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Discussion Starter · #1 ·
I was reading an old post, and thought some of you could benefit in refining your dart designs with this home made tool ...

http://www.instructables.com/id/How-to-make-a-wind-tunnel/?ALLSTEPS

Test the 0.40, 0.50 and 0.625 (old and new tailcones) darts - use them as a "standard", then test your home made designs to see if you're doing better.
 

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Discussion Starter · #2 ·
Flashback ... June 2006 ... 3rd international sport blowgun competition. New World Record set at 198 out of 210 points! In checking - he used the spearhead darts 0.40 cal. instead of the target darts. (Our bad for not more closely examining - had to alllow it - "Old Wayne" from Lynchburg, VA.). The issue was these dart wires were longer, therefor heavier, therefor had a greater mechanical advantage over target darts. Weight was not taken, but might be 0.1 gm. difference.

Again - a reason to be be very specific about equipment. You want to be comparing "apples to apples".

However, this raises a valid point of discussion ... if you just proortionately size up the target darts, then a 0.625 cal. darts should weight 1.25 gm, not 3 gm. Since the tailcone design by CS is so poor, a light dart like that will never it the target from the standard distance. The tailcone of the 0.625 (new design by CS) is improved, but still not optimal for that caliber. A lot of homemade tailcones look like the film cone darts ("YA") of Japanese design. With a longer tailcone, a longer shaft (for front stability and balance) is needed.

Place a standard 0.40 cal. target dart on your finger to balance it. Note the balance point. Do the same to the 0.50. The relative distance from tip to balance point should be about the same. When you make homemade darts for the 0.625, keep that in mind.
 

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Discussion Starter · #3 ·
Here is another tool for those wanting to create a better tailcone, or making a cone-style (Ya) dart.

Measure the diameter of your barrel. (0.40 cal, 0.50 cal, 0.625 cal. - or self-made) Half that (0.2, 0.25, 0.31) and use that as the height of a triangle.

Measure the length of a commercial tailcone. For a hand made Fukiya film cone dart, or a hand rolled paper dart, use 7.8" (200 mm). Be sure to use consistent labels (inches or mm - don't mix values).

http://www.calculator.net/triangle-calculator.html
Set angle "a" = 90 Set side x = radius (the height you measured) Set side z = length - then hit [calculate] to get the angle
of the triangle. Double that for the angle of cone. Make your cone to those specs.

Compare the angle of the 0.40 and 0..50 commercail cone angles to the commercial 0.625. The greater the angle, the flatter the cone - the more resistance it will have. Optimal angle is a 0.50 cal. Fukiya with a 200 mm length.

Hope this helps.
 
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