most of my kites. I also use these for staking out my kit arch. For the beach I use a stake like this made from a full coat hanger, instead of just half a one.
For staking out kites on a beach two good solutions exist...
1) Get a 50cm long stick, log, driftwood, or even bring a few lengths of 4 by 2, tie a spare bit of rope to it and bury it horizontally about a foot down in the sand with the rope stick out. Trample the sand down well and attach the kite to the rope. It will not move at all, no matter how strong the kite pulls or even if the tide comes in. The only time this has failed me was when the stick I chose proved to be rotten.
2) Alturnativally get a canvas sack, like a potato or onion sack, full it with sand and bury that about a foot down.
The best ground stake I have found which is usful in parks with a good top soil, or slightly soggy ground, is a dog stake from the local pet shops! These are corkscrew stainless steel stakes with good handle to tie the kite line to.
You just twist it into the ground as far as it will go and I gurantee even kites which almost lift you off the ground will not pull it out.
I have even found that these stakes also work in sand on beaches though it is probably a good idea to twist them until almost completely buried in the sand.
Line Connectors can range from tied knots in the line (reduces line strength and becomes a nuisance), wrapping the line around machined connectors or eyelets, to pressure clamps. The wrap-around shown below can be made with any hard plastic on a table saw. I have used the ''Hangup'' (TM), designed by Brooks Leffler, in pairs and singly as a line connector. Its configured to allow different line windings; try and use what you feel is the most secure.
Of course the basic forces are needed LIFT, WEIGHT, DRAG, which must be counted by the line pull at the kite, then you have line weight and drag which bows the line (instead of it being straight), etc
Also the lift and drag on various parts of the kite makes a BIG difference in just how stable the kite is. Tails for example can provide both a stabilising drag and weight at the back of a kite.
A wide kite generates more lift (due to more leading edge where lift is generated) while a long kite like a complex box kite, provides more stability.
Then you get the 'wierd' kites...
A UFO rotor flys due to completely different principles of lift generation. While a Circoflex Ring, requires judious use of weights to make the kite heavier below the bridle point and a drag 'lip' at the trailing edge to increase the pressure inside the ring very very slightly, to 'fluff out' the sail and stop it flapping.
The bridle lines also have effects. Short bridles have only a small amount of drag but increases the amount of inward pressure on a cross spar. While a long, and multi line bridle (expecially on a traditional Japanese Edo) can provide a alturnative source of drag for stabailising a kite, insted of a tail.
You can obtain a good geared engine and a radio controlled motor from a servo as follows.
If you open a servo, you can find an electric engine and a control chip. Take off the eletrical circuit and weld two threads to engine terminals, then file the plastic pin stop. Open the rheostat and flat the metallic notch that obstruct full rotation of the rheostat pin.
This geared engine can work from 1.2 to 4.8 Volts and perform nearly 15 rpm. You can replace original rheostat of the eletrical circuit with an equivalent trimmer and place a miniaturized motor instead of the engine and use this device with your radio trasmitter for open a circuit.
I think that this geared engine works very well and is not expensive and easy to find. I have employed this engine in my KAP (kite aerial photograpy), you can see something about this in my site http://users.iol.it/annagalletti/.
This motor would also be good to create a multi release dropper.