Chinese Kites

Actually I don't know much about chinese kites and have next to no experience building them. I have been working on a (small) chinese centipede, though, and thought I might share the information I have collected in the process.

Silk

Untreated silk is porous and stretchy - not very well suited for kites. Chinese kite builders impregnate the silk (don't ask me what they use), rendering it windproof, stiff and reducing stretch.
For my humble kites silk is too expensive and too difficult to work with. I am now using Tyvek for my centipede. Advantages: it can be glued so I won't have to sew curved seams and I can paint it too.

Bamboo

The biggest problem when working with bamboo is, of course, splitting it into thin, straight strips of consistent width - assuming you've been able to procure decent bamboo in the first place (it should be straight, healthy and dry; knots as far apart as possible). Here are some suggestions I've received; I haven't tried them all, so there's no guarantee as to their usefulness:

• Always split down the middle, producing strips of equal widths.
• Don't cut the bamboo, just force it apart. I find I obtain the best results by manually pulling apart the halves after initiating the split with a knife.
• Before using a knife to split from top to bottom, split the knots using a hammer and appropriate wood-working tool.
• Remove the inner skin before splitting. In fact, when splitting very thin spars I first pare them down to the desired final thickness and then split.
• The thickest canes don't necessarily produce the best spars. I'm currently using a 12cm diameter cane and I find the wall thickness makes it harder to split it evenly. It's also a lot of work to remove the excess material. Next time I think I'll select a medium diameter of maybe 5cm.
• "Tonkin" cane is said to be a superior type of bamboo: straighter and stronger.

  The cane [...] comes from the Sui river region in China from a 25 square mile oval piece of land that straddles the border of the Kwangsi and Kwantung provinces, not from Viet Nam. This is an area north of the Tonkin Gulf, about 100 miles northwest of Canton. I believe there are 3 plantations that actually grow the cane. It grows to a height of ~40 ft. before it is cut, and the bottom 12ft. are used for building rods. It has been transplanted experimentally to a number of places, but never grows with enough fiber density anywhere else [...]. May have something to do with the monsoons that hit that region. The particular species is known as "Arudinaria amabilis" which literally means "the lovely bamboo".
  Dan Gracia (DGracia@aol.com)

Centipede

Here's a technique for producing the rings for a centipede's disks: Select a pot which has the desired diameter and fill it with 2cm water. Now produce a strip of bamboo about 5cm wide, bend it into a ring shape and wedge it into the pot. The ends should overlap by approx. 1.5cm; it must be located above the water level. Cover the pot and boil for a while; let it cool; carefully split into thin strips (2mm). Now you have - ideally - 25 bamboo rings. All you need to do is to tie and glue the overlapping ends.

An alternative, suggested by W.Backes in his book "Drachen kombinieren und verketten" is to use rattan for the disk's circumference - only the spars are made of bamboo. This is a lot easier, though less sturdy. It seems OK for my 40cm diameter disks - but I'll have to wait for flight tests to see how well they perform.

Traditional centipedes always have a multiple of 9 disks, since in chinese the words for "9" and "dragon" sound alike. The disks all have the same diameter - in contrast to many plans published in western kite books. Personally I find the former to be visually more appealing.

Here's a beautiful specimen of a traditional chinese centipede. For a modern version of the centipede take a look at Tom van Sant's Centipede

When connecting the disks the final 20% or so should be set to fly at a different angle than the rest; sort of like this (side view - exaggerated angles):

 (head) ... \\\|||||||||||||| (tail end) 

Uwe Hesse suggested a neat sewing technique to attach the sail to the circular frame: stretch the sail over the frame and fold it around; sew a zig-zag seam over the spar - this requires a foot with a matching groove in the middle; trim the excess material from the seam. This technique is fast and produces a nicely stretched sail, provided you maintain uniform tension while sewing.

A very simple low-cost version of a centipede using styrofoam plates is described by Jennifer Snyder (based on a plan by Richard Dermer).