Following on from one of my previous threads on Buggies with Skiis, here are the links to the FoilMaker software to design your own twin skin foil kites or pick from tried and tested designs. Once the shape is dailled in it then gives you the option to print the flat pattern to paper ready to cut out and manufacture the kite.
Full installer: http://www.bicycle.eclipse.co.uk/fm/setup.exe
VMRL viewer: http://www.bicycle.eclipse.co.uk/fm/cortvrml.exe
To avoid the MFC71.dll not found error (this happened on my Win2000 system) go to http://www.dll-files.com/
Good place to get tried and tested designs (these also come with the software) a must look is:
http://wingine.nl/ These guys are full on for buggies and kites. Have hints on the sewing aspects as well. And it's in english as well. The kite I will be making first will be one of the junkies. Here are some of the comments from the wingine site on this kite:
"Plans for the Kitejunkie series. The S50 has been a very popular design since its release, being built by foilmakers all over the world, and with glowing reports. Make this foil if you want a cutting edge proven design for buggying." Also a good write up on this junkie kite at:
http://kitelife.com/forum/index.php?showtopic=367&st=0 This a 2004 to 2005 write up, used it for snow boarding and could go upwind. First kite made was a 5 meter. Here are some screen shots of the software:
If you want to see how the profiles work aerodynamically, try xfoil at:
Source: http://raphael.mit.edu/xfoil/ This in turn linked from: http://www.aae.uiuc.edu/m-selig/ads.html For the junkie, using the xfoil software to look at the aerodynamics, if you wish, here is a sample of the pressure distribution.
Note the region just under the nose where the pressure is inward, ie the ram effect can work here. Put it too far up and the air gets sucked out (ie vectors pointing inwards).
The xfoil software is only two dimensional, that is does not examine span wise effects, but will give you a good idea of what the pressure distribution chord wise is going to look like.
Well that's all for tonight.
I had a zipper on my 16m venom 2 give up on me last week. Bloody frustrating, as it was the inflate zipper and I was about to launch ?. The slide was so worn out that it won’t close the teeth anymore.
anyway, I have fitted new waterproof zips to an arc before, but they can be a bit expensive and hard to find. So I thought it was a good chance to test out a Velcro alternative.
its basically just a short sock and Velcro opening similar to the deflates in the flysurfer kites.
the Velcro valves work quite well. I inflated the kite and slowly opened the Velcro. No air was escaping until it opened far enough to for the end of the sock to open.
Sorry, no pictures before they got sewn in. But a few pointers I worked out for anyone wanting to do this mod.
-Make the sock width about 50mm more then the zipper opening in the kite.
- place sticky ripstop inside the kite where the zipper stitching was removed.
- measure from the opening in the kite to the cell wall, subtract 1cm. This is how long the sock needs to be.
-sew the sock in the direction you would use it to inflate the kite (pointing towards the centre)
- sew a deflate valve into the trailing edge to replace the deflate zipper.