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Posted: Thu Mar 15, 2012 12:57 am
by jackssmirkingrevenge
shinyhead wrote:Hopefully I can maintain some control and not launch the first tennis ball at my son at 200+kph, even if the video of it will score some big bucks on "funniest home videos". :twisted:
The line between "Awesome dad!" and "Scumbag dad" is very fine indeed :D

A little side project you might be interested in to quantify your results, all you need is a laptop with a microphone, free audio software and some patience with the math:

http://www.spudfiles.com/forums/homemad ... 12521.html

Posted: Mon Mar 19, 2012 3:34 am
by shinyhead
The line between "Awesome dad!" and "Scumbag dad" is very fine indeed :D
Haha yes, but eloquent timing can make them one and the same :wink:
"Scumbag dad" broke my arm and three ribs with his tennis ball cannon. :twisted:
"Awesome dad" is taking us on a trip around the world with the money he won from Funniest Home Videos. 8)

That "side" project is a definite, once I start my build. Already got the equipment including a paid version of Audacity. I'd love to know how my project is performing before I put it into human testing. (sorry, that last sentence was lies, my son was looking over my shoulder and he so much wants to see the Pyramids, Niagara Falls and the Eiffel Tower! LOL)

Posted: Mon Mar 19, 2012 3:40 am
by MrCrowley
Since I didn't bother hauling my laptop and such down to the nets (and I had no reliable way of stopping 280kph tennis balls in my backyard), I got velocity estimates by just using a basic 25fps video camera and finding how many frames it took for the tennis ball to be fired from 22m away and hit a wire-link fence in front of the camera. It has the benefit of providing you with an average velocity and not a muzzle velocity like what a home-made chronograph would calculate.

Posted: Mon Mar 19, 2012 11:56 pm
by shinyhead
That sounds like a perfect option for me as average velocity is probably more appropriate for my project. Thanks mate.

Luckily footy season is starting so I've got 6 months or so to make this launcher.