Well, I'm not sure why I decided to do this project rather than the others I could have done, but here it is. A horseshoe launcher.
It started with someone making a comment that I should build one, and it hit me that I had all the materials to build a simple one with a pneumatic cylinder and a basic structure. <a href="http://gbcannon.com/pics/hsl/flop1.jpg">Here's</a> <a href="http://gbcannon.com/pics/hsl/flop2.jpg">a few</a> <a href="http://gbcannon.com/pics/hsl/flop3.jpg">pics</a>.
Of course I wasn't too surprised when that didn't end up being powerful enough to throw a horseshoe 40'
I wasn't really planning on going beyond that initial effort...but I did. And big thanks to GGDT because I wouldn't have the slightest clue what kind of launcher would be needed to launch a horseshoe 40' without it.
Anyway, here is what I came up with.
<a href="http://gbcannon.com/pics/hsl/side.jpg">side</a>
<a href="http://gbcannon.com/pics/hsl/top.jpg">top</a>
<a href="http://gbcannon.com/pics/hsl/dummy1.jpg">how the horseshoe fits</a>
<a href="http://gbcannon.com/pics/hsl/dummy3.jpg">another view</a>
<a href="http://gbcannon.com/pics/hsl/dummy2.jpg">where it stops accelerating</a>
<a href="http://gbcannon.com/pics/hsl/extended.jpg">end of rod's travel</a>
<a href="http://gbcannon.com/pics/hsl/front.jpg">front</a>
<a href="http://gbcannon.com/pics/hsl/rear.jpg">rear</a>
<a href="http://gbcannon.com/pics/hsl/rear_assembly.jpg">fill/exhaust assembly</a>
<a href="http://gbcannon.com/pics/hsl/trigger.jpg">trigger</a>
<a href="http://gbcannon.com/pics/hsl/barrel_parts.jpg">"barrel" parts</a>
<a href="http://gbcannon.com/pics/hsl/barrel_connection.jpg">"barrel" connection</a>
<a href="http://gbcannon.com/pics/hsl/piston.jpg">piston</a>
<a href="http://gbcannon.com/pics/hsl/piston2.jpg">another view</a>
<a href="http://gbcannon.com/pics/hsl/piston3.jpg">in the gun</a>
<a href="http://gbcannon.com/pics/hsl/check.jpg">check valve</a>
The valve is based in a 2" cross with ~1.4" porting (1.25" sch40)
The chambers are each 1.5" with a total volume around 35 cubic inches
The barrel is essentially a big pneumatic ram. 3" diameter and 4" stroke. Once the ram passes those holes on the barrel there are 2 more inches to act as an air spring and some .25" neoprene so the pvc doesn't shatter if the ram does contact the plug. (hopefully)
The check valve in the piston is a 1/4" plug and a 1/8" male x 1/4" female adaptor with a spring and a 1/4" BB in it. (It doesn't need to seal perfectly)
I haven't actually shot a horseshoe with it yet, but the velocity predicted by GGDT with the wooden test shoe shown was very close to what it actually was, so I think it should work. GGDT predicts a velocity of 52 fps and a distance of about 80 feet with a real horseshoe at 100 psi. So I should be able to turn it down to 50 or 60 psi for 40 feet.
I still need to add a plate and some padding to the stock as it will probably have quite a kick. And I need to rebuild the piston because I tightened down the check valve more than I thought I could and the spring is pushing it closed too strongly, other than that I am pretty happy with it.
Probably the most useless launcher yet...but it was fun to build.
